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What is the meaning of multicellularity?
I can't understand what multicellularity is. Wikipedia states that any organism having many cells is multicellular. By this definition bacteria can also be multicellular. For example, cyanobacteria can form filaments made up of specialised cells like spore cells and vegetative cells.
But aren't bacteria supposed to be unicellular only? I would appreciate it if someone could clear up my confusion.

Bacteria are, as a general rule, unicellular.  However, there are some, like the cyanobacteria which you referenced, which are kind of border line.  Wikipedia's definition of multicellularity is a very broad sweeping definition, and its statement that bacteria are unicellular is also a broad sweeping statement.
The fact is, that as a general rule, bacteria are unicellular, but at times, like you said, they can undergo filamentation.  When they do, they end up with several connected cells which are generally considered functionally independent.  In certain circumstances, however, the cells can be dependent on each other for survival, and because they didn't separate completely, it's hard to define whether we're looking at multicellularity or symbiosis.
It is generally accepted that cyaonbacteria are truly multicellular.  In order to be multicellular, an organism generally has to fulfill 5 basic requirements:

More than one cell
Cells stick together
Cells communicate
Cells are dependent on each other
Cells are differentiated

By these requirements, some cyaonbacteria technically are multicellular bacteria, defying frequent claims that all bacteria are unicellular.  That said, wikipedia isn't totally wrong, since as a general rule, bacteria are unicellular.  Cyanobacteria are an odd (debatably) exception to the rule.

Sources:

Bacteria with bodies - multicellular prokaryotes, Gould, S.E.
Multicellularity in Cyanobacteria, Paleontology Podcasts
Introduction to Cyaonbacteria, University of California Museum of Paleontology
Wikipedia: Multicellularity, Cyanobacteria, Filamentation

At least on the page "multicellular organism" Wikipedia does not claim that all bacteria are unicellular in contrast, wikipedia specifically mentions cyanobacteria as being multicellular.

Yes, fair enough.  I just wanted to go into why the definition at the top didn't apply for cyanobacteria.

Another species near that border line is the trichoplax that has differentiated cells but can survive being split up into single cells, and can reassemble

The Wikipedia article you mention actually gives cyanobacteria as an example of a multicellular organisms. So yes, there are some (primitive as they may be) multicellular species in the bacterial domain. This should not come as a surprise since a domain in biology is the highest taxonomic rank meaning that it encompasses a huge variety of different species. However, the misconception that all bacteria are single-celled is quite common because it is true for the vast majority of bacterial species.
Furthermore, it is quite common in evolution that similar traits evolve separately (for example flight evolved independently in bats and birds and the claw of the mole and the mole cricket look similar but evolved independently) this mechanism is called convergent evolution. In fact, multicellularity evolved independently at least 46 times in eukaryotes.


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What does the species name 'fistula' mean?
Cassia fistula is tree with yellow flowers. As a medical student what amazes me is that the word fistula implies other meanings. A fistula, at least in medical science refers to a tract with two epithelial openings.

Have you looked at pictures of the plant, especially the fruit? Fistula is the latin word for tube. It is used in medicine, but also in botany. So basically, the word fistula does not only imply other meanings, it has other meanings.

@skymningen could you post it as an answer? Yes now I recall. It has long tube shaped pods. Thanks

The botanic and medical term fistula is directly derived from the latin word fistula meaning tube or pipe.
Both the medical fistula and the fruits of the Cassia fistula tree show phenotypes similar to a tube.
I will spare everyone the medical example picture, but here are the fruit of Cassia fistula, which are sold as "manna":

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


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Can platypuses communicate via electroreception?
I know at least some electroreceptive fish are capable of basic communication with other members of their species via varying their own bioelectric signals.  However, I can't find any information as to whether platypuses (or, for that matter, any of the handful of other electroreceptive mammals) are capable of communicating in a similar manner.  Does anyone know if they're able to do this?

Electrocommunication is used by weakly electric fish only and it is limited to aquatic environments where the electrical conductivity of the medium allows to transmit electric signals. The best studied fish species that use this communication method are The African Mormyriformes (which comprise the Mormyridae or elephantfish and the Gymnarchidae with Gymnarchus niloticus as the only species) and the South American Gymnotiformes (or Neotropical knifefish).[1]
The mammals that are capable of electroreception use it for passive electrolocation which means locating the prey by detecting the weak electric fields of the prey with electroreceptors. These mammals are the three living species of monotreme; the Australian duck-billed platypus (Ornithorhynchus anatinus), the Australian short-beaked echidna (Tachyglossus aculeatus) and the Western long-beaked echidna (Zaglossus bruijnii) of New Guinea; and more recently discovered, the Guiana dolphin (Sotalia guianensis) from the cetacean order.[2][3]
Note: Electroreception was reported in star-nosed mole, Condylura cristata, based on limited behavioral data (Gould et al., 1993) but the theory remains unexplained physiologically.[4]
The electrosensory system of platypus (and probably other mammals) is evolved independently and the electroreceptors belong to the trigeminal system. The physiology of the electosensory system of mammals reveal why they can't use their electroreception for conspecific communication.

In African mormyriform and South American gymnotiform fishes this sense has evolved to an additional active system using an electric organ as a source for a.c. impedance measurement of the environment and for communication. All electroreceptors found in fishes and amphibians that do not have electric organs are of the ampullary receptor type and probably form part of the acoustico-lateralis system. In contrast, the electroreceptors in platypus belong to the trigeminal system. Their sensitivity to d.c. as well as to high-frequency pulses [2] contrasts with the mostly d.c. or lowfrequency responsiveness of ampullary receptors, which are less well-adapted to detect rapid muscle action potentials.
Langner, Gerald & Scheich, Henning. (2009). Electric Senses in Monotremes: Electroreception and Electrolocation in the Platypus and the Echidna. 1056-1060. 10.1007/978-3-540-29678-2_2919.
https://www.researchgate.net/publication/299656487_Electric_Senses_in_Monotremes_Electroreception_and_Electrolocation_in_the_Platypus_and_the_Echidna

References:
1. Map of Life - "Electrolocation and electrocommunication in weakly electric fish"
http://www.mapoflife.org/topics/topic_578_electrolocation-and-electrocommunication-in-weakly-electric-fish/
January 24, 2018
2. Passive electroreception in aquatic mammals.
Czech-Damal NU, Dehnhardt G, Manger P, Hanke W.
https://www.ncbi.nlm.nih.gov/pubmed/23187861
3. Electroreception in the Guiana dolphin (Sotalia guianensis)
Nicole U. Czech-Damal, Alexander Liebschner, Lars Miersch, Gertrud Klauer, Frederike D. Hanke, Christopher Marshall, Guido Dehnhardt, and Wolf Hanke
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3248726/
4. Edwin Gould, William McShea, Theodore Grand; Function of the Star in the Star-Nosed Mole, Condylura cristata, Journal of Mammalogy, Volume 74, Issue 1, 19 February 1993, Pages 108–116, https://doi.org/10.2307/1381909

Further reading:

1. Electroreception (edited by Theodore Holmes Bullock, Carl D. Hopkins, Richard R. Fay)

2. Neurobiology of Monotremes: Brain Evolution in Our Distant Mammalian Cousins
(edited by Ken Ashwell)

3. Sensory receptors in monotremes ( Proske U, Gregory JE, Iggo A.)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1692308/

4. Electroreception in monotremes (John D. Pettigrew)
https://jeb.biologists.org:2083/content/jexbio/202/10/1447.full.pdf

5. Perceiving in Depth, Volume 3: Other Mechanisms of Depth Perception (By Ian P. Howard)

6. Electroreception and Electrogenesis (James S. Albert and William G.R. Crampton) http://www.ucs.louisiana.edu/~jxa4003/Albert%20PDF%27s/Albert-Crampton-Electroreception-proofs.pdf

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


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What are the white eggs growing from a black stem on the Napa cabbage plant?
Are they fungal or eggs?
Can't find anything like this in the internet

Location: South Florida

I believe those are fruiting bodies of a microorganism, probably either a fungus or a slime mold. I don't think they are eggs of an insect or other animal.  The oddest thing to me is the leaves are relatively healthy appearing yet there are dense stands of these bodies.  Perhaps it was feeding on something on the surface of the leaves rather than within the leaf tissue.

Related: Tiny black mushrooms growing from veggies?

I'm no expert in slime molds, but your specimens do in fact look a lot like the sporangia, or spore-producing reproductive structures (i.e., fruiting bodies), of a Mycetozoan slime mold in the class Myxogastria.  Physarum and Comatricha are possible candidate genera based on structure of their sporangia that I can find easily online.
See below for an example image:

 Sporangia of Physarum pusillum. Source: Wikimedia
You can see many photos of the white sporangia of Physarum pusillum here and a close-up of the white sporangium of Physarum pseudocolumellatum here
I don't think I can provide a more specific answer given the quality of your photo or my general lack of deeper knowledge of these organisms. Regardless, no quick search for slime-mold infections in plants produced any information regarding slime mold species that regularly grow above-ground on cabbage.

However, I did find this site which suggests that decreasing the moisture or increasing the salinity of the slime mold's environment will cause it to move along...

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Anyone know what this it?

More than 1 washed up on a beach in Ireland..close to some big jellyfish

Have a look at the tag info for species-identification

Maybe some barnacles?

Gooseneck barnacles
It appears to be a cluster of goose barnacles washed up onshore. This is based on the thick, distinct pedicle and the general shape of the asymmetrical valves. Without more information, that’s as accurate as I can probably get you.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Larva attacking frog ? Guide about this

The above picture was taken in western forest of India where a larva attached itself to a frog neck. What is it and how it will effect the frog?

Maybe an Epomis larva? Just based on the fact that it's attacking a frog. It is not supposed to exist in India, but it does range as far east as Tajikistan, so maybe it's plausible.

Actually it seems there have been two records of Epomis in India.


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Help identify this small spiney praying mantis?
Trying to identify this praying mantis for a short film. It's found on the wild cosmos flower. It's found when the flower is in bloom at this time of year (February) in Harare, Zimbabwe.

This appears to be a species of Sub-Saharan flower mantis in the genus Pseudocreobotra.
Specifically, it resembles the spiny flower mantis Pseudocreobotra wahlbergi.

 © 2013-2018 carlarush
The species gets its name from the spiny structures on its abdomen. According to Wikipedia, the color is variable:

being typically greenish, but it can equally be yellowish, pinkish or reddish

According to here, you can determine the sex of your specimen by counting the "abdominal appendages" (i.e., spikes):

females have just 5 abdominal-appendages on the underside, however males have 6

 © 2004 Steffi Schuttauf
This might also be P. ocellata, which would be able to be distinguished from P. wahlbergi based on its smaller adult size [source].

That's fantastic, thank you so much for the identification. I will be sure to send you the short clip when completed. Many thanks from Zimbabwe

No problem @WildZimbo. Don't forget to click the checkmark to indicate  the answer as "accepted" if you're satisfied. Thanks!


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During non-cyclic photophosphorylation, how does NADP+ become NADPH?
I know that NADP+ gets reduced to form NADPH, but what exactly is being donated? Is it two individual electrons (from photolysis or the chlorophyll molecules) and a hydrogen ion (proton)? If this is the case, during the Calvin Cycle, do the NADPH molecules donate the same two individual electrons and hydrogen proton from the light-dependent reactions to become NADP+ again? Thanks.

SE Biology expects you to show what research you have done to answer this question (the title of which should be repeated in its body). Just googling for "non-cyclic photophosphorylation" gives the answer to your title in a  callout box at the top of the page.

All electrons are the same; they are indistinguishable

Specifically during non-cyclic photophosphorylation, I know that the chlorophyll already has preexisting NADP+ molecules, water is broken to release 2 hydrogen atoms and 1 oxygen atom (two water molecules break down to form gaseous oxygen that we breath), those 2 hydrogen atoms get sent down and along the Electron Transport Chain via solar energy and then I believe one goes to a protein called ATP synthase and the other goes to photostem 1. After photostem 1 that hydrogen binds to free floating NADP+ molecules to from charged NADPH. This should be the gist of it all but I would also recommend listening to someone else's input as well.

Wait, I thought that photolysis splits water into two electrons, 1/2 of O2, and two hydrogen ions which are just protons. I'm pretty sure the hydrogen ions contribute to the H+ concentration, not to the photosystems because that's where only the electrons go in which they ultimately end up reducing NADP+

Okay, I've done some research and yes thank you, that was the part that I was forgetting. The positive hydrogen ions go through the ATP synthase while the electrons follow the ETC, after phyotosystem 1, I believe those electrons will diffuse because they repel while the hydrogen ions are also repelling each other (keep in mind they are both outside of the thylakoid membrane now). This I believe results in the electrons and hydrogen's coming back together to later be randomly paired up with NADP+ molecules.

At SE Biology we're looking for answers that provide some explanation and context. Explain why your answer is right, using citations. How is the poster to be able to check whether your answer is correct?

First, "I believe" is what shows your lack of effort to give a nice answer. Second, the OP themselves stating that you give wrong information in your answer is exactly what is not expected from answers on SE (or at least Biology.SE). Please show some research effort for an answer (this is probably the first time I have said this here)

Thank you @another 'Homo sapien' and David, I'm sorry for the lack of effort.


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What insect is this, large swarms?
I live in Brisbane, Australia and these creatures arrived a few weeks ago for a day or so and then they disappeared. There were thousands of them. I would love to know what they are.

That is some sort of ant. Many species of ants have this huge "nuptial" flights, particularly after rains, where winged males and females leave the nest in swarms. Males die shortly after, while females lose their wings and start a new nest in the soil. I'm not familiar with Australian species, but the fact thatyou can see a "waist" shows you that those are winged ants.


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Bird species ID in the Northern Territory, Australia
I was visiting Darwin, NT, Australia a few years back and I encountered this bird. I must say it was in Darwin's Botanical Gardens, so I can't be absolutely positive the Northern Territory is its original habitat. However, I'm pretty sure it's a NT native, as the whole Gardens were packed with, and dedicated to NT's wildlife.

The photo is kind of dark and a bit fuzzy due to poor lighting conditions. I already tried to digitally enhance it by removing shadows and so forth.
I tried Google Images reverse search to ID this bird, but I'm not a hero with that tool. Although it looks a bit like it - it's definitely not a Jabiru.

That's an Australian White Ibis (Threskiornis moluccus).

It's widespread across much of Australia:

You can find more info on Wikipedia.

Can't accept it yet due to system limitations -- but wow that is quick - thanks!

I was just in Australia this year, so I recognized the species fairly quickly. "A Pocket Naturalist Guide: Australia Birds" was a useful tool while I was there.

Oh thanks for that pic of Oz - I was already wondering whether it truly was native in SE and NT - it's a big country!


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Storage DNA Condition
It is possible to store a digestion of cells with lysis buffer several days at -20 degrees and then proceed with the phenol chloroform isoamyl purification?

Strictly speaking your answer will depend on what you want from the sample and QA requirements etc - can you elaborate a bit?

Should be fine, but if I were you, I'd spare a few more minutes and carry on until ethanol precipitation (15 min of work at worst). Here's the protocol:
https://www.thermofisher.com/pl/en/home/references/protocols/nucleic-acid-purification-and-analysis/dna-extraction-protocols/phenol-chloroform-extraction.html
You can store it in -20 degrees for several days (extend the overnight incubation, that is the second step of ethanol precipitation) and you'll have the certainty that it will stay ok. In fact, freezing in most buffers, whether lysis buffers or extraction buffers shouldn't significantly hurt any nucleic acids. From my personal experience: I've frozen plant material in extraction buffer for RNA isolation (TRI-zol method) in -80 for a few days and got very high concentrations in most samples in the end. I was told freezing in -20 would impact quality but RNA is generally less stable than DNA.
If you had little to none material, you're better of doing the precipitation procedure and then freezing it. If those are minuscule amounts and/or you work with something sensitive like forensic evidence, following through with the procedure will be the most reasonable solution.


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Sex determination in cephalopod?
I see some source say octopus do not have sex chromosome. So what's the sex determination mechanism for cephalopods?

Welcome to Biology.SE. Can you please link to this source?

Related: Do males of all sexual species have Y chromosomes?

@Remi.b  They may be referencing this 2003 whelk paper: Genetic sex determination, gender identification and pseudohermaphroditism in the knobbed whelk, Busycon carica (Mollusca: Melongenidae)
John C. Avise1, Alan J. Power2 and DeEtte Walker.

Or this 2007 paper trying to find the same answer: Causes of variation in sex ratio and modes of sex determination in the Mollusca—an overview  http://www.bioone.org/doi/abs/10.4003/0740-2783-23.1.89

So far, you're right in that there is no hard method of determining cephalopod sex determiners.  Male and female share the same number of chromosomes, but are morphologically different, with the male developing a special arm for transferring spermitangia and the females often being larger than males (1).
Most research papers seem to focus on just being able to tell the sexes apart by behavior/anatomy (2) and have not yet broached on the How, except to note that they do not seem to have specific markers, which you've already noticed (1).
You can tentatively run with this, and keep an eye out for new research in Google Scholar, and decide that your race uses environmental signaling (3) to determine their sex.  Given how real life nature goes, you'd probably be in the clear as certainly one cephalopod species will use that method to determine sex. It also can segue into sequential hermaphrodism if you're interested in going in that direction.  It would certainly bring a novel element to your sophonts, rather than making an octopus "human". (Hypothetical extrapolation based on the previous version of this question in Worldbuilding.stackexchange)
But, to give you some ideas for environmental factors.  Some species of Daphnia will make parthenogenetic males when three factors meet: a short photoperiod, shortage of food and a high population density (4). The ever popular crocodiles have temperature dependent sex-determiners, with a narrow "sweet spot" to get a 50/50 male/female clutch (5). The green spoonworm determines it's sex as a larvae, if it lands on the seafloor it becomes female, if it lands on a female it becomes male and lives as a parasite inside of her.
Until further research, develop some form of environmental conditions that can be met naturally, or generated by intelligent octopi for what you want this question to answer.
(1) Coe, W. R. (1944). Sexual differentiation in mollusks. II. Gastropods, amphineurans, scaphopods, and cephalopods. The Quarterly Review of Biology, 19(2), 85-97.
(2) Mercer, M. C., Misra, R. K., & Hurley, G. V. (1980). Sex determination of the ommastrephid squid Illex illecebrosus using beak morphometries. Canadian Journal of Fisheries and Aquatic Sciences, 37(2), 283-286.
(3) Rider, C. V., Gorr, T. A., Olmstead, A. W., Wasilak, B. A., & LeBlanc, G. A. (2005). Stress signaling: coregulation of hemoglobin and male sex determination through a terpenoid signaling pathway in a crustacean. Journal of experimental biology, 208(1), 15-23.
(4)Kato, Yasuhiko; Kobayashi, Kaoru; Watanabe, Hajime; Iguchi, Taisen (2011). "Environmental Sex Determination in the Branchiopod Crustacean Daphnia magna: Deep Conservation of a Doublesex Gene in the Sex-Determining Pathway". PLoS Genetics. 7 (3): 1–12. doi:10.1371/journal.pgen.1001345. PMC 3063754 Freely accessible. PMID 21455482.
(5) Janzen, Fredric J.; Krenz, James G. (2004). "Phylogenetics: which was first, TSD or GSD?". In Nicole Valenzuela; Valentine A. Lance. Temperature Dependent Sex Determination in Vertebrates (PDF). Smithsonian Institution. pp. 121–130. ISBN 978-1-58834-203-4.


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Which mammal produces the most milk?
I'm searching for the mammal species that can produce the most milk during lactation. I Googled it, but it says dairy cattle which biologically speaking is not right answer, because a baby whale can drink up to 150 gallons (> 550 litres) of milk per day (according to whalefacts.org). So which mammal can produce the most milk?

I'm looking for volume but if you can tell about fat content too it would be appreciated : )

Define "most", because I think you will find that dairy cows which produce everyday will outperform whales which only do so for part of the year in total milk output.

By "most" I mean a mammal who can produce most milk whenever she lactate. I'm  editing my question to make it more specific.

What happens if you “normalise” but dividing by body mass for example? Ie remove size...

Blue whale should be the answer. You can deduce it based on given info and if you compare to other mammals. It is also mentioned in this (non-credible) source: https://www.intoyard.com/do-whales-have-nipples/

In animals, such as the blue whale, that fast during lactation, nutrients are mobilized from tissues (maternal reserves). Supply is mainly limited to body fat; thus, total available supply is proportional to body mass. Body weight of a blue whale is approximately 120,000 kg (at the start of the nursing period) and lactation duration in this species is 210 days (7 months). According a published paper (Oftedal 1993, J. Dairy. Sci. 76), "a female blue whale arriving at the feeding grounds weighing 80,000 kg might gain 40,000 to 50,000 kg before migrating to low latitude waters to give birth. This stored mass is assumed to be lost during the 7 mo of lactation; thus, milk production can be predicted to be 27,000 to 33,000 kg, which is equivalent to about 23 to 25% of initial maternal BW. During this period, suckling calves gain about 81 kg/d, or a total of 17,000 kg, which corresponds to a predicted milk intake of at least 26,000 kg. These two estimates are reasonably similar and indicate milk production of about 30,000 kg milk, or 140 kg/d". Production per cow is lower (in the United States it averaged 23,391 pounds for 2019, United States Department of Agriculture (USDA)).
About your second question (fat content), true seals (Phocidae) exhibit the shortest and most intense lactations, with extremely rapid weight gain in their pups. Hooded seal lactation duration is only 4 days (briefest lactation period in mammals). Hooded seal mothers secrete milk, which contains 60% fat, at rates of 10 kg/d (Iverson et al. 1995 J. Comp. Physiol. B 165).


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Why do some animals have beards?
Why do some animals such as some Goats, Ibex, Orangutan etc, have long well-shaped beard like men?

Probably for the same reason men have beard.

Apparently, the "sexiness" of beards is conserved in the animal kingdom.

@Frieke Some biologists argue that beards have less to do with female choice per se, but more to with intrasexual competition and status hierarchies. So a male beard may have more to do with intidimating other males than females finding them sexy. I'm not saying that this is true necessarily; I just wanted to note  that I have seen it been argued.

@Eff: yes indeed. Growing a long beard is costly (concerning resources but also potential handicap). Being able to afford a nice beard is showing dominance among males and attractiveness for females. Maybe I should just put this into an answer.. ;)

In humans and animals beard growth is usually restricted to males, since it's dependent on hormones (testosterone or, specifically, according to wikipedia it's dihydrotestosterone). By no surprise it starts growing during puberty.
But why?
Growing a long beard is costly concerning the necessary resources but also because of a potential handicap. Being able to afford a nice beard is showing dominance among males and attractiveness for females. It could be seen as a direct display of high testosterone levels. This is comparable to peacock feathers. They are very impractical, but have great value for showing dominance and attracting females.
I think, there are many psychological theories around to explain the attractiveness of beards. Some might also be meaningful in animals. Apart from cultural, religious or hipster beard trends, we generally consider old men with long beards as wise and knowledgeable. In animals the beard might also signal social status in groups, additionally to male dominance and sexual attraction.
Further reading:

Importance of hair in humans and hormones involved
Sexual attraction of beards in humans
Trustworthiness of bearded men
Intrasexual competition influencing sexual dimorphism (here: size)
Sexual selection
Costs and benefits of male hair (lion mane)

The research of animal beards is pretty sparse, but hair at the chin is just one of many "appearance traits". So, I provided some studies about various aspects of sexual selection and human psychology that give explanations.

Further reading: https://en.wikipedia.org/wiki/Handicap_principle


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What species of short plant is this in Iran?

Anyone knows the name of this Iranian local species?

Hi welcome to Bio.SE! Please see our guidelines for writing a good species ID question. After reading the guidelines, please update your post accordingly. Otherwise, unfortunately, it'll be downvoted or closed. Thanks.

it's a chalk area species which is very generic, without a bloom photo it looks similar to 100ds of other species. You therefore need a mountain plants book specific to iran and local chalk areas.


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Insect/cocoon ID?
Can anyone ID this? We’re in the Rocky Mountains, Western US. We found it stuck to the wall of our garage, a few feet up, hidden behind a snow sled. It seems to be covered, or surrounded, in what looks like mouse hair. Is it a moth? It’s hard to see scale, but altogether about the size of a thumb.

I would guess this is the cocoon of a moth in the subfamily Arctiina in the Erebidae family.
For example, see this example of an Isabella Tiger Moth cocoon in Kent Co., Maryland from The Maryland Biodiversity Project:

 Credit: Nancy Martin
You can find additional images of various species here, here, here, and here (seen without the cocoon).
According to here, Pyrrharctia isabella (or the Isabella Tiger Moth shown above) is sometimes found in the Rocky Mountain region of the US, but I am not knowledgeable enough about these pupae to definitively point toward a species.
Based on the experiences of many others, I would advise not touching this with bare hands or clothing.


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What is this insect in winter?
I came across a bunch of these tiny ball-pen-sized insects that (to me) look like they belong to the beetle family. They are all dead but I do remember seeing it once flying in my apartment. They are as small as fruit flies.

I think you're right that it's a beetle, but the picture quality (which I realize you may not be able to improve) will likely forbid anyone going any deeper than that.

@user please put more effort into your posts regarding grammar, capitalization, and spelling. This is a site intended for professionals, not yahoo answers. They will get downvoted. Regarding your question: I agree with Arther -- looks like a beetle, but the photo quality makes an informed ID rather difficult

"This is a site intended for professionals..." Has Stack Exchange implemented a new policy recently? This site is not "intended" for any specific, named group of people. The site is open to everyone, and strives to be open and welcoming to all, especially new contributors.

@theforestecologist That wasn't very nice or welcoming. Not everyone here is a native English speaker. If you have an issue with someone's grammar/spelling/punctuation, feel free to edit it or ask for clarification (I see you did edit this one).

@L.B. misspelling (and not correcting) words while using a built-in spell-checker and not capitalizing words like "I" are not an ESL issue; they're indicative of a rushed post or a lack of professionalism. Grammar is less necessary, but I did not tell the OP to write perfectly -- rather, I requested politely that they put adequate time/effort into writing a more professional post (as is suggested by our help section).

@theforestecologist Not here to argue. However, issues like not capitalizing "I" actually can be ESL issues and especially with a phone's autocorrect, that is a very common issue. I'm not defending making lots of mistakes. I am defending the person because we don't know them personally and they are asking a legit question and simply made mistakes.

@uhoh it is intended for a specific group. From our tour page: "Biology Stack Exchange is a question and answer site for biology researchers, academics, and students". Of course, anyone is welcome to use this site & we strive to make that experience helpful as much as we can. However, we do have standards (see here & here), & posters are expected to meet those standards.Voting/commenting are our tools for promoting adherence.

@L.B. sure we don't know anybody personally, which is why we have a code of conduct. And that's why I asked politely (see the use of "please"), and then followed-up by editing to show them their mistakes. It's a learning process, but one which requires pointing out a misstep. We can't just pretend everything is ok.

@theforestecologist okay that works because anyone who wants to learn can be considered a student. So we can agree that "This is a site intended for professionals..." is probably not the right way to paraphrase?

@uhoh professional in regards to conduct and style, not in regards to level of expertise. In other words, I was referring to professionalism

@theforestecologist yep that works.


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What is this plant disease that causes raised blobs in the leaves?
I found this plant in Borneo with seemingly diseased leaves. The leaves have raised reddish blobs. What could be the cause of such deformities?

I don't know a specific answer, but in addition to pathogens like bacteria, viruses, and nematodes, also consider gall-forming insect.

@Flux Could you please confirm a specific location? There are multiple places in the world that could be referred to as: Borneo. This is in the Gall and Rust mite Family, but in order to confirm a species I need a specific location.

Not a disease per se (at least not caused by any fungus, bacteria, or virus, which would not lead to raised bumps). Most likely these are galls caused by parasitic eriophyid mites.
Without a more specific location or more specific info about plant species/etc. on your post, I will not try to identify specifically.

note: not that it much matters, as the specific species is not likely described. From Wikipedia:

About 3,600 species have been described, but this is probably less than 10% of the actual number existing in this poorly researched family.

Instead, I'll show you similar looking growths caused by maple gall mites:

 Image source: University of Wisconsin-Madison Extension


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Why is "VOLVOX" not considered to be in PROTOZA?
Volovox is an Algae, but it moves with the help of Flagella. Protozoa has members that move by Flagella. Why is Volovox taxonomically in the Algae instead of Protozoa?

Algae are also not a taxa (it is an ecological group)

Protozoa is an archaic term that is no longer taxonomically valid because it is paraphyletic. A "protozoan" may be used as a generalized descriptive term of a motile single celled eukaryote, but Protozoa is not a taxon.


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What kind of bug is this one?
We are trying to figure out what kind of bug this is? It appears to have larvae on its back it is not dust and debris.

It is some sort of Neuroptera

Karl's answer is about as far as we can go without size and locality information, and by the way, that is debris on the animal's back ...

It looks like an earwig to me, they're great parents too, lugging all their young around with them.

This is a kind of neuroptera larva https://www.google.com/search?q=neuroptera+larva.
The smooth jaws discard an antlion https://en.wikipedia.org/wiki/Antlion.
Is more like a chyrsopidae https://www.google.com/search?tbm=isch&q=neuroptera+larva&chips=q:neuroptera+larvae,g_1:chrysopidae:qWI0Ngq4zAQ%3D. They like to camouflage with debris found around them.

i cant really tell but, the op's photo doesn't look like it has hair on its leg, antlion definitely has hair on its legs. But you know cant really tell


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What is this and is it dangerous?

Is this some type of moth, it looks dangerous is it?
I have only seen something like this once before.
Thank you for any information you can give me.

Where did you find this insect?

Black and red, probably dangerous! In case you don't know for sure, don't play with it.

better to say which region / country and what kind of habitat you found that.

That's a wheel bug (Arilus cristatus), a species of assassin bug named for the wheel-shaped projection on their thorax. They tend to prey on pest insects, but they do "bite" humans with their proboscis. The result is an extremely painful, itchy welt, though non-venomous.
These one's don't attack unprovoked, however, so generally just when trying to handle them. You should handle them with gloves.


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ID large-thorned plant growing in Turkey
Can anyone identify this plant which is growing in a friend's garden in the Uzumlu area of Turkey. It has very large spikes/thorns. I'm told it doesn't have flowers or seeds so we are wondering how it propagates itself.

This is a palm (family Arecaceae). Many palms have spines; I'm no expert but it looks to me like it is a member of the Phoenix genus, perhaps a Cretan date palm (Phoenix theophrasti). Date palms do propagate themselves by seed (the pit of the date fruit). The palm in your picture, if a date palm, would be rather young, which could explain why it does not presently show flowers or fruits. Here is a photo of the spines and flowers of a Cretan date palm (by Wouter Hagens, from Wikimedia Commons):

It is very unlikely that this is Phoenix theophrasti, which has a very limited range. See, for example, the wikipedia link you posted: "with a very restricted distribution", giving quite specific info on where in Turkey the plant can be found.

@GeorgeWilliamRussel'spen, it may well be a different palm, but the natural range of P. theophrasti (or of other species) probably isn't all that relevant, as the OP's image suggests the palm was purposely planted as part of landscaping.

It's listed as NT by the IUCN, and as stated has a very limited range. It is very unlikely that P. theophrastii is planted as a part of landscaping or gardening. You would have to know about it in the first place, and then obtain a speciment. It's not a common plant, and to the best of my knowledge rarely planted.  P. dactylifera and P. canariensis are much more likely. And we can't tell from the picture.


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Identify this mite from Rajasthan (India)

Can anyone tell me the classification of this bug? I found it in Rajasthan after it rained.

What’s the scale on the picture? It looks like some kind of mite, but those are generally < 1mm in size

red velvet mite of some kind. they get pretty big

Also, please update your question with approximate size of the organism and the habitat you found it in (for future reference). thanks.

Hi it definitely looks like a red velvet mite.  They often are called "rain bugs".  They are of a variety of species and sizes and can be quite large - up to 1 or 2 Cm. These links might help.
https://study.com/academy/lesson/red-velvet-mite-facts-life-cycle-diet.html
https://en.wikipedia.org/wiki/Trombidiidae
https://www.youtube.com/watch?v=OtHYSIRCZ1c

This is a Trombidium mite (class Arachnida).

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Mint twisted like a spiral
My friend has a mint plant with a spiral-shaped stem, and the leaves are positioned like this:

Why could such deformation happen? Other mint plants, growing in the same pot, are normal.


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Farsightedness and the eye
When a farsighted person looks at a distant object and sees it clearly, what is the state of their eye lens? Is it relaxed?
Rationale:
It is something we read about in class that is confusing.I know a person with 20/20 vision would have a relaxed lens when looking at a distant object. I think a farsighted person would have a relaxed lens when looking at far objects since they can see distant objects, but since they have trouble seeing close objects the lens would not be relaxed when looking at close objects. Those that are nearsighted would have a relaxed lens when looking at close objects, but not when looking at distant objects. So, a relaxed lens just means the eye does not need to strain when looking at something?

Is this a homework question? Please show us what have you researched so far regarding this. Maybe something from optics chapter?

related: https://biology.stackexchange.com/questions/30504/what-is-the-difference-between-myopia-and-hyperopia?rq=1 - does that answer your question?


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What is this flower?
I was in Germany recently, and I saw again a flower that I'd only ever encountered before at Meijer Gardens. It's interesting to me because I'd never seen a flower with color variation in only the 'interior' petals. Try as I might, however, I can't seem to find it anywhere! Can anyone tell me what this is? I'd like to be able to learn more about it.

Are you asking about the violet flower or the white/pink one?

For the violet/purple I would guess it is some variety of petunia. (Sorry, I wanted to edit my comment but that guess came 1 minute too late to do so.)

The white/pink one, I probably should have made that more clear.

It's Verbena hybrida Voss (See here; the page is in French though).

It belongs to verbena genus in the family Verbenaceae. It's about 10 to 50 centimeters tall with a squarish stem and opposite leaves.The flowers are small with five petals, and borne in dense spikes on the top. Verbena hybrida Voss is always used as ornamental plant. They are drought-sensitive, tolerating full to partial sun, and enjoy well-drained, average soils. It's always plant in warm and dry and sunny environment. About why a flower with two colors in one petal, it's because there are always two kinds of pigment in the petals. The pigments in different temperature and different acid alkaline environment present  different colors. When the flower is open, the acid-base property changed will lead to petals present different colors (K. Yoshida et al., 2009).

What is meant by Voss. Is it a subspecies?

It is the authority of Verbena hybrida. In Linnaean binomial system of nomenclature, authority name adds after plant name. But sometimes, Verbena hybrida is all the same.


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is this a brown recluse spider?
What kind of spider is this? SE Michigan, light brown color, second picture less focused but w tape measure for scale. Thank you!

Here's a good image of a brown recluse: https://upload.wikimedia.org/wikipedia/commons/c/cc/Brown_Recluse.jpg. Notice the characteristic violin shape on its head.

No, this is not a Brown Recluse.  There are several reasons for saying that, among them the fact that it's outside; it's hanging on a screen, and it doesn't look at all like a Brown Recluse - (Recluses don't have a rectangular cephalothorax "head end", and they have a bulbous abdomen, not that pointy-ended one this spider has).
As for what it is, there are some good clues - first that rectangular-looking cephalothporax.  That's pretty unusual in spiders, although it's not actually rectangular; it's just the central dark pattern is very blocky.  Then, look at that color - kind of a creamy light mahogany rather than a real brown, and no darker/lighter patterns that the bigger wandering spiders that look like this would have.  Finally, look how it's holding its legs - both the front pairs are close together.  That's something you tend to see in two sorts of spiders - the big Argiope orbweavers, and the big Fishing Spiders and their relatives.  Argiopes have a different body shape, pattern and color than this, and it would be a little unusual to find one this size hanging around not in a web.  Fishing Spiders are generally dark-colored, and with more patterning than this, but there is a close relative that fits this image:  the Nursery-web Spider, Pisaurina mira.  Here's the Bug Guide page, and a representative photo:
https://bugguide.net/node/view/2919

John, excellent descriptive answer. I always appreciate how knowledgeable you are regarding spiders. Is this based on experience / collected knowledge, or do you use a key/guide? If the latter, which resource do you use?

Yes to echo @theforestecologist these are the sorts of species ID answers that I really appreciate: those giving a description of the attributes that led an expert to their conclusion. Well done, thanks for your work.

Thanks - unfortunately, up until recently, there really weren't any particularly good field guides to spiders.  There was the Zim Golden Guide, which had some common species, and fairly recently there was the Audubon photography-based Insects and Spiders, which had a few species as well.  I learned using the very good Kaston lab guide, and collecting spiders enough to learn the various groups by eye.  It's not too hard; just takes time and practice (and an interest in learning about spiders, of course).  Nowadays there are several good websites, of which Bug Guide is the best.

If I was learning now, I think it would be a bit easier because Richard Bradley's really excellent book covers many of the more common species, and does it very well.  Still, there really is no substitute for field observation, so you can recognize the patterns of stance, shape/colors and behavior.  You may not know the specific spider, but you generally have a guidepost to help you narrow it down.  It's like with birds and trees and flowers, but without the useful pocket guides..


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What type of butterfly or moth is this?
Can anyone please determine if this is a moth or butterfly and what its name? We found it near a waterfall in the Philippines. There's actually a bunch of them and it seems that it's their natural habitat which is close to the waterfall and a stream along.

That is a butterfly known as a "Mapwing". It is in the family Nymphalidae. I'm pretty sure it is Cyrestis maenalis. https://wikivividly.com/wiki/Cyrestis_maenalis

I see. Thanks you so much for the info.


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Spider Identification (UK)
I found this spider (~10 mm body length) indoors on a wall (South-East England) and I was wondering what species it was.

My first guess is false black widow, but I can't be sure.
I'd be grateful if anyone could help me out.

Yes, it's Steatoda, probably nobilis, the False Widow.  The white band curving around the front of the abdomen is a good Steatoda diagnostic, and the light-colored abdominal pattern is pretty variable in this species - only hints of it here, but the pointy front end and the bits of a skeletal 'shield' pattern are there.
The spider is pretty harmless, although it is supposed to sometimes give a bite that's like a very mild Widow bite.  Not at all dangerous, but a little more potent than the usual harmless spider bite.
Below are a couple of pictures of nobilis, showing a range of markings:

Here is a citation describing the effects of S. nobilis bites that's not a fear-mongering tabloid story:
https://www.researchgate.net/publication/320623444_Envenomation_by_the_noble_false_widow_spider_Steatoda_nobilis_Thorell_1875_-_five_new_cases_of_steatodism_from_Ireland_and_Great_Britain
The images were taken from a random survey of Steatoda nobilis images from the internet, as a broad selection was desired.  However, this note (below) discusses some of the features I mention, along with photographs that support my comments.
https://cisr.ucr.edu/european_spider.html


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Is there other unknown-compound in Blood?
Blood is made of red blood cells, platelets, plasma etc. Let's say, then, there are these $x$ known compounds in blood.
But how can one be sure that there is no other compound other than those $x$ compounds? Does present technology ensure that there is no other unknown compound in blood that can't be detected?

@user1136  so, there is a probability that we don't know all the elements of blood, yet, right?

It all comes down to our ability to detect materials in blood. It would be impossible to rule out the existence of substances below the limit of detection, but would these materials have any significant effect at such low concentrations?

You might be interested in reading about proteomics and metabolomics. Both approaches are  capable of untargeted detection and identification of proteins or small molecules, respectively.


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What kind of spider is this? Bolivia
Can anyone help me identify this spider found in Cochabamba, Bolivia. It is quite small. This photo shows it on a normal mortar layer between brick.

It's a (possibly subadult) female Black Widow. Subadult females often have some level of red or red and white markings on the upper surface of the abdomen, and females of some species retain those markings even into adulthood - the notorious Redback (Latrodectus hasselti) being an examnple of that. Black and red is a very common "Danger!" signal in nature, so you should be a little leery when you see it.  This one looks like Latrodectus mirabilis, which Garb, Gonzalez and Gillespie have marked in the area of Bolivia. I know almost nothing of this Widow, but since most Black Widows are pretty similar in their habits and venoms, I feel pretty confident in saying that you probably do not want to get bitten by this spider. It would be extremely painful, and would probably give you a couple of very bad days until the effects eased up. Widows don't usually tend to bite unless physically injured, but you probably want to shake out your boots in the morning before putting them on..
Here's the link to the Garb paper:
Garb, J.E., González, A. and Gillespie, R.G., 2004. The black widow spider genus Latrodectus (Araneae: Theridiidae): phylogeny, biogeography, and invasion history. Molecular phylogenetics and evolution, 31(3), pp.1127-1142.
And here's a nice Spanish language blog
that features this photo of L. mirabilis:


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What is this seaside thing?
I found this on the sand and I do not know what is it? I thought it is sea devil, however I checked google and it is not. Can someone tell me what is it(its name )

Please include your location and the approximate size of the specimen. This will ensure you get the most accurate answer and will best make this post useful to others in the future. Thanks!

It looks like a worn-down water chestnut. Water chestnut fruits are often found along the shoreline and bottom of waterways - they have very sharp spines with barbs that can cause painful wounds when stepped on. Water chestnut is an aquatic invasive plant that is native to Eurasia and Africa. It was introduced in the United States in the mid-1800's as an ornamental plant. Around 1884, water chestnut was found growing in Collins Lake near Scotia, NY. Water chestnut colonizes areas of freshwater lakes and ponds and slow-moving streams and rivers and negatively impacts aquatic ecosystems and water recreation.
https://www.dec.ny.gov/animals/109536.html


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Black and orange spider, what is it?
Found in Alexandria MN, on sidewalk. Small, fast little spider.

It looks to me like one of the Amaurobiidae - the Hacklemesh weavers, often called Lace Spiders for their fluffy, cottony silk snares/shelters that they spin under rocks and logs.  It's an adult male from the big boxing glove pedipalp structures in front of the face, which is presumably why it was out in the open; it was looking for love.
As to which one it was, I'm not entirely sure - these are not a group I'm too familiar with, and I don't even know what species are found in Minnesota.  It looks a bit like a male Amaurobius ferox (an introduced European species that is spreading across the country from eastern N. America), but even lightening the photo doesn't help reveal the abdominal pattern, I'm afraid.  I'll just go with "probably Amaurobiidae" and suggest you send the photo to Bug Guide for the attantion of the pros over there:  https://bugguide.net/node/view/6/bgimage
Here's a representative male A. ferox for comparison, but note that this is a well-lighted photo so you can see the pattern on the abdomen.  Also note that there is a fair amount of individual variation in these (as in most) spiders, so some are darker, some are lighter, some have obvious patterns, some are more poorly-defined, etc.


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Identification of an Australian pigeon in the NT
This pigeon was spotted in Darwin, NT, Australia. I am not able to solidly identify it using my books or google searches. My best bet is a Torresian Imperial Pigeon (Birds of the NT website).

Do you have any other pictures?  Torresian Imperial Pigeon seems like a fair guess, but a better shot of the beak,  feet, or -- more importantly -- its tail feathers or covert feathers could help confirm that.

@theforestecologist - I know! But unfortunately this is the only pic I have from the bird. A pity for sure. The tail of the imperial pigeon is black and that seems a strong marker imho, but I don't have it on camera.

I'm just not sure too many other species are all white with black under the wing like that. The next best guess is the closely related Pied imperial pigeon. That species  is more concentrated in SE Asia,  but seems to show up in zoos worldwide, so could be an option in Northern OZ

@theforestecologist - Thanks for all your feedback. I'm not an ecologist - I'm a fake Biologist as I always say (i.e., a medical one) - so please feel free to vote to close if it is too unclear.

I've expanded upon my comments to make a full answer. Hopefully it provides some closure :p.

@theforestecologist - He&& yeah mate, cheers.

Your bird appears to be an Imperial Pigeon of the Ducula genus. Based on the limited angle of the lone picture of your specimen, my best guess as to the species is the Torresian Imperial Pigeon (Ducula spilorrhoa).

The species is a relatively large, pied species of pigeon found in various habitats (forest, woodland, savanna, mangrove and scrub) in Australia (including in the Northern Territory where you saw your specimen), New Guinea and nearby islands.
You can see more pictures, videos, and calls here, as well as additional info here.
Your specimen is unlikely the closely related  Pied Imperial Pigeon (Ducula bicolor) because:

D. bicolor is a  Southeast Asian species

D. bicolor has a bluish grey beak, whereas your specimen and D. spilorrhoa both have a yellow beak.
Note: Your specimen is also unlikely Ducula subflavescens because the feathers are white and not yellow, and it is unlikely Ducula luctuosa because that species is endemic to only a few islands.


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Difference between Sphyraena obtusata and Sphyraena novaehollandiae
"Striped barracuda" is the common name for both Sphyraena obtusata and the Sphyraena novaehollandiae.
Here's links to both fish species from fishesofausralia.net: S. novaehollandiae and S. obtusata
Are they the same fish just found in different parts of Australia, or are they completely different species? If they are different species, what is the difference between them?

I think you may have looked at these species too quickly.
They are in fact different species.
Sphyraena obtusata is referred to as the obtuse barracuda, the striped barracuda, or various other names that your linked website (fishesofausralia.net) provides:

Dingo Fish, Obtuse Barracuda, Pike, Sennit, Short-finned Seapike, Short-finned Sea-pike, Short-jawed Sea-pike, Striped Sea Pike, Yellowstripe Barracuda, Yellowtail, Yellowtail Barracuda, Yellowtail Sennit

Sphyraena novaehollandiae, on the other hand, is referred to as the Australian barracuda, arrow barracuda, Australian sea pike, sea pike, snook, or shortfin barracuda.

Even your linked post doesn't provide "striped barracuda" as a common name for this species.

Differentiating the two species:
Your fishesofausralia.net links demonstrate these fish are found on different sides of Australia (S novaehollandiae in the south and S. obtusata in the North of Australia.
The Wikipedia articles for these fish (linked previously in my answer) indicate that S. obtusata only reaches maximum lengths of 55cm, while S novaehollandiae can reach sizes exceeding 1 meter.
Both sources also list a number of additional color and morphological variations you can use to differentiate the two species.

@AshleyS if this adequately answers your question, please consider accepting the answer. Thanks :)


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Exact meaning of the term "clutch"
When reading a Wikipedia article to do with chickens, I have come across the term "clutch", but I was not able to entirely figure out what this word means. I was wondering whether the term clutch can be used to refer to any set of eggs by birds, reptiles, and amphibians, or whether a clutch must consist of a set eggs all by the same bird, reptile, or amphibian. In general, if a typical clutch by a well fed chicken amounts to a dozen of eggs, that seems like a lot of eggs for a chicken to hold within its body prior to laying them, hence my question about clarification and about what number would actually fit (I have seen as high as fifteen). It is this simply the number of eggs expected to live concurrently in a typical nest where more than one chicken would breed?

A clutch usually refers to all the eggs for a single reproductive event or laying or location. It can mean either all those laid by one organisms in one event or all those laid in a population in a single time and place. Which is usually clear in context.
Even just for an individual it is a bit vague however and can refer to one laying or multiple layings if they happen close together in time.
There is also a usage difference by specialization, agricultural scientists tend to favor a boarder usage for instance.

Thank you for your answers. Could you please indicate what other areas of specialization that make use of such a term "clutch" exist besides agricultural science? Thanks.

Could you please also identify the typical and maximum number of eggs which may sit in a chicken's body? Thanks.

chickens lay around one egg a day, so there clutches are built incrementally, average clutch size is around 12 eggs. rarely does more than one fully developed egg sit in a chickens body, the key term is fully developed.

As for other usages, everything from paleontology to ethology. basically any branch of zoology could be dealing with eggs

Well, strictly speaking from an etymological viewpoint, a clutch is:

"a brood, the number of eggs incubated at any one time," in reference to chickens, 1721, a southern England dialectal variant of cletch (1690s), noun from cleck (v.), which is from Middle English clekken "to hatch, give birth to" (c. 1400), which is probably from a Scandinavian source (such as Old Norse klekja "to hatch"), perhaps of imitative origin (compare cluck (v.)). Compare batch/bake.


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What is the largest species of polychaete?
My Google searches seemed to avail no results. My question is: What is the largest living species in the class Polychaeta?
That's about it. I understand that there will be few accessible weights for these worms so length will suffice.

According to the Smithsonian:

The longest of all known polychaetes was found in Port Jackson, Australia. It was a member of the family Eunicidae, consisted of approximately 1,500 segments and was nearly 6 meters long when alive.

The Eunicidae consist of numerous species (including the super cool bobbit worm), many of which get fairly large.

Though, typically 3 m in considered quite large for worms in this group (e.g., see Uchida et al. 2009 for a description of a 3 m long Eunice aphroditois).
Polychaetes & Allies: The Southern Synthesis also suggests that members of Eucinidae can reach 6 m in length. From p. 94 of this report from the Australian Biological Resources Study:

Eunicids have many segments and may attain a length of up to 6m...
...Eunicids range from less than 10cm to 6m in length, and consists of up to 1500 segments (Fauchald 1992a).

Supposedly, according to Schulze 2011:

The Australian museum even holds a specimen that reportedly was nearly 6 m long when
collected (Fauchald 1992 and pers. comm.)

Salazar-Vallejo et al. (2011) also cite evidence of 3+ m long polychaetes in the genus Eunice as evidence that the genus is "the largest polychaete species and placing them among the longest benthic invertebrates."

None of these worms compare to a species of ribbon worm (phylum Nemertea) called Lineus longissimus that can reach 55 m in length! [Sources: 1, 2].


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What is this African bug?
This is an arthropod I found in an apparently abandoned mongoose burrow in the Maasai Mara game reserve, Kenya:

That was the best photo I could get of it. From what I could tell, it had six legs and very long antennae, so I'm guessing it's an insect. It was vaguely orthopteran-like and had striped/banded legs with a dark dorsal side.
Does anyone have any idea what this could be? Even if the species can't be discerned, I'd appreciate knowing what clade this critter belongs to.

Based on the long legs and long antennae, I'd say you're correct that it's an orthopteran, very likely a cricket or one of its allies (i.e., suborder Ensifera).
Within this subgenus, the most likely candidate families are either the "true crickets" (Gryllidae) or "camel crickets" (Rhaphidophoridae).
Your photo is not nearly good enough to begin making more informed specific guesses. However, If I had to guess, it could possibly be a cricket in the genus Phaeophilacris, which are striped-leg crickets found in Africa.

See inaturalist for incidence of this genus in Africa.

You can see some photos of Phaeophilacris Bredoides here, with a few photos copied below:

 Source
You can read an interesting paper about communication in this genus here1

 1. Heinzel, H.G. and Dambach, M., 1987. Travelling air vortex rings as potential communication signals in a cricket. Journal of Comparative Physiology A, 160(1), pp.79-88.


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What species is this orange and black caterpillar from Costa Rica?

Does anyone know what type of caterpillar this is? I don't know much about them. Pictured it in January in Costa Rica cloudforest (Monteverde) and am using it in a speech for visiting Costa Rica.
Size about 3,5-4 inches.

This looks like a caterpillar.

Millipedes and centipedes have chitin segments.  millipedes actually have anywhere from 40 to 400 legs. centipedes have between 15 and 177.

Looks like a caterpillar in the Saturniidae family

Probably it is Cricula silkmoth (Cricula trifenestrata, Saturniidae), in caterpillar stage.

but this is from costa rica? Cricula trifenestrata is found from India to the Philippines, Sulawesi, Java, and Sri Lanka.

Similar, but not the same. Cricula trifenestrata had white hairs coming out of the red bulbs. The picture above has black, branched hairs.


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Do birds change their diet before migration?
Migration takes up a lot of energy, so I am wondering if birds (in my case mallards) change their diet / food preferences in the weeks before migrating. Do they select for more energetic foods to fuel up, or do they just eat more of the same foods to gain enough energy?

Apparently, yes. This article underlines the changes in diet in semipalmated sandpiper before its 3000 km-long migration:

Near the beginning of their journey, sandpipers stop at the Bay of Fundy on Canada's eastern coast to gorge on mud shrimp, 1-cm-long crustaceans loaded with omega-3 fatty acids. Over 2 weeks, the frantic feeding doubles each sandpiper's body mass [and i]t makes sandpipers' muscles use oxygen more efficiently, enhancing the birds' endurance.

The authors experimented the diet on a similar species to disentangle the effects of the different diet from other effects, for example due to hormonal changes:

To isolate diet's role, Weber and colleagues took exercise and migration out of the equation. They turned to the bobwhite quail, an unrelated sedentary bird that doesn't migrate and seldom flies. For 6 weeks, the scientists fed 40 couch-potato quails a combination of omega-3 fatty acids from fish oil. To the researchers' surprise, the quail's oxidative capacity - their muscles' efficiency at using fuel - shot up 58% to 90%.

This paper reviews the effects of diet changes on the digestive trait of migratory birds; however, it's quite old (2001).
I couldn't find any indication on mallard feeding prior to migration, but these links can be a start for further research.

Geese can build a lot of fat reserves before migration, it's the reason that Fois-Gras is made, because the goose can keep lots of fat in it's liver.
You can buy Spanish foisgras which is made naturally by letting the geese fatten on nuts and rich autumn foods.
Birds generally eat whatever they can get, as rich a diet as possible in protein and carbs, but it's dependent on seasons. So the diet changes anyway at that season, independently from the birds energy requirements. https://sora.unm.edu/sites/default/files/journals/auk/v098n01/p0065-p0079.pdf
"The natural cycle for the wild goose of Europe is to spend the summer in Denmark, Sweden, Norway, northern Germany or parts of Russia and Ukraine. Then they migrate south to Africa each autumn," Labourdette explains. "They stop here in Spain on their way, to eat and gain energy for the long flight. But lots of them never leave because they find such a good habitat here."
Geese are adaptable, he says, and they eat whatever the environment provides. Foie gras from Denmark has a fishy taste, because the geese eat seafood there. Here in Spain, they feed on calorie-rich acorns, olives, figs and seeds.


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Identification: Is this really a case of Progeria?
There are some news about a boy being born in Bangladesh that looks very aged and presumably has Progeria: http://metro.co.uk/2016/09/29/newborn-baby-who-looks-like-an-80-year-old-after-being-born-with-rare-ageing-condition-6159215/
To my knowledge, humans born with Progeria looks quite normal at first, and it's not until after birth that the associated symptoms start to develop.
Is it plausible that this actually is a case of Progeria? Is there any other syndrome that would better match the appearance of the boy?

Not that it matters, but it appears the baby was born in Bangladesh.

@SrihariYamanoor Thank you, I've corrected it.


text:
What diurnal red & black moth is this?

Seen today on a hot summer day in Stockholm, Sweden. Length around 25 mm.

Looks like a six-spot burnet (Zygaena filipendulae)

Diurnal moth of the Zygaenidae family.

Description:

has a wingspan of 30–40 mm (1.2–1.6 in)...The fore wings are dark metallic green with six vivid red spots (sometimes the spots are merged causing possible confusion with other species such as the five-spot burnet). Occasionally, the spots are yellow or even black. The hind wings are red with a blackish fringe. The larva is plump and hairy with variable markings, usually pale green with rows of black spots.

Habitat:
meadows, woodland clearings, sea-cliffs and rich, grassy/flowery areas.
Range:
common throughout Europe, June - August.
Sources:
wikipedia


text:
Questions about insects eating flour and living in the cracks of a wooden cutting boards
I have a large wooden cutting board which is used in my kitchen mainly for preparing egg pasta. The wood type is Populus (poplar or aspen or cottonwood).
The main ingredients used with the cutting board are: flour (mainly soft wheat flour), hens' eggs, white sugar, butter, and baking powder.
After the food preparation, the cutting board is cleaned by scraping away the ingredients remains.
The board has some cracks and some small unknown insects are living inside the cracks.
The board has also a lot of holes due to woodboring beetles but I think the woodworms operated long time ago and they no longer live in the cutting board.
The unknown insect has an approximate length of 1 mm (along the direction of their movements) and a width of 0.3 mm. The unknown insects do not have wings, they just walk. I am not able to see how many pairs of legs they have.
The color of the insect is pale brown.
The cutting board was free from these unknown insects some months ago but then they appeared.
My questions:

What insects are they?
Are these insects poisonous to humans?
How can I get rid of them?

Update
The unknown insects could be Acarus siro, I will try to get a picture of the insects.
Update 2
Here is a picture. The bottom part of the image is a one Euro coin, the top part of the image is a caliper (each bright area is one mm tick).

Some more pictures:

Can you show an image of the beetles?

@Chris There are no woodboring beetles in the cutting board, there are just their holes. Unfortunately I do not have a suitable camera equipment to take a picture of the unknown insects I am asking about, they are too small (1mm x 0.3mm).

Buy a new cutting board. :P (plastic ones would solve all your problems). We can't ID a bug without a picture, either.

It sounds like a flour beetle, try the red (or rust red) flour beetle, though they are more than 1mm in length. You can probably kill them by putting your cutting board in the oven at 250° for an hour or two.

@anongoodnurse Does the flour beetle have wings?

@anongoodnurse I treat them with Ethanol 95% so, at least, they will get drunk :-)

No, the flour beetles are flightless. If you look at google's images (there are three main kinds of flour beetles; red is the lightest), you should be able to tell, especially from the head shape, which it is, if any.

@anongoodnurse Red flour beetles are not flightless. Beetles have their flight wings hidden under a protective shell that is made from specialized wings. Also, flour beetles are a potential source of allergens, so if you're making these noodles for other people, I'd get a new cutting board. If you're the only one eating the noodles and aren't allergic to the beetles, it's up to you.

@user137 - you're correct. It's the confused flour beetle, which it closely resembles, that can't fly. Thanks for catching that.

That picture does not look like a flour beetle. Almost looks like a termite. Don't know if the size is consistent with termites.

The pictures aren't very good, but just for the sake of it I'm going to put Springtail (Collembola, primitive hexapod) out there as well. It fits well size-wise (<6 mm, often less than 1 mm) and they have quite diverse morphologies. However, they are connected to moist environments, and it seems unlikely that a cuttingboard would be the main point of infestation. They might hide in cuttingboard cracks thought. It's not the Acarus siro from your update 2 (eight legged mite)

I agree with @user137 that termite is a possibility (antennae look a bit off though). It is definitely not a flour beetle.

Neither flour beetles nor termites get that small.

This is a species of psocid (of the family Psocoptera, AKA booklice).

Species are best differentiated by their abdominal structure and antennae. Without a better (more magnified) image and info about the OP's location, identification to species is not possible. Though its small size will definitely narrow the options.
If I had to guess based on the limited detail (and my limited knowledge), I'd say it's a species in the genus Liposcelis or related genera.  See Oklahoma State's ENTOPLP ID key for examples and info. I've included 2 random images of Liposcelis species for reference: the (TOP) is Liposcelis brunnea and (BOTTOM) is Liposcelis corrodens.
You can find info about prevention and removal from Oklahoma state, King's College London or the Orkin man.
UPDATE: Though I, myself, cannot identify this psocid to species, according to this KCL article, Liposcelis bostrychophila is the most likely candidate. [See here for ID notes].

From the KCL article:

Liposcelis bostrychophila is the principal psocid pest species in the UK and in Europe. This single species, which is mainly an inhabitant of households, is responsible for virtually all of the psocid related complaints in the UK (Turner & Ali 1996)...Recent estimates are that 30% of households contain this species.
Several other small (about 1mm long), flattened, wingless liposcelid species (eg. Liposcelis corrodens, L. pearmani and L. brunnea) can become quite common in industrial sites, particularly in the summer months but are uncommon in domestic premises.

The insects are in the northern part of Italy.

@AlessandroJacopson: Thanks for the location update. Though after reexamining your low-resolution photos closer I don't believe they contain the detail necessary  to identify this psocid to species. I think this might be the best ID you will receive. If you're satisfied, please accept the answer. Thanks.

I agree with the ID (and have upvoted) but, just for the record, this could be improved by responding to "How can I get rid of them?" within the body of the answer (you use an external link for this) and also by addressing "Are these insects poisonous to humans?".


text:
Locomotion of Hydra: Why Somersaulting is better than Loop locomotion when moving to a larger distance?
In my text I read about different types of locomotion of Hydra where I learnt that generally Hydra moves by somersaulting and it is faster than 'Loop locomotion' which Hydra uses for moving to a large distance. At the end of the chapter the question is "Why somersaulting is better for going to a larger distance?" I cannot find a good answer to it.

Is not saving time a good enough argument?

generally Hydra moves by somersaulting and it is faster than 'Loop locomotion' which Hydra uses for moving to a large distance. by 'Which' I mean 'loop locomotion' so in fact, when Hydra goes to a larger distance it chooses the slower process


text:
Are some facial features more important than others in human facial recognition?
I'm often surprised by the human ability to correctly identify other individuals despite significant modifications due to ageing, hairstyle, injury, etc. But, sometimes the addition of a beard and a hat can radically increase the identification error.
I wonder whether all facial regions are equally important when we try to recognise human faces? Do we focus more on some regions than others? I doubt that this is the case, but I'm not certain.
Update:
So far I've read through the following:
1) http://en.wikipedia.org/wiki/Face_perception
2) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2998394/
So far I haven't found an answer so I decided to try Biology.StackExchange.

Have you done any background research of your own? I'm pretty sure that there are quantitative research on this, e.g. on how humans scan faces (i.e. our eye movements) and the amount of time we focus on different facial features. I strongly suspect that the eyes + areas closeby are very important, so I would imagine that changes there will increase errors.

I have read through http://en.wikipedia.org/wiki/Face_perception and http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2998394/ but so far I haven't found a conclusive answer to this question. Hopefully an expert on this stackexchange will be able to answer.

Look for facial recognition software algorithms. They seemed to have figured something out about it. Distance from pupil to pupil etc....

@rhill45 While interesting, this is something completely different. Even if we have identified software algorithms that are effective in identifying faces, this does not mean that we as humans (with behaviours molded by evolution) use the same cues/features when we recognize faces.

And for the record, I don't understand at all why this is closed as opinion-based. This an interesting Q, answerable by quantitative methods (brain activity when looking at facial features, eye scanning of faces etc), and on-topic for the site. It could be closed due to a lack of background research (@AidanRocke, you should add your summary of the Leipold & Rhodes paper to your Q, and what questions that remain after reading this), but I don't see why it would be opinion-based.

@MattDMo
Why is this question closed as opinion based? It appears that scientists are currently working on this question. Please explain.

@AidanRocke Your update is not including any new info, besides you saying that you've read something - not what you've learned and where you are stuck. Just by looking at the paper you've linked, there are several interesting papers/reviews to look into further (see section Components of face perception: identity).

The most important features are the eyes, followed by the nose and mouth, respectively.
An elaborate answer can be found on the duplicate question on Cognitive Sciences SE:
Are some facial features more important than others in human facial recognition?

Will format question link once I am off mobile

Hmm.. Chris did you check who posted that question on cogsci? It is the same OP and the Same Answerer too! lol

Good one Chris! Cross-site duplicates are not closed as a policy (from what I gathered in my stumbling through meta), though cross-posting is not encouraged. I think you should elaborate your answer in both sites. Even duplicating your answer is good

@Crags - thanks! What I understand is that a link to a cross-site is OK. Bio people not at CogSci can still find it that way. I will leave as is.

Link is definitely Ok. Just explain what you want in detail in one site and post the link with summary in the other! Yes, leave as is


text:
What are these tiny, swarming, jumping bugs?
I built a small plywood box in my yard (on Long Island, NY, USA) for some stray cats about a year ago. I didn't bother waterproofing the box, and so over time the box has gotten damp.
About two weeks ago I started seeing small reddish brown bugs on the box, and in the food/water dishes near the box. Can anyone help identify them? Here are some details:

there are 100s of them
they're really small, the biggest ones are about the size of a sesame seed
they jump when disturbed, usually in an upwards direction
they don't seem to go on the cats
some venture 2-4 ft from the box to find food dishes on the ground (concrete patio)
they drown themselves in the water dish by the dozen
they're more active when it's warmer (~ 45°). When it's cold (25-35°) they mostly hide somewhere

All of this makes them sound like fleas,  but they're not fleas -- they don't jump as high or have the flat body of a flea. They actually look like arachnids. OK that makes them sound like baby jumping spiders - but I've seen baby jumping spiders at work, and these look different (they're reddish brown, not black, and they don't jump in an "across" direction, they jump upwards, kind of randomly). Maybe they're a different type of jumping spider, but why haven't they moved on? Why are they taking up residence on the box, instead of spreading out and going their separate ways like baby spiders usually do?
They're are about the size of a sesame seed so it's hard to get a good picture.
EDIT: new picture collage:

Related to: Bug Identification: Tiny Bugs in Fairport NY, Help identifying tiny jumping bug, Can Anyone Identify This Insect?, Taxonomy: Categorising Collembola, What kind of small insect is this?, Unknown aquatic larvae

Very useful image updates! These are actually not arachnids but hexapods called springtails (order Collembola). Although springtails are often very tiny and hard to see without a lens, you happen to find some "larger" specimens. Specifically, these appear to be some species in the family Dicyrtomidae.

 Credit: M. Bertone (source)
Your species resembles the image of Dicyrtomina minuta seen here or Dicyrtomina saundersi seen here (though I can't be certain of these source's accuracy).
In general, springtails usually feed on decaying matter, and -- you guessed it -- they're known for their ability to jump!

Springtails are so-called because they have a unique structure, the furcula, that allows them to jump for considerable distance relative to their tiny size. [source].

 Springing mechanism of a generalized springtail. Credit: Marianne Alleyne [Source]
According to NC State Extension:

Rarely springtails may become exceedingly abundant and may congregate in heaps several inches high on driveways, sidewalks and poolsides.

Collembola.org has many excellent close-up images as well as detailed descriptions of nuances and sexual dimorphism seen in the Dicyrtomina group of springtails.

I found some close-up pictures of similar lookign species here


text:
Import of H+ ions into the thylakoid space during photosynthesis in plants
Why are H+ ions pumped into the thylakoid space as the electrons pass through the cytochrome complex from PS2 to PS1 during photosynthesis?

This is covered in most texts of biochemistry. Have you tried to find the answer yourself as explained in the Help Centre? Try, for example, Section 19.3 of Berg et al. online.


text:
What kind of fruit is this? It is the size of a small avocado or a plum

The flesh inside them seems ripe as it is squishy, and it gives off a strange odor. The smell at first reminded me of menthol. It's about the size of a small avocado, or a plum. A coworker of mine left a few on my desk before he left, but he didn't say what they were.

My cat definitely hates the smell. She reacted more strongly to this than to citrus.

Were did you find them? On a tree, on the market? Which country? Etc.

And please add an approximate size.

Might be a Kwini. Mangifera odorata

Please add more information about where this fruit comes from. (I upvoted your answer and downvoted your question)

After doing a bit more research and asking a few friends, I found out that it was a feijoa, or pineapple guava. I think the ones in the picture aren't fully ripe yet, though.


text:
Help identifying this bird from Southern Brazil

I've seen a few of these birds at my university located in the extreme south of Brazil.
I noticed they usually stay on wet areas and like to eat small critters, such as worms and young tadpoles (I'm not completely sure about the last one).
I also noticed they usually stay alone in a particular area or, at maximum, two in the same location.
Also, here we also have many Southern Lapwings, which are in the breeding season, and one of them sometimes attacks the bird in the picture (for apparently no reason). When attacked by the Lapwing, this bird bristles the feathers of his neck and just dodges the Lapwing's attacks.
Does someone know what bird is this?
P.S.: Sorry for the bad picture. I couldn't get closer to it.


text:
Is there any biological evidence that is not suggestive of or seems to disprove evolution?
Often, in science, when we have evidence that doesn't fit our paradigm, we bend it until the paradigm collapses.
Although there is plenty of decent evidence for evolution, is there anything that does not fit the evolutionary paradigm? Is there any biological evidence that is not suggestive of or seems to disprove evolution? Or is everything merely hunky-dorey?

all evolution or just some? Human evolution has not been fully outlined yet. We know the process, but we don't have a clear A to B to C if that's what you mean. If you mean evolution as a whole then no. Evolution deniers from my experience tend to disapprove of carbon dating, stating that carbon dating is wrong and hence all calculations done with it are wrong. However, even most Christians nowadays don't support spontaneous creation, but rather believe the ancient Hebrew word "yom" means a period of time not a 24 hour day.

I'm not sure whether a one-word answer is allowed, but "No" would seem perfectly adequate.

@Charlie Is carbon dating even relevant to evolution? C-14 has a half-life of about 5000 years, and going back too many half lives reduces the accuracy. If we assume a 10 half-life limit for reliable measurements, that's still only 50,000 years, which is almost meaningless on an evolutionary time scale.

Evolution is a broad field of knowledge. There are definitely a few elements of our current theory of evolution that does not perfectly match observations. However, those concern small details and might not of much interest to you. Here are a few examples

We don't know the relative importance of background selection and selective sweep at explaining genome-wide variation in genetic diversity.
We don't really have much of an idea what fraction of speciation happen in sympatry.
We don't understand well how recombination rate evolves to differ in different genders.
We don't really understand what are the limits and/or costs of phenotypic plasticity that makes phenotypic plasticity less frequent that we would otherwise expect.
We don't really understand the patterns of genetic diversity on sexual chromosomes at the intersection with the pseudo-autosomal region (PAR).
We don't fully understand how much expansion load (a type of mutation load caused by the sampling of individuals at the expansion edge of a population) there is in human population.
We don't really know whether the mitochondrion (and other double membranes organelles) was first a endo-parasite or a endo-symbiont.

If you are asking whether there are evidences suggesting that evolution is not happening or that humans and chimpanzee do not actually share a common ancestor but were created independently, then no, there is no such evidence.
You should have a look at the related post Is Evolution a fact?

Please clarify your question. Evolution per se is an observation, not a theory. We see it literally every day (I am a virologist and my organisms literally evolve on that time scale). It is impossible to argue rationally that evolution doesn't occur; it's like denying that when I spill my coffee the mess falls downward. Even pre-Darwin scientists universally accepted that evolution occurred. Even "Creation Scientists" (who are not scientists, but religious fundamentalists) can't deny that evolution occurs. Evolution is a fact, not a theory.
Are you asking if the theory of evolution through natural selection (which is what most people think "the theory of evolution" is, and what religious people call "Darwinism") explains everything? No, of course not. It's a theory that is over 150 years old, and it hasn't been the sole theory underlying evolution for over 50 years. Other theories, including sexual selection, neutral drift, and nearly-neutral drift, were proposed in order to account for many aspects of observed evolution that natural selection doesn't account for.
If there were other aspects of observed evolution that weren't accounted for by one or more of these underlying theories, then further theories would be proposed. Evolutionary theory is pragmatic, not dogmatic.
At the moment, there are no observations I'm aware of that can't be accounted for by the present combination of theories.

I agree with Remi.b that there are some things we don't yet fully understand. However, Darwin got it right. A theory is an explanation of observations. It is laid out to be disproven. Evolution, as a theory, has stood 158 years of attack without being disproven. It predicted Mendelian genetics, and molecular biology. Sexual selection seems to be outside natural selection, which is why Darwin considered it a special kind of selection. The "theory" is as strong as science can ever support. "Facts" and "proofs" are for math. But if we had any proof that evolution did not fit our observations, the theory would be falsified.

Please do not fall into the common mistake of confusing theory and hypothesis. What you describe is a hypothesis, a theory is backed by solid  evidence and can be used to describe experiments. See here for more details.

I am fully aware of the difference. Evolution is among the most highly supported theories that is fully supported by experimental evidence.


text:
Help identify the insects I keep finding at my house (Auburn, WA)
Could anyone tell me what is this living being is called? I keep finding his relatives flying/crawling in my house once in a while since late Summer this year. We live in Auburn, WA, in case it helps narrowing down the list of who it can be...

Knowing the name will help me figuring out:

whether it's dangerous for my wife, or our infant;
how to get rid of it (I start suspecting they either breed inside the house, or somewhere very close because I only find these insects when it's getting warmer outside).

Sorry for the low quality of the photo. By the way, this animal is about 15mm or 5/8" long (not measuring the legs).

It is a Halyomorpha halys, commonly known as a stink bug.  Your photo shows a brown marmorated stink bug.  More information can be found on this Wikipedia page.

As far as your two questions:

Stink bugs do not normally bite people and are not poisonous.
A good way of controlling them in your home is by sealing any
openings that they are entering through.

Source: http://stinkbugsguide.net/facts.htm

Wow! That was fast! Could you tell me how did you do that? Some kind of a book helped you, or you just 'happened to know'?

We see them all the time at our house-most commonly in autumn. I think it was my oldest child that knew what they are - I think he learned about them in school.  My children like to catch them and let them go outside.

I wish I knew a permanent solution to this problem. These buddies freak my wife out, and I'm not very comfortable with catching them... Still, many thanks, Kurt!


text:
Whose horns are these?

Can anyone please help me identify these horns?
I guess they belonged to either European or Asian species. I don't know anything about their history -- they are my grandparents' who are from Moscow, Russia. The horns are at least 20 years old, I guess even more.
The length from the tip of each horn to its base (straight line) is about 35 cm = 13.7 inches.
A friend of mine suggested those might be a cow's horns, but I'm not sure.
Maybe someone can recommend a resource where it's possible to find it out?
Thanks in advance!

Hello Elizaveta, there are a couple of facts needed to ID a specimen related to living organism; like size and background of the specimen (in this case history of this wall mount).

Hello and thank you for your suggestion! I will update my post.

A single picture of aged and polished horns is not going to be that easy to give a confidently correct answer, but I can at least say that they appear to me to be horns of a yak or cattle steer.
See for example, the horns of a female domesticated yak (Bos grunniens):

the horns sweep out from the sides of the head, and then curve forward; they typically range from 48 to 99 cm (19 to 39 in) in length. The horns of females are smaller, only 27 to 64 cm (11 to 25 in) in length, and have a more upright shape.

Wild Yak (Bos mutus) have similar, though smaller and sometimes curvier horns:

The Wild Yak’s horns are grey to black and curve outwards, forwards, back, and slightly inward. The horns of males are larger than those of females. The horns of male Wild yaks average 42.6 centimetres (16.8 inches) in length, from tip-to-tip, and 35.2 centimetres (13.9 inches) in circumference. The horns of females average 32.2 centimetres (12.7 inches) from tip-to-tip and 19.5 centimetres (7.68 inches) in circumference. [Source].

 Yak (Bos mutus) in the Lüneburg Heath wildlife park, Germany. [Source].
Both Yak species are present in Asia:

Though there are over 12 million domestic yaks in the Central Asian highlands, fewer than 10,000 Wild yaks survive.

However, as I said, these could just as likely be the horns of any of a number of variety of steer cattle. (There are over 800 varieties!).
See for example, this Corriente cow in California:

If you Google "steer horns" you get dozens of shapes and varieties of mounted horns. You could comb through looking for similar specimens...

If I had to guess, since your grandparents are from Russia where yak are present, it seems to me it would be more interesting/impressive to mount yak horns vs just steer cattle horns. But that's just a personal guess.
Here's a picture showing a variety of species and their horns:

Not sure of the source of the last picture, but if you figure it out, you might gain access to another 25 horn types! :p

Thank you so much for your answer!! I appreciate your help!


text:
What kind of skull is this?

We found this skull on a beach in southwestern Sweden, and are curious as to what kind of animal it was.

It's definitely a bird pelvis (synsacrum). Based on the size (~30 cm), it came from a very large bird. Unfortunately, comparative images of bird pelves are rare on the internet. Some possibilities (large birds of Sweden possibly found on the coast):

Great northern loon
Golden eagle
Common crane

A loon skeleton (from http://paolov.wordpress.com/2011/08/05/friday-mystery-object-107/) shown below.

Thanks for your prompt response - you must be right. We have looked at some alternatives - a cormorant, perhaps, or a goose?

The top of the synsacrum in the loon isn't flat enough to be a good match. I know that loons have strange pelves, so that was my best guess. Whatever it is, it was a very large bird.

Crane looks like a decent match, see link, in geese and gulls it is mush shorter and squarer, https://www.researchgate.net/figure/Ventral-view-of-the-synsacrum-fused-with-the-pelvis-A-and-their-scheme-B-in_fig4_259319680


text:
What type of Insect Egg is this?
Can you please tell me what type of insect eggs these are? I found them in the corners of my office kitchen behind boxes and cardboard. Found them in between the broom bristles. Found them along the edge of the wall. There are quite a few of them.
If you could please provide me some tips on how to avoid getting these eggs or killing off the main insect would be helpful.

I doubt they're eggs, but possibly larvae. Call an exterminator.

These are probably cockroach cases, or oothecae, that may contain up to 50 eggs, depending on species.

It looks like they are oothecaes of German cockroaches.
You can read more about baby cockroaches here.

I think these are cockroach oothecae. These are small casings that contain many eggs.

Quoting from wikipedia

Female cockroaches are sometimes seen carrying egg cases on the end of their abdomens; the German cockroach holds about 30 to 40 long, thin eggs in a case called an ootheca. She drops the capsule prior to hatching, though live births do occur in rare instances. The egg capsule may take more than five hours to lay and is initially bright white in color. The eggs are hatched from the combined pressure of the hatchlings gulping air. The hatchlings are initially bright white nymphs and continue inflating themselves with air, becoming harder and darker within about four hours. Their transient white stage while hatching and later while molting has led to claims of albino cockroaches.[22]Development from eggs to adults takes three to four months. Cockroaches live up to a year, and the female may produce up to eight egg cases in a lifetime; in favorable conditions, she can produce 300 to 400 offspring. Other species of cockroaches, however, can produce far more eggs; in some cases a female needs to be impregnated only once to be able to lay eggs for the rest of her life.[22

You can find more about their control here
Cockroach oothecae

perhaps it's a fly chrysalis. If you had a mouse that died, that would do it. put them in a jar and wait. https://www.insectes-net.fr/pieride/images/pier159gf.JPG


text:
Why does it hurt when water touches cuts?
Why do we feel a burning sensation when water touches cuts/wounds? People suggest applying oil over cuts while bathing to prevent water touching it, but water is heavier than oil so it shouldn't work, but it does, Why?

Water changes the local ionic concentrations and therefore induces an electric
signal at exposed neuron membranes.Oil is used to prevent entrance of water to the cut because it is hydrophobic i.e. repels water but attaches to the tissue.
Gravity plays no role here.

why does gravity play no role

@RamKeswani Presumably because the force of adhesion between the oil and the skin is stronger than gravity, as is the force of the oil repelling the water. I'm no physicist, but that makes sense to me... ;-)

Hi, welcome to Bio.SE! Please provide citations and appropriate forms of support for your answers. See our help page for further suggestions for writing good answers. Thanks!

It's a phenomenon called cutaneous hyperalgesia in which non-noxious stimulus like water cause pain. The Mechanism behind that phenomenon is the accumulation of pain-producing factors like (substance P), proteolytic enzymes, histamine or bradykinin which easily stimulate the nerve endings of the pain in the cut area. These substances are released from damaged cells. So the pain threshold is lowered. The non-painful stimuli become painful and the painful stimuli become exaggerated!
And sorry if I don't know about the oil and how it prevents that!

Hi, welcome to Bio.SE! Please provide citations and appropriate forms of support for your answers. See our help page for further suggestions for writing good answers. Thanks!

Your nerves withold a solution that has an electrical charge, when water enters a damaged nerve and nerve membrane, it changes the electrical balance in the nerve. Wounds are supposed to be treated with physical cleaning and topical antisceptic.
Here is a more scientific account:

Cells normally have a functioning
  ion pumps. Cells are surrounded by a membrane that acts as a wall with
  little holes that ions(sodium,chloride,potassium, calcium) can pass
  through with difficulty.  There pumps in functioning cells exchange of sodium, chloride and potassium.  This causes a
  difference in electrical potential across the cell membrane, in effect
  making the cell a battery. By exposing that tissue to water, which has
  no sodium or chloride, you immediately changed the concentrations of
  these ions surrounding these injured pain cells causing them all to
  fire at once.

Cleaning is normally water and soap or saline solution (9mg/L approx).
Non stinging antisceptics currently favored by doctors are Betadine, Merbromin, amonst others.
I like alcohol for reed cuts etc because it indicates when the exposed inner cell inside the cut and under the miasma have been well sterilized and attained.
https://www.quora.com/Why-do-wounds-hurt-more-when-they-get-wet

Soap and water (S&W) is fine. The dirtier the wound, the more S&W. No serious medical professional recommends Betadine and water for wounds. It's used in hospitals because it's there/easier to use than soap, but even there, that's changing. (E.g. We used to irrigate wounds with normal saline under pressure. Now we use a faucet/tap water and a non-stinging soap and water. Both Betadine and alcohol are harmful (to some degree) to living cells. And soap and water is better than alcohol, which no doctor in their right mind would use for fear of being punched - and hard - by the patient.

Biologists often disagree on facts. I'm surpised that using antisceptic on wounds is a controversial practice, considering it's more likely to stop infection than water based treatments. We probably only disagree on my poor wording.

@com.prehens.ible et al. please be nice to each other :) I am deleting most of this comment thread as this doesn't really seems to go anywhere. What I do know is that throwing youtube videos to a hardened veteran in healthcare won't really help. YouTube and Quora are no credible sources. I think anongoodnurse's issues arise mostly from the lack of references in your answer. If you guys prefer to have the thread migrated to chat, I'm happy to revive the comments and create a chat room. Cheers.