text:
What is this worm-like creature?
It is on my bed sheet. The hairy part the the rear end. The length is about the diameter of a US dime (~18mm).

I don't know about other uses but I am a bit bothered that so many US users are using their currency as unit of measurement. Please do not measure in US dime, US quarter, foot, banana or beer height but use the metric system!

@Remi.b - Americans don't know what the metric system is. Distance in feet, speed in miles per hour and fuel by the gallon ;-)

The other answer is most certainly incorrect. Silverfish are silver/grey and (like all members of the Zygentoma order) have three distinct, tail-like caudal appendages from their posterior end -- really, two large cerci with a central long filament.
 [Sources: 1, 2, 3].
The OP's specimen resembles the larva of a dermestid carpet beetle of some type; specifically, the location and appearance make me think it might be a black carpet beetle (Attagenus spp) -- for example A. unicolor.

 Source: Univ of California Master Gardener Program of Contra Costa County Blog
Description:
Tell-tale characteristic: the tuft of numerous "hairs" on the posterior end:

The larvae of the black carpet beetle, which may reach 12.7 mm in length, are very different from other carpet beetles’ larvae. They are elongate, carrot-shaped, golden to chocolate brown, and have a tuft of very long, curled, golden-brown hair at the tail end of their body.  [Source: Penn state Dept. of Entomology]

A description from IFAS suggests that larvae develop stiff, bristlelike tails when older.

See bugguide.net for more pictures, such as this one
Pest:
According to many of the sources I've linked to already, the larva is the damaging life stage of this beetle.

It's hard to tell from the image quality, but is it a silverfish? It has roughly the same body shape and size:

(source: umn.edu)


text:
What brazilian snake is this?
(1) Is it possible to identify the snake in the picture below?
If (1) cannot be answered:
(2) In view of the pattern of colors, is it possible the snake in the picture below be non-venomous? If so, what kind of non-venomous snake?
Additional informations:

Size: 62cm.
Region: South of Brazil, noutrh of Paraná.
I do not have a picture of the head.

Pictures:

The triangular pattern and the lightly colored underside resemble typical patterns of Bothrops (lancehead viper). Without the head it is quite difficult to tell which species this is. Given the location, the most common lancehead viper would be Bothrops jajaraca, simply called Jararaca by the locals.
Images can be found here

source: Stack Exchange

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

sort: votes


text:
Why ambidextrous persons are so rare?
According to this article, only about 1% of all humans are ambidextrous:

About 90 percent of people are right-handed, says Corballis. The
  remaining 10 percent are either left-handed or some degree of
  ambidextrous, though people with "true" ambidexterity—i.e., no
  dominant hand at all—only make up about 1 percent of the population.

Less dominance is observed in other animals, as indicated by this article:

Bill Hopkins, at the Yerkes Regional Primate Research Center in
  Atlanta, USA, has made even more contentious claims in recent years,
  asserting that his captive chimpanzees exhibit a 70% right-handed
  preference for many tasks requiring manual dexterity, a rate that
  rises to almost 98% for very specific tasks, like the precise over-arm
  throwing of objects. However, for everyday food-related tasks (like
  cracking nuts or digging out honey), the rate remains closer to 50-50.

I am wondering if there is any theory that explains why ambidextrous persons are so rare. As a totally layman when it comes to biology it seems that this would require a more complex brain to wire all the complexity to both members and this would be rarely justified (virtually all tasks can be done without being fully ambidextrous).
Question: Why are ambidextrous persons so rare?

Speculation: Left-right hemisphere competition and dominance became more pronounced as our brains evolved to do more and more cognitive work. Hand dominance increased as a side effect and there was never any selective pressure to maintain ambidexterity.

It would be interesting to know whether, and to what degree, it is simply a matter of training.  That is, once a child displays handedness, perhaps in early writing or ball games, it is encouraged to practice doing things with the dominant hand.  But from my own experience, when one temporarily loses the use of that hand (as with a broken wrist), it is possible to learn to do many things adequately well with the non-dominant hand.

While not specifically answering why ambidextrous persons are rare, one potential explanation is that mixed-handedness and/or ambidexterity seems to be related to adverse effects. For instance, some studies have shown that mixed-handedness (which might not be exactly the same as ambidextrous, depending on how you define the terms) is related to ADHD symptoms (e.g. Rodriguez et al. 2010) and patients with schizophrenia have an overrepresentation of mixed-handedness (Green et al, 1989; Orr et al, 1999) and ambidexterity (Crow et al, 1996).
A potential reason for the adverse effects seems to be that mixed-handedness and ambidexterity is related to delayed or weakened dominance of one cerebral hemisphere, which is important for language development (see e.g. Crow et al, 1996). See also this quote from Intelligence and the ‘Intelligence Quotient’ (Crow, 2001 from Encyclopedia of Genetics):

Handedness, reflecting cerebral dominance, is a trait that is associated with quantitative variation. Whether this variation is a correlate of human cognitive ability, as would seem plausible if it underlies the specific characteristic of language, has been much debated, but it now appears that lesser degrees of lateralization (‘hemispheric indecision’) are associated with delay in the development of verbal, and also nonverbal, ability (Crow et al., 1998). Thus it appears that lateralization is associated with significant variation in the rate at which words acquire meaning, and that this variation reflects a dimension that is specific to Homo sapiens.

This is not my area of expertice thought, and others more knowledgeable about the field can maybe expand on this or explain more in detail.

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


text:
What kind of weird little insect is this?
What kind of insect is this?
I found it in my work room.
I live in the city of São José dos Campos, São Paulo, Brazil

Please indicate the approximate size of your specimens. Also, if you have a clearer/brighter picture of the top of the insect, please provide that as well. Thanks.

This is probably a nymphal stage of a stink bug (aka shield bug).
Based on the roundness of your specimens, I'd suspect that they represent possibly the 1st or 2nd instar development stage.
I am unsure of the species currently, though I suspect this is an image of the adult (wrongfully labeled as a "bed bug" at its source):

 Source: Shutterstock
I will dig into the Brazilian fauna to see if I can get you a species...

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


text:
What are these creeping cacti tendrils?
During a trek through a small forest-type area on the main island of Hawaii, I came across the following plant:

It did not cover very much area from what I could tell (there was a continuation of the bed just behind me from where I took the picture). I believe it was near Punalu'u Beach but I can't say with certainty.
It's creepy, looks like a tractor load of snakes got loose, and something I find fascinating. Could someone tell me what this cactus-y, bed of vines-like plant is?

I don't know what plant this is (a closer picture would help) but I was surprised on a recent trip to Maui by the large number of large cactus invasions. Mostly central american jungle species, but some prickly pears too. Really unfortunate. Don't get me wrong, I like cactus, they just don't belong in Hawaii, in my opinion.

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


text:
What are these lines that connect into cells called?
I just recently watched a very interesting video that showed cell division under a microscope. In the video, you can see cells that have either one, two or more lines connected to them. What are these called?
Source: https://youtu.be/rgLJrvoX_qo

It's not clear to me to which lines you are referring to.

I added a photo and I apologize for the confusion. You can see multiple strands going off from each cell in photo.

I think it's likely they are filopodia; however, without knowing more background on the image and what cells we are looking at and under what conditions I'd leave that as just a hesitant guess.

@Bryan Krause I believe you are correct and thank you so much. I am reading into what exactly this Filopodia is and what it does. Thanks for sharing something new with me I love to learn. I don't know how to upvote but just wanted to say thank you.


text:
I found this on the beach at Breamlea in Vic Australia and wondered if you could tell me what it is please
It is about 6.5 x 5 centimetres and semi transparent.
It has quite a tough skin and is hollow inside. Like a tight clear tooth shaped balloon. I have put a coin next to it for you to see the size.

Dentist merchandise?

It's a swim bladder, probably a porcupinefish swim bladder. They can be found washed ashore still inflated. They've been described as "molar shaped". (Picture from Australian Museum.)

It's hard to tell exactly, but if I had to bet I'd say it's a small part of an algae called Neptune's necklace:

Some species are native to New Zealand and Australia. Where two "branches" split, the shape you found can be produced.
Looks like they're also found in your area: http://bie.ala.org.au/species/NZOR-4-7414


text:
Is resource partitioning a type of character displacement?
Question
Imagine two related species. They prey on the same species but avoid competition by feeding at different times of the day. Is this a type of character displacement?
Thought
On one hand I have the  Galapagos Finch example, which is typically used to illustrate character displacement. But since resource partitioning is more behavioral than anatomical, is resource partitioning a subset of character displacement or a rough overlap or none?

Welcome to Biology.SE. Is this a homework question? What are you thoughts on the question? My answer is ready, however we have a policy of not answer homework question (or homework-like question) without the OP showing an attempt at answering his/her own question. So I'm just waiting for you to explain your thought process. You can click on edit, to edit your post and add this info

Edited. It is no homework. Just a question that sprouted in my head

@Bakshi please provide evidence that you tried answering this question yourself to avoid having the question closed. Thanks!

Does it look like character displacement?
By the fact that these two species feed at different moment of the day, they therefore have slightly different ecological niches. It is indeed the type of consequences brought about by character displacement. Yes, it looks like character displacement.
"Resource partitioning" is not necessarily more behavioural than anatomical and even if it was, a behaviour is a phenotype, just like any other phenotype, and it should not be disregarded. The character being displaced in a 'character displacement' scenario can be behavioural. So, yes if two species evolve to prey at different time of the day to avoid competition, then they have evolved so as to reduce the overlap between their ecological niche and we can call that character displacement.
Is it character displacement (highlight on a few missing information)?
It is possible (likely) that they evolved to feed at different times as a reaction of their competition and hence it would be called "character displacement" but technically speaking the question does not explain how these two species had been diverging in their feeding. It is possible that divergence in their feeding time happened long before being found in sympatry. In fact, the question does not even make clear that the two species are found in sympatry.


text:
Wood-eating bug in Germany
This bug was found in an old church in Southern Germany. Apparently it was damaging/eating wood. A local woodworker could not identify the bug and speculated that it was some foreign species.
Unfortunately I only have these blurry pictures, but I figured that it is worth a shot.

UPDATE: A specialist who was consulted by the church where the bug was found believed the bug to be Lyctus brunneus (brown powderpost beetle), but did not provide rationale.

It is usually the larvae of beetles that are the wood damaging ones, not to say there aren't beetles that might chew on wood, but the ones that do don't tend to cause a lot of damage.


text:
Required energy to metabolize fat
Tl;dr: What is the net joule value of fat if used for energy provision, compared to e.g. carbohydrates. So does 1 Joule Fat intake result in 1 - X Joule energy provided to the cell, or does it work in a completely different way?

My understanding is that if I take in one Joule of fat, my body takes in the energy to move ~100g of mass up by one meter (Wikipedia).
Now for my body to use that energy, it needs to convert it to some sort of Glucose, right?
From the Lipid Metabolism Wikipedia Article I get that my fat needs to become a Triglyceride to serve as energy source.
There are some steps involved, roughly the following:

gastric peristalsis (basically muscle contractions to mix it all up)
peristaltic contractions in the gut (again, mixing is key)
lipase, also working in the gut to finally create Triglyceride
then the fat gets "packaged" in Chylomicrons and put into the bloodstream

releasing energy to the cell involves the following

Lipase unpacking the Chylomicrons
Splitting of the Triglyceride in Glycerin (the stuff we want) and fatty acids

Now this seems like a really cumbersome process to me, and I wonder what the net Joule Value is that arrives at the cell.
Is it significant, or is this process so efficient that it doesn't matter anyways?

@Gyro Gearloose: Okay, that makes perfect sense. As soon as I am home I will try to rephrase the question more specific. I have never had any deeper chemical / biological education, just starting to get an overview over the terminologies...

I'm not so sure about the balance, but you need some heat to function. Fat might generate a bit more "waste" heat, leaving less to use for mechanical purposes, but perhaps glucose is so efficient you actually just need to burn a bit of it to keep warm. Also keep in mind that also the digestion of glucose needs several of the steps you mention, and nutritional energy content is the chemical energy content with some correction factors, perhaps already including the factors you mention.

So, what I was looking for, but was lacking the knowledge of, was the concept of "Thermic Effect of Food"
I really didn't know how to phrase my question well, due to the fact that I tackled the problem from the wrong angle.
Direct quote from the Wikipedia Article as it answers the question best:

The thermic effect of food is the energy required for digestion, absorption, and disposal of ingested nutrients. >Its magnitude depends on the composition of the food consumed:
Carbohydrates: 5 to 15% of the energy consumed [7]
Protein: 20 to 35% [7]
Fats: at most 5 to 15 %[8]


text:
Are 'homeothermic' and 'endothermic' synonymous?
I got this question from the comments below this answer. So, do homeothermic and poikilothermic have the same meaning as endothermic and ectothermic, respectively?
 A user also suggested that the terms such as poikilothermic and homeothermic have become obsolete. What is the reason for them being obsolete?

[D]o homeothermic and poikilothermic have the same meaning as endothermic and ectothermic respectively[?]

No. Once you are referring to the source of the heat, while the other time you are referring to whether the internal temperature varies through time.
Source of heat

endo = inside
exo = outside

Variance in internal temperature

Poikilo = varies
homeo = does not vary

Combinations
Any combination of these two axes exist. For example: If the temperature in the environment never varies you can be homeotherm without needing to be endotherm. You, for example, are a homeo-endo-therm.
A fun common example are the large dinosaurs that are thought to be homeotherms (but see @John's and @Gerardo's comments) because their metabolism produce some heat as by-product (just like any organism) and they are so large that they remain warm thanks to this heat source. However, they were probably not able to regulate actively their temperature. Therefore, I would tend to qualify dinosaurs as homeo-exo-therm but I wouldn't be surprised if someone prefers to call large dinosaurs homeo-endo-therm.
Note that the terminology might be a bit more complicated in reality as the diversity of mechanisms of body temperature regulation is important.

The whole mass-homeothermy thing tends to only pop up from people who don't understand dinosaur anatomy, larger dinosaurs are not going retain significantly more heat than elephant sized dinosaurs, and no one would argue elephants are homeoectotherms.  Long necks, long tails and  widespread air sacs provide gigantic heat exchange surfaces.


text:
What species of snake found in central Alabama, US?
The snake in the image below was found in the attic of a home in a relatively well-forested suburb of central Alabama, south of Birmingham about 20 minutes. It was safely released outside in the wooded backyard area. What species is the snake in the image below?
Some additional details that may be helpful follow. It emitted musk while being coaxed into the box. I don't recall seeing much striping, except near its head, as can be seen in the image below. I did not get a good look at the belly color, but I believe from the glimpses I got that it was similar to the lighter color on its back and sides. It appeared to be close to 3 feet (~90 cm) long.
I attempted to use Google to identify the snake, and the closest matches were various rat snakes. None had quite the same patterning.

Definitely looks like some species of rat snake (genus Pantherophis). Based on the size, location and coloration, I'd say it's a dark variant of a Gray rat snake (Pantherophis spiloides).

It might also be a cross between a black and grey rat snake (i.e., Pantherophis spiloides x obsoletus).

 Source: Todd Pierson

 Sources: Alan Brumbeloe | Bill Funderburk
Description: Adults usually 99-183 cm long; dark to light gray with darker gray or brown blotches

Unlike other Pantherophis, whose conspicuous juvenile pattern fades into adulthood, gray ratsnakes do not undergo drastic ontogenetic changes in color or markings. These snakes retain the juvenile pattern of dark elongate dorsal blotches separated by four, or more, pale gray body scales, a light gray crown with dark striping that forms an anteriorly facing spearpoint, and a solid band which covers the eyes and extends rearward to the posterior upper labial scales. The venter is usually off-white or pale gray with darker irregular blotches, and a double row of black spots behind the divided anal plate of the vent. The dorsal scale rows around midbody are usually weakly keeled. Because the gray ratsnake shares its range with other members of its genus, hybrids of midlands x eastern ratsnakes are not uncommon. [Source].

Note, According to here one could have a difficult time IDing juveniles between species of rat snakes:

The juveniles of all subspecies [of rat snakes] resemble the gray rat.

However, your specimen's size indicates it's likely an adult, and therefore its strong patterns preclude the black rat snake.

Distribution:  commonly found in the forests of eastern and central United States, including throughout Alabama:

 Source: Trey Dunn
Behavior: Gray ratsnakes are agile climbers and can be found in tree tops as well as barns/sheds/buildings close to forests

The gray ratsnake will defend itself by raising its head and bluffing a strike. If handled, these snakes will musk a victim by releasing the foul-smelling contents of their cloaca, and will bite if necessary. [Source].

It looks like a gulf hammock rat snake. Beloved to be a subspecies that started as a cross between yellow rat snake and grey rat snake. I know they occur in northeast Florida perhaps they are in Alabama as well.

We expect answers on species ID questions to be more than just an unsupported guess; it's best to use references from reliable sources to support an ID, and explain how that ID was reached to the exclusion of other possibilities.


text:
Identifying a beetle from northern California
Just found this organism crawling across my wall on the second story at around 12:30 AM. We're in Sonoma County in California. Our best guess so far is a soldier beetle, but the coloration doesn't seem to match any images we can find online. It's body was about 1.5 inches long and was a uniform brownish-tan color with black eyes. It may be worth noting we're in the middle of the worst heat wave we've seen in 15 years of living here.

This is a long-horned beetle, family Cerambycidae; the site http://www.sbcollections.org/cbp/DB_Query.aspx?Field=family&Value=Cerambycidae has a list of California species, with links to pages on each species (there are 387; not all species pages feature illustrations -- those that do figure museum specimens).  From that list the first that resembled your photograph is that covering Centrodera spurca (LeConte 1856), which has been found in Sonoma County; given that I haven't gone through the entire list there are likely other possibilities.
Centrodera spurca

I agree it's a long-horned beetle (so +1) but a picture to compare it to would be helpful. I edited to add. Not sure if it's the same beetle, though. They look like they can easily be mistaken within the group.


text:
Why do ostriches have wings?
Wings serve most birds for flying, or (as in penguins) for swimming. But ostriches, which exclusively use only their legs for locomotion, still have wings. Why?

Watch Planet Earth II - Grasslands. There is apparently a funny use for those wings :)

Related: Why don't mammals have more than 4 limbs?.

They are vestigial structures.
Vestigiality refers to genetically determined structures or attributes that have lost some or all of their ancestral function in a given species, but have been retained during the process of evolution.

The emergence of vestigiality occurs by normal evolutionary processes, typically by loss of function of a feature that is no longer subject to positive selection pressures when it loses its value in a changing environment. The feature may be selected against more urgently when its function becomes definitively harmful. Typical examples of both types occur in the loss of flying capability in island-dwelling species.

In the case of an ostrich,  its ancestors used wings to fly,  but the  development of  faster running abilities,  keener eyesight and a paucity of capable predators allowed the bird to  no longer receive positive selective pressure  to have " functional"   wings.
It's late.  I'll add more detail in the am.

I am not sure vestigial is the correct term in this case. Since the wings have acquired (or never lost) another function during male display. Furthermore I think they help balance while running.

@have fun : I thought about that, but really vestigiality can be used in instances in which an organism's feature has lost "SOME or all" of its "ancestral function." In this case, the ostrich has lost SOME of its wing functionality (flying). So I think vestigiality still applies.

Why not?
Since the wing on a ostrich does not harm the animal, there is no selection pressure to remove it from  the population. And male ostriches do use their wings for mating displays. So it isn't completely without use.

Or to put it a bit differently, ostriches with wings the size they are are not at a competitive disadvantage to those with smaller (or larger) wings, so when/if random size changes happen, there's no preferential selection.  At least not in the time span we can look at: it's possible that if we came back in a few million years, ostrich descendants would have smaller wings, or they might not be visible at all.  (Though the genes might be there, like the "sonic hedgehog" gene in snakes: http://news.nationalgeographic.com/2016/10/snakes-grow-legs-evolution/snakes-grow-legs-evolution/ )


text:
ID bug found in Mojave county, USA

What is this? I found it under a bed sheet. I live In Mojave county, AZ, USA, in the middle of the desert. It was probably 1/8 inch long. And narrow.

Initial guess based on mouthparts, coloration and small size:
Neuropteran larva. Possibly a green lacewing (family Chrysopidae).
See:

 Source: Bugguide.net

 Source: Cedar Creek Ecosystem Science Reserve
According to here, green lacewings are found in Arizona deserts.
I will update in the morning with more detail...


text:
Why is there a weevil on top of a beetle?
A click beetle was walking around and there is a weevil on top of it.
Any idea why? I would also like to know the exact species of these insects.
 !
Time: 18:50, place: Netherlands / Noord-Hollands / Overveen / the Amsterdamse waterleiding duinen / it's in the dunes near forest and grasslands near the dunes

Where and when was the picture taken?

That's probably a small male mating with a big female. Like in this photo: https://www.naturepl.com/stock-photo-dor-beetle-geotrupes-stercorarius-smaller-male-riding-on-back-of-image01585111.html

@personjerry No, they are completely different species from different families; Curculionidae and Elateridae it seems.

Just to be clear; for species-ID questions we consider them off-topic (Too broad) if they do not contain time and location (and preferably the environment and circumstances for the observation).

Time: 18:50, place: Netherlands / Noord-Hollands / Overveen / the Amsterdamse waterleiding duinen / it's in the dunes near forest and grasslands near the dunes. Thanks for the family names! I just really wonder why the click beetle was giving a "beetle ride" to the weevil. I thought that maybe the weevil was sucking out the beetle, but weevils only suck on trees right?


text:
Is this a Zelus luridus?

I found this little bug on my bed and I got curious to know what it was, I did some researches and then I noticed that it is very similar to Zelus Nymph but I can't be sure of it. Can you confirm it?
Here is a processed version of the image:

I'm sorry to say we still need a better picture; the focus (or rather lack thereof) makes any identification suspect (though looking at the front pair of legs as-is makes me suspect that any Assassin Bug identification is likely wrong).

Ok, thank you for the comment. If I can I'm taking a better picture.


text:
Larva of Halyomorpha halys?
I just found these small insects on a Saponaria.
After search, it could be Halyomorpha halys, but I am really not sure.

Can anyone confirm? If so, should I kill them as they are considered as agricultural pest?
They are about 3-5mm. I am living in the south of Paris (48.814766, 2.334659)

This is an instar (nymph) of a shield or stink  bug (order Hemiptera, family [Pentatomidae])(https://en.wikipedia.org/wiki/Pentatomidae).
This appears to be similar to the 2nd (or possibly 3rd) instar of Halyomorpha halys.

European and Mediterranean Plant Protection Organization; Credit: Matteo Maspero
UTIA suggests the 2nd instar begins to develop an almost black appearance, where that blackness gradually shifts to browner shades in subsequent instars. According to Medal et al. (2013)1 the 2nd and 3rd instars have median lengths of ~2.75 and ~4.25 mm, respectively. According to WSU Extension, instar nymphs of H. halys are spiny (including on the shoulders) and possess light bands on the antennae.

 Source: WSU Extension
This University of Wisconsin Extension site provides a fairly similar photo to your specimens, which can be found at bugguide.com:

 Source: bugguide.com; Credit: Yurika Alexander

 Citations
1  Medal, J., Smith, T. and Santa Cruz, A., 2013. Biology of the brown marmorated stink bug Halyomorpha halys (Heteroptera: Pentatomidae) in the laboratory. Florida Entomologist, 96(3): 1209-1213. PDF


text:
How do some deep sea creatures lower their metabolism to stay alive for a long time?
I was watching some bio related videos and saw in one that some deep sea creatures  and other organisms purposefully limit their movement to decrease metabolism rates. Do they live longer?
If we apply this same theory to humans, doesn't it mean that exercising less and regulation of diet may help decrease metabolic rates? I know exercise is extremely good for the body but this just got me thinking...


text:
Olympic's epidemiological impact on Zika?
I've seen a lot of fear mongering, misinformation and overall general panic concerning the zika virus surrounding the Rio Olympics. However, little has been said about the actual epidemiological impact of these Olympics concerning zika.
I would assume that sending hundreds of thousands of people into this 'zika hotspot' and then having them return to their home countries will likely only accelerate the spread of this virus. I understand that Zika has been present in other tropical parts of the world for 50+ years, but the South American strain has had a higher incidence of more dire effects.
My question:
Has anyone actually modeled how these 2016 Olympics will impact (likely accelerate) the spread of this dangerous viral strain throughout the world?
I know the CDC and WHO have people working on this, but I haven't seen any direct reports or evidence of such work. I know it's difficult to create too accurate of a model due to the lack of knowledge about other mosquito species' abilities to become carriers, so I would assume that if a model does exist, it's likely just using Aedes species as the main vector.
Regardless, if anyone knows about epidemiological modeling being done about the Olympic's impact on the spread of zika, please provide some resources.

Though I have not found direct access to a model (which is what I'm really looking for), I have found evidence of such modeling efforts.
The CDC apparently put out a risk-assessment report in mid July discussing the results of such epidemiological modeling (reported by FivethirtyEight, ABC and others).
The report (available here), suggests that the risk of accelerated zika spread due to the 2016 Olympics is low.
They cite two major reasons:

Low mosquito activity due to colder winter weather

and more importantly....

The number of increased visits to the Olympics will make up only a fraction of the number of people that travel to/from zika-affected countries on a regular basis.

The estimated 350,000 to 500,000 international visitors and athletes
  from 207 countries who are expected to travel to Rio de Janeiro for
  the 2016 Olympic and Paralympic Games represent a tiny fraction --
  0.25 percent -- of total travel to and from Zika-affected countries,   according to the CDC report.

According to CDC director Tom Frieden:

"Compared with all travel to Zika-endemic areas, the Olympics account
  for about one-tenth of 1 percent of travel from the U.S. and globally
  about one-quarter of 1 percent, so even if Olympics didn’t exist,
  99.75 percent would be the same risk."

I will contact the CDC directly and ask for additional information regarding the model they used for this report. I will update this answer with any additional information I can gather. However, I'm sure others are producing similar models using different criteria, so please feel free to add additional examples or provide direct links to any available models.


text:
Mushroom Identification: Brown gilled mushroom in Ohio lawn near rotting stump roots
Even though I ID a lot on this site, I'm rather unqualified to ID mushrooms (even with the help of sites like urbanmushrooms.com).
Can anyone help me ID this mushroom species?

Attributes:

Morphology: convex cap; gills possibly free, adnexed, or sinuate (I really can't tell!); stem is equal or slightly club-shaped
Color: Brown cap; white gills; white/brown stalk
Size: 1.5-2.5 inches tall; cap 0.25-1 inch diameter
Other sensory: cap texture is smooth/waxy similar to white button mushroom one buys in a grocery store; smell is minimal but perhaps slightly musty?
Location: Eastern Ohio (Ohio Valley, about 10 miles West of the Ohio River)
Habitat: growing in recently moist (though almost dry) grass near (but not on) a rotting stump.  Violets, clovers, and other herby weeds also growing in lawn nearby.
Timing: Mid July; found on a sunny day after a week of on-and-off rain

More photos (click to enlarge):

You will need a spore print ; put a cap on newsprint in an undisturbed location for a day or so. The newsprint gives both a white and black background reference.

@blacksmith37 already in that process... waiting [not so] patiently

those mushrooms grow a lot near me.

I was advised by Walt Sturgeon, author of Appalachian Mushroom: a Field Guide as well as members of Poisons Help; Emergency Identification For Mushrooms & Plants Facebook group that this is likely Marasmiellus luxurians.

 Credit: Walt Sturgeon 2018 | Source: Mushroomobserver.org
Mushroomexpert.org provides the following supportive pieces of info:

Ecology matches: "growing gregariously or in tight clusters in woodchips, or on lawns (probably fruiting from dead, buried roots), and, rarely, fruiting directly from logs and stumps; summer and fall."

Location matches: "widely distributed and relatively common east of the Great Plains".

Walt Sturgeon suggested the following when I asked him about comparing this to similar-looking Entoloma:

Marasmiellus has a white to buff spore print.  Entoloma spores are ruddy pink.  A spore print is made by removing the stem and place the mushroom gill side down on white paper. cover with a bowl. wait several hours and there should be a spore deposit on the paper.

My spore prints did appear to be white.


text:
Is the genetic term "polycistronic" still used in modern biology?
Is the term "cistronic", meaning an ORF on a mRNA, still commonly used in modern genetics? I´ve seen "polycistronic" being applied to prokaryotic mRNA in old textbooks, but I´ve rarely stumbled upon this in recent papers, except for research focusing on plasmid engineering.

The thing that I think biologically interesting about this question has perhaps not been emphasized sufficiently in the answers so far which document that the term is still in use. This is why the term is still in use. As the poster states:

I’ve seen “polycistronic” being applied to prokaryotic mRNA in old textbooks, but I’ve rarely stumbled upon this in recent papers

The reason to expect that it would have fallen out of use is:

The shift in research from prokaryotes to eukaryotes in the last 40 years or so
The initial impression that all eukaryotic mRNAs were monocistronic.

It is the discovery of, and the interest in, exceptions* to the latter that has, in my opinion, kept the term in use. There are dicistronic and polycistronic mRNAs in eukaryotes (not just their viruses).
This is illustrated by the first two references in the answer from @theforestecologist, which refer specifically to eukaryotes in their titles.
*Footnote
The exceptions vary with species, but, to take an example that puts things into perspective, of almost 14,000 protein-coding genes in Drosophila there are only about 70 for which polycistronic mRNAs (usually dicistronic) have been established. See the p. D811 of the paper on FlyAtlas 2 and supplementary Table S6. It’s not too surprising that authors of basic text books choose to focus on generalities in an attempt to explain the main ideas in a complex subject.

Yes, it's still used.
If you search Pubmed for "polycistronic", it offers you a chart showing the counts of the term by year (top right). Downloading the CSV and making a chart shows that it's never been a very common term, but it's still used. I suspect, but don't have time to check, that if you were to divide the use of the term by the number of published papers by year its use-per-paper would be pretty much a flat line.
Edit, re-reading the question, it may be about "cistronic" as opposed to "polycistronic". "Cistronic" is also still used, but not nearly as often as "polycistronic" -- 13 times in 2018 to "polycistronic's" 81.

@iayork's answer provides a great approach to examining this question. I just want to corroborate it by using a slightly different approach.
A Google Scholar search for "polycistronic" limited to results since 2015 provides >200 hits.
Some examples include:

Gordon, S.P., Tseng, E., Salamov, A., Zhang, J., Meng, X., Zhao, Z., Kang, D., Underwood, J., Grigoriev, I.V., Figueroa, M. and Schilling, J.S., 2015. Widespread polycistronic transcripts in fungi revealed by single-molecule mRNA sequencing. PloS one, 10(7), p.e0132628.
Karginov, T.A., Pastor, D.P.H., Semler, B.L. and Gomez, C.M., 2017. Mammalian polycistronic mRNAs and disease. Trends in Genetics, 33(2), pp.129-142.
Liu, Z., Chen, O., Wall, J.B.J., Zheng, M., Zhou, Y., Wang, L., Vaseghi, H.R., Qian, L. and Liu, J., 2017. Systematic comparison of 2A peptides for cloning multi-genes in a polycistronic vector. Scientific reports, 7(1), p.2193.


text:
What is the name of this little plant?

It was found in Malaysia in my school compound.

Looks like something in the mint family.  Does it have an odor?


text:
What type of skull is this?
This skull was found in the mountains/woods of extreme southwestern Virginia (Dickenson County). There is not (to my limited knowledge) any animal native to this area that has this type of skull. Anyone have any idea what it could be? Sorry, no teeth or lower jaw were found. The backbone seems to come directly out from the back of the skull and the nose/beak/front area seems to be flared on the sides.

It's a bird synsacrum rather than a skull. See http://biology.stackexchange.com/questions/20089/what-kind-of-skull-is-this Based on size and location, probably a turkey.


text:
What are these semi transparent pill-shaped things in the Mediterranean Sea?
I was swimming with gopro in Sardinia, Le Bombarde beach in early November and today was reviewing footage - I noticed that water is full of semitransparent whitish "pills", see pictures below.
Any idea what that is, is it seasonal, has any implications to people taking a swim?
Jellyfish nearby should give approx idea of the size, seems something like 1-2cm long.

Quick guess based on your low-quality photo:
Reminds me of a pyrosome, a tube/rod-shaped, free floating colonial tunicate.
According to here, Pyrosoma atlanticum is the only species found in the Mediterranean.

 Image Credit: amutti; Source: inatrualist

 Image Credit: Megan Mariposa; Source: inatrualist
See iNaturalist,National Geographic and Project Noah for images of similar body shapes.

Unbelievable! Can you earn the ID badge twice?

@anongoodnurse :p. thanks! I should go earn it on Outdoors.SE ha! ;)


text:
What insect would make a hole and lay eggs in it
Does anyone here have an idea what insect would make a 1-2mm hole in a grape vine cane, and lay small white/clear eggs?

Holes in cane:

What's your location?


text:
Reaction of the body to heat
In massage school we are being taught hydrotherapy -- applying cold and heat to specific areas.
It says that when applying cold, first the body goes through vasoconstriction, and then later vasodialation. That makes sense -- preserve heat through the former, but if the cold is applied for too long the body still has to keep the cells alive, thus the latter.
What doesn't make sense is this passage, in relation to applying heat:

Law of Action and Reaction: Initially blood will rise to the
  surface, applied for too long the blood will recede to the interior
  causing inner congestion to be greater than before

Is that true?

Local warming of a patch of skin will cause vasodilation. However, after prolonged warming there is a 'die away' phenomenon, is which blood vessels slowly constrict back to their normal diameter.

Johnson JM, Kellogg DL Jr. Local thermal control of the human
  cutaneous circulation. J Appl Physiol (1985). 2010;109(4):1229–1238.
  doi:10.1152/japplphysiol.00407.2010
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2963328/

You are right, it doesn’t make sense. No matter what, the inner organs have to function at some level, producing heat which the body has to transfer to the surroundings, otherwise the inner temperature will rise. The main physiological mechanisms for losing heat are to increase the blood flow to the skin (vasodilation) and sweating (evaporation). And the body will try to use these mechanisms, no matter how futile it may be in a high-temperature/high-humidity environment.
Actually, neither does the suggested responses in low temperature make much sense. Again, the body has to preserve its inner temperature, this time by reducing the blood/heat-transfer to the skin (vasoconstriction), shivering and raising the feathers or fur. Maintaining the core temperature is paramount, and eventually, the skin and extremities will be sacrificed if needed. Numerous examples can be found!
There is however a small amount of truth in the hypothermic response: people adapted to cold environments can control bloodstream to different extremities (fingers or feet), avoiding frost-bites or for dumping excess body heat after heavy exercise, avoiding to sweat all over the body (Ref.: Schmidt-Nielsen, Animal physiology adaptation and environment, Cambridge University Press 1990).

Welcome to Biology.SE! We prefer answers that are supported by references. Can you [edit] your answer to include references?


text:
What are these tiny creatures swimming around my aquarium?
I was checking out my aquarium today, and decided to scoop out a water sample and take a look at it more closely. What I discovered were numerous, very, very tiny white worms (?) swimming around in the water.
The worms hover around 1 mm or smaller, almost invisible to the naked eye, with some exceptional specimens reaching nearly 2 mm in length. They swim very fluently, not by wiggling or waving their bodies around, but simply, effortlessly gliding through the water.
I checked them out under a microscope, and recorded some videos. I apologize in advance for the lackluster quality, as I'm not working with expensive equipment here. It took me hours to locate the worms under the microscope, made no easier by how surprisingly fast they are.
Here's a picture:

When I first saw this, I wasn't sure I was looking at the right thing. As you can see in this video, it appears to stay rooted at the tail, while wiggling its head (?) around in various directions. Its most notable characteristic is the two ball-like structures on the front of its body. I have a feeling that those structures will be key here.
This next part was very poorly recorded, but boy did it surprise me when I saw it. Eventually, the worm stretched forward, its head seemingly morphing into three parts (video):

Finally, here's one more clip showing off how fast they can be when they want to (I swear it's not even sped up!). I wasn't able to get it back under the microscope at this point.
Does anyone know what these are, or at least what kinds of worms they might be related to (with respect to the ball-like structures on its head)?
For a little extra background, I found these in my native tank sourced with creatures caught in southern Alberta. The tank contains some longnose dace, which have been a source of concern due to heavy flashing (scratching) ever since I caught them. It makes me wonder if these worms are related, such as some kind of parasite. I'm happy to have them if they're some harmless detritus worm-- any members of the cleanup crew are welcome-- but if they're something to be worried about, I'd prefer to know.

this time I can help you ID these :). I'm now reminded, though, that I never figured out your fluke question. I'll have to go back and take a look...

Hard to tell because of the poor picture/video quality, but almost immediately the body shape, distinct "face", size and behavior made me think of a small invertebrate animal called a rotifer (Phylum Rotifera).

 Rotifer eating protists. Photo Credit: Jacqueline Ronson, 2016
There are about 2000 species occurring worldwide within this primarily freshwater phylum, each of which is fairly simple anatomically. Their name (which means "wheel bearer") comes from the two crowns of quick-moving cilia they possess on their heads:

 Source: Gifer
These cilia attempt to push food posteriorly toward the rotifer's back-set "mouth" (which is actually a modified pharynx called a mastax:

 Photo Credit: Jean-Marie Cavanihac
Rotifers are small (always < 2 mm) and so eat small planktonic and protist prey. From UC Berkeley:

As rotifers are microscopic animals, their diet must consist of matter small enough to fit through their tiny mouths during filter feeding. Rotifers are primarily omnivorous, but some species have been known to be cannibalistic. The diet of rotifers most commonly consists of dead or decomposing organic materials, as well as unicellular algae and other phytoplankton that are primary producers in aquatic communities.

As for body shape:
Although all Rotifer species are bilateral animals, they vary quite a bit in body shape. Box-like shaped rotifers are referred to as being loricate, while more flexible worm-shaped species are considered to be illoricate.

 Photo Credit: Juan Carlos Fonseca Mata
Regarding sometimes staying "rooted at the tail" as the OP observed:
Some rotifers are found usually free-swimming, while others "glue" down their posterior "toes" to anchor themselves to some substrate or debris. Again from UC Berkeley:

The final region of the rotifer body is the foot; this foot ends in a "toe" containing a cement gland with which the rotifer may attach itself to objects in the water and sift food at its leisure.

 Source: Starr et al. 2013 (Cengage Learning)
See here for further "fun facts!"

The "crowns of quick-moving cilia" convinced me beyond a doubt that you are correct; they appeared to be moving exactly as depicted in that GIF. I'm relieved to read that they're harmless, and even beneficial.

@560812508, rotifers may be harmless, but that many of them in your aquarium indicate lots of even smaller organisms are present for them to eat. You might want to consider changing the water more often or adding a biofilter.


text:
Can anyone tell me what type of fish this is?
Notice the reflective patterns on its underside.  I think it must be a deep water fish.  It was found washed up on the ocean sand in Myrtle Beach, South Carolina (USA) after a hurricane.

Not an expert, but an online search for bioluminscent fish led me to a bioluminescent toadfish called Porichthys porosissimus. The ventral angle of your specimen looks a lot like the photos I could find...

 Source: Robertson, R on Fishbase
Like many midshipman fish, P. porosissimus have photophores (those dots in your specimen) that glow to attract prey:

 Source: W. Ward (Rutgers Center for Research and Education in Bioluminescence and Biotechnology)

This site provides a sightings map, but some of the points are sort of suspect, so I don't know how accurate it is...


text:
Why is wombat scat (feces) shaped like cubes?
I've heard that wombat scat is cube shaped, but I don't understand how that can happen. Has anyone studied the phenomenon? What would the evolutionary pressure have been to cause this?

How do wombats poop cubes? Scientists get to the bottom of the mystery

Although the OP might no longer be active, I'm comming back to this question, because there is a new study on this released in "Soft Matter". With simulations Yang et al., 2021, describe how corners of these almost perfect cubes might be formed. From the abstract:

Using histology and tensile testing, we discover that the
cross-section of the intestine exhibits regions with a two-fold
increase in thickness and a four-fold increase in stiffness, which we
hypothesize facilitates the formation of corners by contractions of
the intestine. Using a mathematical model, we simulate a series of
azimuthal contractions of a damped elastic ring composed of
alternating stiff and soft regions. Increased stiffness ratio and
higher Reynolds number yield shapes that are more square. The corners
arise from faster contraction in the stiff regions and relatively
slower movement in the center of the soft regions.

As described by the previous answer, there are apperently two stiffer regions opposite of each other in the last intestinal section, seen in the longitudinal direction. These press inward more strongly during intestinal peristalsis, i.e., repeated contraction, thus flattening the material further and further on opposite sides, so to speak.
Similarly, we form a cube from a spherical piece of plasticine by pressing inward with two parallel fingers on each side, doing so sequentially from different sides. In the wombat intestine, however, there is no change in the direction of indentation, so the researchers assume that the more elastic intestinal strips are pulled inward in the middle and in this way flatten the missing sides.
As @anudder already pointed out, the last author commented on this in "Science": How do wombats poop cubes? Scientists get to the bottom of the mystery

The stiffer portions are “like a stiff rubber band—[they’re] going to
contract faster than the soft regions,” says David Hu, a biomechanics
researcher at the Georgia Institute of Technology and author on the
study. Softer intestinal regions squeeze slowly and mold the final
corners of the cube, the team found. In other mammals, the wavelike
peristalsis of the intestinal muscles are consistent in all
directions. But in the wombat, the grooved tissue and the irregular
contractions over many cycles shape firm, flat-sided cubes.

Why?
It is not yet proven, but they suspect that it has a purely practical reason. Like many other animals, wombats mark their territory with excrement. They often choose stones as a place to lay their excrement, from which cube-shaped piles roll down and away less easily than round specimens would.

I'm almost certain that your question is based on the press that Patricia J Yang's research is receiving (e.g., here and here).
Yang and her co-authors examined the structure and mechanics of some dead wombats to investigate this question further. They found that varying degrees of pressure in the latter portion of the wombat's intestines (in conjunction with a dehydrating of the fecal matter) led to the characteristic cube shape:
From their abstract:

In the final 8 percent of the intestine, feces changed from a liquid-like state into a solid state composed of separated cubes of length 2 cm. This shape change was due to the azimuthally varying elastic properties of the intestinal wall. By emptying the intestine and inflating it with a long balloon, we found that the local strain varies from 20 percent at the cube's corners to 75 percent at its edges. Thus, the intestine stretches preferentially at the walls to facilitate cube formation.

Why do this?
There seems to be two major reasons:

Mark territory
Attract mates

For example, see Wells 19891:

The rubbing of posts, logs and overhanging branches with their backs and rumps and deposition of faeces along trails may be a means of olfactory communication used in the maintenance of territories

One hypothesis is that by being square, the droppings don't roll as easily and therefore stay in the place that the wombat intended to mark.
I've also seen hypotheses about wombats stacking their square feces as some sort of signaling, but I couldn't find any reputable literature sources that make this suggestion.

1: Wells, R.T., 1989. Vombatidae. Fauna of Australia, 1, pp.755-768.

The "Why do this?" part doesn't really explain why. Plenty of other creatures mark territory and attract mates, and they don't have square poops. Similarly the Wells quote seems unrelated.

@Parrotmaster: As nature continually proves, multiple solutions to the same problem exist. Plenty of creatures are land-based animals but that doesn't prove that birds shouldn't have evolved to have wings. Recognizability of feces may not have been the reason for its inception (random mutations tend to be the reason for the inception of a trait), but the subsequent benefit of recognizability of the uniquely shaped droppings may explain why the trait persisted.

@Parrotmaster take a look at Wells's paper for number of citations regarding the ethology and social-ecology of wombats

"Thus, the intestine stretches preferentially at the walls to facilitate cube formation." Sooo...the intestines are square?

probably means there are 4 muscles around the intestine that form a square.

@GraphTheory, no. The intestine supposedly just squeezes differentially due to varying elastic properties of the intestinal wall.

@gunfulker no. There aren't 4 muscles surrounding intestines. Rather, the intestines are composed of their own tubular smooth muscles which periodically squeeze (causing peristaltic movements of the contents)

On a more serious note than my comment, and as a supplement to theforestecologist's answer, it's worth pointing out that a cube with rounded corners and edges has larger surface area to volume ratio than a spherical dropping, making it more efficient for the reabsorbtion of moisture, which would be an evolutionary advantage in a place where water is in short supply (as it is in large parts of Australia).
Additionally, in respect of the claim made here that droppings are used for marking, it may be advantageous to have a dropping that doesn't roll, if it's important some subsequent visitor can identify the precise spot the droppings were dropped, especially if one inhabits sloped terrain (which a wombat does - mountainous areas of Australia) where a round dropping might roll and mark an ambiguous spot.

Why would feces reabsorbing moisture be an advantage? Do wombats eat their droppings?

@Paul I guess he meant colon absorbing moisture from feces to conserve water.

@Paul a standard function of the colon in all animals is to reabsorb nutrients and fluid from doo doo before it's expelled.


text:
Species Identification: Red velvety insect, India
What species is this?

Description:

Location: India
These insects came out just after overnight rain.
They were all over the place.
Their body looks like velvet.

Are these insects poisonous?

As you might have noticed from its appearance, this is a red velvet mite. This is an arachnid (related to spiders) and not an insect.
The red velvet mite apparently does not bite or sting (according to this website), and it is also used for medicinal purposes in India, according to this Wikipedia image, so it is unlikely to be dangerous.

If you haven't seen it already, the webcomic The Oatmeal has an amusing take on some of the arthropod's mating habits.

+1 for factually correct, complete answer (with Oatmeal link). A bit more detail on those 'medicinal purposes': "the inhabitants of Chhattisgarh use this mite (in combination with other herbal drugs) for the treatment of more than 10 important diseases including malaria, urinogenital disorders, paralysis, etc. Its use as sexual stimulant is most popular in the region".

I've noticed that whenever the locals believe fill-in-the-blank random plant/animal/insect/etc cures like 35 diseases and ailments and also bestows epic boners, chances are it does nothing.


text:
Why do myelinated axons conduct impulses faster?
How does the myelination help in better conduction? I would prefer answers that are not too technical please.

What research have you done before asking it here?

@Imi, be sure to check out my newly added answer to the linked question. I added it here first, but moved it after this question got close votes as a duplicate.

And where did this comment go 0.o?

Here


text:
Help me identify this caterpillar looking insect
Can someone please help me identify this caterpillar looking insect from the Caribbean?
Thanks.

Hi, if you specify the island, the habitat in which it was found and the dimensions of the caterpillars it helps the ID.

They look like the caterpillars of Alope sphinx (Erinnyis alope)

There is a webpage on a dedicated website here:
https://www.butterfliesandmoths.org/species/Erinnyis-alope
Among the pictures in the linked website you can find one with the green and brown morphs/stages of the caterpillars.


text:
Identification of a small to mid-sized, yellow moth species found in India at monsoon season

I am from India and it's monsoon here. What is the name of this insect?
Description:

Length: ~4cm
Width: ~2.5cm
Color: yellow, almost uniform across the wings. Slightly darker, dandelion yellow across the body.
Small black dot in the middle of each large wing.
White, speckled iridescence on wings.
Short antennae.
Longer than average hair for moths.

I am confused between Porthesia Atereta and Yellow Tussock Moth

This is likely a member of the Nygmiini moths. The Nygmiini are a tribe of tussock moths of the subfamily Lymantriinae (formerly called the Lymantriidae) of the Erebidae family

This is likely a member of the Nygmiini moths. The Nygmiini are a tribe of tussock moths of the subfamily Lymantriinae (formerly called the Lymantriidae) of the Erebidae family
A specimen that closely resembles yours can be seen here, and copied below:

I have not found a definitive species for you, but will keep looking. I'd advise you try to do the same given this information.


text:
What species is this grey insect with red antennae and mouthparts?
I’m very curious to know whether this is a type of ant or not, I only see 6 legs. Found in Tampa, Florida near Tarpon Springs.

Definitely not an ant.  Where was it?  I mean, it looks like it's in an old box with a strap...?  Is it rotten wood?  It looks like exterior lighting: was it outside buildings?

Also, how big is it?

See Horned Mohawk looking insect. What is it? for more info.

It was approximately 1 inch long, no bigger than an American 25 cent piece. Located on a farm in Tarpon Springs. Found crawling on the wash racks for the horses.

It's some type of Reduviidae, or assassin bug - possibly a juvenile wheel bug.  Here's a few pictures of Floridan assassin bugs I've found just browsing the net:

Tagged as unidentified Reduviidae from Tallahassee

Tagged as assassin bug

Tagged as a Wheel Bug

Tagged as a wheel bug nymph

Bottom line:
Not an ant, for sure: it's almost certainly in the family of Reduviidae, possibly the subspecies of Arilus cristatus.


text:
what is this bug ? i found it on bed 2 times
What is this 1mm long bug I found on my bed in Egypt?

Here is its back photo

It's a soft-bodied tick (family Argasidae). See Identification of a small flat bug for an example. Without providing us your location, nobody can give you a definitive ID. Please [edit] your post with more information.

Possible duplicate of Identification of a small flat bug


text:
Can you identify this red insect?
Location: Lansdowne, Uttarakhand, India
Date: 27 May 2017
Time: 5.33 pm
The insect was found walking upwards on a plastic table. It was about 3-4cm long, as far as I remember; its been a long time since I encountered it.
Spotted near a small shack in the Terai forests.

A note as to the animal's size might help (there isn't quite enough here to get that); other than that, I'm certain it's a true bug (Order Hemiptera, Suborder Heteroptera), and believe it to be a stink bug relative (Superfamily Pentatomoidea), but not knowing the Indian fauna I can't go deeper than that.

It looks like a nymph of eusthenes femoralis

This is a nymph of a shield bug in the Tessaratomidae family, commonly called tassarotimids (or sometimes "giant shield bugs" due to typically being 1.5 - 4.5 cm long).
According to Wikipedia:

They are mostly found in tropical Africa, Asia, and Oceania though a few species can be found in the Neotropics and Australia. There are about 240 species known

Of the subtaxa, only a few genera are even found in India:
Empysarus, Neosalica, and numerous in the subtribe Eusthenaria (e.g., Asiarcha, Aurungabada, Carpona, and Dalcantha). A key (Leston (1955)+)to this group of insects is available for purchase or institutional subscription on Wiley
Specific Taxa:
Similar to a comment under the OP's post suggests, this page appears to suggest that the nymph of a Eusthenarian called Eurostus validus (shown below) appears quite similar to the OP's specimen. However, I cannot find definitive record of E. validus being in India.

 Source: Vic wicked on Pinterest
the availability of useful information (keys, reputable websites, etc.) for this group of insects (especially for India and in English) are extremely limited, so I will just leave you here with the understanding that your insect is a tassarotimid nymph that is closely closely related to Eurostus validus, Eusthenes femoralis or some other member of the Eusthenaria.

 + Leston, D., 1955, April. A KEY TO THE GENERA OF ONCOMERINI STÅL (HETEROPTERA: PENTATOMIDAE, TESSARATOMINAE), WITH THE DESCRIPTION OF A NEW GENUS AND SPECIES FROM AUSTRALIA AND NEW SYNONYMY. In Proceedings of the Royal Entomological Society of London. Series B, Taxonomy (Vol. 24, No. 3‐4, pp. 62-68). Oxford, UK: Blackwell Publishing Ltd.


text:
Help me ID snake
Could someone please tell me if this is a cotton mouth?  Found 2 on my back porch, one got away.
Location: Fayetteville, AR (USA) [Note: there are several ponds nearby]

Hi, for a better identification, please read the recommendation in the species-identification tag wiki here

The head does not look triangular or big enough to be a cottonmouth. The few times I have encountered cottonmouths in my yard they have been very calm , do not scurry off quickly. ID depends on where you are : here in E Tex it could be a green water snake or a yellow-belly water snake. Is there water nearby ? If not , maybe a rat snake. I did kill a cotton mouth once by mistake ; It looked like a green water snake that eats fish in my ponds. The greens disappear fast so I hit it before I could look at it closely. Too late I saw it was a cotton mouth ( which do not like small ponds so rarely come here).

I live in Fayetteville, AR. Yes there are several ponds nearby, which is where we usually see cotton mouths.  Rarely do they venture into our back yard.

This is not a cottonmouth, it's Nerodia rhombifer, a diamondback water snake. It's nonvenomous and important for the ecosystem. Given that the water snakes compete with cottonmouths, it's important to not kill them to keep their populations high and not make room for cottonmouth populations to grow.

I had a diamond back water snake in my pond; He was much lighter in color , tan with brown "diamonds" .

Not certain why this post was downvoted given that it is the correct answer. Perhaps the downvoter doesn't believe in mutually-respectful dialogue. That's a shame.

Hi @ChrisMoore. Posts with citation notices generally attract downvotes (sometimes regardless of their correctness). I would advise providing a link or citation to a source that supports your answer. We're not looking for anecdotal comments, expert opinion, or short answers without explanations. We're looking for long answers that provide some explanation and context of why your answer is correct with citations/links to supporting evidence. [tag:species-identification] posts likewise benefit from providing images from reputable sources to further support your answer. Please revise. Thanks!


text:
Can anyone identify this tiny insect?
Very high magnification, size of a very small ant. Found in Menorca, spain

define "very small ant". One millimeter in length?

I would say 2mm/3mm but that's a guesstimate now as these have gone.

These are Barklice (order "Psocoptera"); the out-of-focus photo will probably forbid going deeper.

That's a barklouse, order Psocoptera. https://en.wikipedia.org/wiki/Psocoptera
It's very hard to identify those to species in a picture.


text:
How far can parrots fly without needing to land?
This is for a story I'm writing.  I can't find any information on how far various parrot species can travel without needing to land-- the closest I could find is this page saying that a macaw flies up to 15 miles looking for food.  Intuitively I would think that larger birds, like macaws and African greys, would be able to fly farther than smaller ones due to having stronger wings, but the nonstop-flight record-holder is about the size of a robin so I guess that's not necessarily true.
Can anyone tell me how far various parrots can fly in a stretch, or at least the farthest that any parrot species can fly?

related https://biology.stackexchange.com/q/23530/3340

@David. This site is open to anybody that wishes to use it. The OP clearly is asking a biological question which is on-topic here. It doesn't matter what their end-use of this information is. Please review our on-topic guidelines and our Code of Conduct. Most importantly, be nice to new users!

@theforestecologist — OK, then it’s off-topic because he should have done his own research. I know nothing about parrots (other than you’re not supposed to shoot them in Australia) but was able to find an answer in a few minutes googling (at parrot.org). The site is supposed to be for serious students of biology and I think this sort of question is too like a Guinness Book of Records question.

@David Could you provide a link?  I haven't been able to find an answer to this, and parrot.org doesn't seem to be at all related to my question.

The page I found was https://www.parrots.org/ask-an-expert/comparison-of-flight-mileage-for-various-wild-parrot-species. It is a bit iffy in that some of the figures are miles per day (presumably landing in between) but others are non-stop between islands. Probably not as much detail as you would like, but a start. I searched for "range of flight of parrots". Another problem is that there is a drone with the name "parrot" so best to use plural.

@David this is actually a legitimate question: "What is the max/average flight duration of ___ species of bird?". Unfortunately, proper references are available only for some few selected species of migratory birds.

@WYSIWYG — See my response to theforestecologist. Ironic that I'm the only person that has provided anything.

Birds of flight were the original inspiration for the design of a machine that could fly and carry a person aloft, hence it's not surprising that the aerodynamics of avian flight and aircraft have much in common. Specifically, they both consume mass as the source of energy to maintain flight; jet fuel or gasoline in the case of airplanes, and stored body fat in birds, and they both have wings that provide aerodynamic lift as the air moves over them during flight. In addition, both share another characteristic of flight, the ability to glide, to continue flight without providing any of their own energy to maintain that flight. This energy is provided by the atmosphere itself in the form of rising air currents caused by a difference in temperature of a local 'pocket' of air; a pocket of air that is warmer than the surrounding air will rise because it has lower density, the Archimedes Principle in action. A similar process occurs when a parcel of moist air is surrounded by dry air at the same temperature as the moist air hence less dense than dry air. The third source of rising air is due to the local topography; the air on the windward side of a ridge or mountain is forced upward and is frequently used by birds as a source of lift.
Any discussion of gliding flight will unavoidably involve some aspects of atmospheric physics (a.k.a., weather), it's no different here. As stated above, a parcel of moist air surrounded by dry(er) air at the same temperature will rise. As long as that temperature is above the saturation temperature (the dew point) for that parcel of air, the water will remain in vapor form. We all know that as we go higher in the atmosphere the temperature drops; it's cooler at the top of a mountain than at its base. Therefore, as our parcel of moist air rises its temperature will drop, and eventually that temperature is the same as the dew point in that parcel leading to the condensation of that moisture, i.e., a cloud forms. As a surface of constant temperature in the atmosphere is nearly a level surface, we see clouds in the sky whose bases are all at the same level, the level where this condensation begins. Now, for a little of thermodynamics; when we boil water by adding heat (that is energy) to it, we are turning liquid water into a vapor (steam). Here's the thing, when we cool that steam down to the dew point it will condense back into liquid water, and in doing so, we get the heat (that was put in to make it boil) back again! That recovered heat shows up as an increase in temperature of the air that just gave up the water vapor. This increase in temperature causes that air to continue to rise, now due to a temperature difference with the surrounding air rather than a water vapor pressure difference; the cloud continues to grow upwards. This is the source of the cumulonimbus clouds we see in the sky that may eventually form thunderstorms. This discussion hi-lights a key fact about weather that relates directly to our discussion about gliding flight; if there are no updrafts, there are no clouds. That's correct, for a cloud to form, there must be updrafts containing moist air. No clouds indicates no updrafts. If there are no updrafts, there is no gliding flight. However, we note that really dry air is very hard to find; there still might be thermals around, but not likely, and those not very strong. The take away from this discussion is this: if we want to include increases in maximum range resulting from gliding flight, we need to be able to predict the weather (which hasn't happened yet, and I say this as one who has spent years as an undergraduate and graduate student active in atmospheric research.). Hence, long distance gliding flight will not be addressed any further here.
We begin our analysis of powered flight by considering a specific airplane, say a Boeing 787 passenger jet. To find its maximum range, the aircraft would be completely fueled up, take off and fly a level, constant speed flight path, as any accelerations (by changing altitude or going faster) would waist fuel. When the fuel tank goes dry, you have reached the maximum range of powered flight (assuming no head or tail winds of course).
From an analytic point of view, the fuel carried by the 787 is the source of energy, $E_s$, that powers its engines. These engines produce the thrust force, $\mathbf{T} = T\mathbf{\hat{T}}$ directed horizontally, parallel to the 787's longitudinal axis and to the flight path, that counteracts the effect of the atmospheric drag force, $\mathbf{D} = D\mathbf{\hat{D}}$ that opposes the 787's motion along its flight path. Under steady flight conditions (constant speed and altitude), the net horizontal forces on the 787 is zero so that $\mathbf{T} + \mathbf{D} = \mathbf{0}$, or $\mathbf{D}=-\mathbf{T}$. Taking the magnitude of both sides of this expression we find that $D=T$ so that $\mathbf{\hat{D}}=-\mathbf{\hat{T}}$. We find that the thrust generated by the engines has the same magnitude as, but directed opposite to the atmospheric drag.
Under the same flight conditions, we find a similar relationship for the vertical components of force acting on the 787, its weight, $\mathbf{F}_w = F_w\mathbf{\hat{F}}_w$ is balanced by the lift $\mathbf{L} = L\mathbf{\hat{L}}$ generated by the wings so that $F_w = m_p g = L$ and $\mathbf{\hat{L}}=-\mathbf{\hat{F}}_w$ where $m_p$ is the instantaneous mass (= takeoff mass of the plane, $m_{p_0}$, less the mass of fuel expended so far generating thrust) of the 787 and $g=9.8\, \text{m/s}^2$ is the standard gravitational acceleration on the surface of the Earth. We note here, that under these flight conditions, both $\mathbf{L}$ and $\mathbf{F}_w$ are perpendicular to $\mathbf{T}$ and $\mathbf{D}$.
If the thrust is removed so that $\mathbf{T}=\mathbf{0}$, then the drag force will no longer be opposed and will slow the plane down, reducing the speed of air flowing over the wing, which in turn will cause the wing to generate less lift, thus initiating the plane's descent (its weight is greater than the lift produced by the wings). If the plane is then 'nosed down' by an angle $\alpha$ from the horizontal, the projection of the plane's weight vector, $\mathbf{F}_w$ onto the plane's longitudinal axis will no longer be zero, but will instead be $\mathbf{F}_w\sin\alpha$ directed forward opposing the drag force. If $\alpha$ is chosen so that the sum of this projection and the drag vector is zero, then the plane will descend at a constant rate and the magnitude of the drag is given by $D = F_w\sin\alpha$. The projection of the weight vector onto the axis perpendicular to the plane's longitudinal axis, $\mathbf{F}_w\cos\alpha$, is balanced by the equal magnitude but oppositely directed lift vector, whose magnitude now becomes $L = F_w\cos\alpha$. If we form the ratio $D/L$ we find
\begin{equation}
\frac{D}{L} = \frac{F_w\sin\alpha}{F_w\cos\alpha} = \tan{\alpha} \tag{1}\label{1}
\end{equation}
The inverse of this ratio, $L_D = L/D = (\tan\alpha)^{-1}$, is known in aerodynamics as the lift to drag ratio while the angle $\alpha$ is called the glide slope angle. These two  parameters are important in the overall characterization of the aerodynamics of an air-frame. Once this ratio is known, it can be used to estimate the drag in level flight. But in level flight, the lift is equal in magnitude to the plane's weight, $L=F_w=m_p g$. Substituting this expression into Eq.~$\eqref{1}$ and solving for the drag
\begin{equation}
D = L\tan\alpha = F_w\tan\alpha = m_p g\tan\alpha  \tag{2}\label{2}
\end{equation}
We have reached the point in our analyses that we need to address the mass/energy budget for the plane's flight. It will be useful to separate the mass of the plane into its empty (no fuel) mass, $m_{p_e}$, and the mass of available fuel, $m_f$, with the initial, takeoff mass of fuel given by $m_{f_0}$. With these quantities defined, the initial takeoff mass of the plane is given by $m_{p_0} = m_{p_e} + m_{f_0}$ while the instantaneous mass is given by $m_p = m_{p_e} + m_f$. During flight, the mass of the fuel available, $m_f$, varies such that $m_{f_0} \ge m_f \ge 0$ while the mass of the plane, $m_p$, varies as $m_{p_0} \ge m_p \ge m_{p_e}$.
There are two additional constants required to determine the net effective energy available to do work against the drag force when consuming the (differential) quantity $\delta m_f$ of fuel while flying the (differential) distance $\delta \mathbf{r}$. The first of these, $\kappa$, determines the total (differential) energy, $\delta E$, available from the combustion of the quantity $\delta m_f$ of fuel
\begin{equation}
\delta E = \kappa \delta m_f   \tag{3}\label{3}
\end{equation}
For an American airplane such as the 787, $\kappa$ will have units something like BTU per pound of fuel expended.
The second, $\eta$, specifies the efficiency of converting the available energy into actual work, $\delta W$, generating thrust that counteracts the drag
\begin{equation}
\delta W = \eta \delta E = \eta \kappa \delta m_f = - \mathbf{T}\cdot\delta\mathbf{r} = - m_p g\tan\alpha \delta r \tag{4}\label{4}
\end{equation}
where $\delta\mathbf{r} = \delta r \mathbf{\hat{T}}$ is a differential displacement vector along the flight path during constant velocity, horizontal motion and the minus sign accounts for the fact that the plane's energy stores are consumed as that energy is used to counteract drag (a fundamentally dissipative process).
Letting the $\delta$'s become derivatives, dividing through by $m_p$ and using $m_p = m_{p_e} + m_f$ and replacing the integrated variables by primed quantities, , Eq.~$\eqref{4}$ can be rewritten in the integral form
\begin{equation}
\eta \kappa \int_{m_{f_0}}^{m_f} \frac{dm'}{m_{p_0} + m'}
= - g\tan\alpha \int_0^r dr'   \tag{5}\label{5}
\end{equation}
with the limits of integration evaluated at takeoff and the current downrange position a distance $r$ from takeoff.
Performing the integrations indicated in Eq.~$\eqref{5}$ and simplifying, we have the result
\begin{equation}
m_p = m_{p_0} e^{-\frac{g\tan\alpha}{\kappa\eta}r}   \tag{6}\label{6}
\end{equation}
We find that the mass of the plane, $m_p$, is an exponentially decreasing function of the distance flown, $r$. Letting $r=r_m$ be the maximum range of plane where all fuel has been expended (when $m_f=0$ so that $m_p = m_{p_e}$), Eq.~$\eqref{6}$ becomes
\begin{equation}
m_{p_e} = m_{p_0} e^{-\frac{g\tan\alpha}{\kappa\eta}r_m}   \tag{7}\label{7}
\end{equation}
We note the similarity of this expression to that of the Tsiolkovsky rocket equation.
Eq.~$\eqref{7}$ can be solved for the maximum range $r_m$
\begin{equation}
r_m = \frac{\kappa\eta}{g\tan\alpha}\ln\left(\frac{m_{p_0}}{m_{p_e}}\right)
   \tag{8}\label{8}
\end{equation}
an amazingly simple result, all things considered! This result remains valid for any aerodynamic system that obtains its lift via forward motion through the air provided by a propulsion system that consumes mass to produce thrust. It could be applied to a Cessna 172, or even a nitro powered radio controlled (RC) model of a 172. It could not be applied to an electrically (battery) powered model of the 172 because there is no mass loss from a battery, or to any type of glider (no thrust or mass loss). And it can, however, be applied to any bird of flight, including our parrot!
For the parrot, the energy source is the fat stored in its body. This mass is consumed through metabolic processes that convert it into $\text{CO}_2$ and water vapor that is expelled during respiration, and as sweat and urine as the parrot flies (the parrot's "exhaust" as it were!). The energy content of body fat ($\kappa$ as defined in Eq.~$\eqref{3}$) is 9 (food) Calories per gram. One food Calorie is equal to one kilocalorie which is in turn equal to 4184 Joules in SI units, see the Wikipedia article Food energy.
The efficiency of converting stored energy in the human body into mechanical work has been estimated to be $18\%$ -- $26\%$ (see Wikipedia page Muscle). One would expect similar numbers for other warm blooded vertebrates, so that, to one significant figure, we take $\eta = 20\% = 0.2$ (a dimensionless quantity).
There seems to be a very broad range for the percent of body mass that is fat. Some migratory birds have up to $70\%$ (see Obese super athletes: fat-fueled migration in birds and bats, however the parrot is not generally considered a migratory bird. The web page Comparison of flight mileage for various wild parrot species states a migration distance of 320 km for Thick-billed Parrots for example. Hence the $70\%$ number is likely far too large. At the other extreme, ground beef is considered lean if it contains $10\%$ fat, but more generally it is closer to $20\%$. We will select a value somewhat below the median of these extremes, say $35\%$.
A typical mass for a parrot is another difficult number to ascertain, as there is a very large difference in body mass for the various members of the parrot family. For example, the web page Average Bird Weights of Common Parrot Species gives data for 52 parrot species with links to four other species, each with several entries. These vary from 10 grams for the Zebra finch to 1530 grams for the Green-winged Macaw covering a mass range of over two orders of magnitude! Upshot: there is no such thing as a "typical" parrot! We will choose the Thick-billed Parrot as we have some long distance data to compare our result to. The Wikipedia page Thick-billed parrot gives its mass range as 315-370 grams, we shall use 370 grams so that $m_{p_0} = 0.37 \, \text{kg}$, $35\%$ of which is to be considered fuel so that $m_{f_0} = 0.16 \, \text{kg}$ leaving the parrot's 'empty mass' at $m_{p_e} = 0.24 \, \text{kg}$.
We have one remaining parameter to estimate, that being the glide slope angle, $\alpha$, used to find the lift to drag ratio above. Consider the order of magnitude estimates of $\alpha = 10^0 = 1\, \text{radian} \approx 60^o$, $\alpha = 10^{-1} = 0.1\, \text{radian} \approx 6^o$ or $\alpha = 10^{-2} = 0.01\, \text{radian} \approx 0.6^o$. Clearly $60^o$ is far too steep and $0.6^o$ is much too shallow, leaving $6^o$ as the only acceptable order of magnitude choice, hence we set $\alpha=10^{-1}$ radian, a number valid for most birds of flight.
Repeating Eq.~$\eqref{8}$ above,
$$
r_m = \frac{\kappa\eta}{g\tan\alpha}\ln\left(\frac{m_{p_0}}{m_{p_e}}\right)
$$
and substituting the parrot's values from above (including unit conversion factors)
$$
r_m= \frac{\left[\left(\frac{4184\,\text{J}}{\text{gm}}\right)
\left(\frac{1000\,\text{gm}}{\text{kg}}\right)
\left(\frac{\text{kg m}^2}{\text{J s}^2}\right)
\right] \left(0.2\right)}
{\left(\frac{9.8\,\text{m}}{\text{s}^2}\right)
\left(\tan\left(0.1\right)\right)}
\ln\left(\frac{0.37\,\text{kg}}{0.24\,\text{kg}}\right)
\approx 370 \text{ km }
$$
we find the answer to the question, "How Far Can a Parrot Fly [under power] in a Single Day?" to be
$$
\boxed{r_m\approx 370\, \text{km}}
$$
a number which is in close agreement with the (limited) data available which gave an actual (vs maximum) daily migration range of 320 km.
It's interesting to note that this maximum range for powered flight can be viewed as the minimum range when gliding flight is included. Under ideal weather conditions, the actual maximum range could be extended considerably if the parrot were to capitalize on any available thermals it encountered during its flight.


text:
Bug Identification: Tiny Bugs
I have seen these on my hands recently and I am wondering what they are. Urban Setting. South Central Pennsylvania.

Please comment about whether you have any animals (especially birds) living in or around your home. Thanks.

Related: Tiny white very hard cell bug! Please help to identify!

@Erik K Looks like maybe you have two accounts..You can merge them together if you'd like. See here for instructions. Let me know if you have any issues

This appears to be a bird mite (or possibly rat mite) in the genus Ornithonyssus of the parasitic family Macronyssidae.

 Credit: user Aewills on bugguide.com
Identification:
From Central Exterminating Co.:

The mites are distinguished from most other common, structural species by the very long legs and very long mouthparts. These long, pointed chelicerae and palps stick well out in front of the head region. The 8 legs are very long and well separated, allowing for good mobility by these mites. The body is oval, with the thorax and abdomen combined to a single segment without separation. The color is light grayish in unfed mites to reddish orange in mites recently having had a blood meal. The fowl mites often seem to have a patchy, mottled appearance of dark areas.

Distinguishing between species is difficult.

As for knowing the specific species, citybugs.tamu.edu suggests:

Distinguishing between different species of Ornithonyssus mites to determine whether birds or rodents are the likely source is difficult and requires special expertise.

Blaine Mathison mentions the following features useful for identifying these mites to lower taxonomic levels under magnification [source: bugguide.com]:

chelicerae shape
dorsal plate breadth and degree of dorsal coverage
spiracle present between legs
genitoventral plate width
sternal plate shape and presence of setae

(see the linked post for pictures and more detail).
You can see videos of these mites crawling on people here and here.
Regarding their affects on humans:
From Penn State Extension:

Bird mites have piercing mouthparts that enable them to take blood meals from their
bird hosts. Although the mites will inadvertently bite people, they cannot reproduce without their bird hosts...

As the mites search for an alternative host, they will crawl onto the skin and conduct an exploratory bite to test the appropriateness of the host. The mite will move on, possibly trying the host again, but will not feed. These bites are felt as a “prick” and a resultant rash and itching, sometimes intense, will occur. Some individuals are apparently capable of sensing the crawling of the mites on the skin. The irritation produced by the bite is enhanced by the injection of the mite’s saliva that can cause a localized histamine
response.

Management:
Remove birds (and especially nests) from on or near the building. Check for any holes in your building that could be large enough to allow birds inside. Again, these mites need birds to reproduce, so if you eliminate the birds eventually these will disappear. See PSU Extension and Central Extirminating Co. for more suggestions.

Congratulations, you have baby cockroaches!  I have lived with many.  Their shape and coloring changes with age.  Your organism walks too fast and is too big to be a parasitic mite.  So this is good news.

You are more likely to get a positive response to your answer if you explain why your identification is correct. Specifically, please [edit] your answer to add discussion of key features that led you to this conclusion and supporting references or at least validated images. Without this your answer is indistinguishable from opinion. In particular you are disagreeing with someone with a well-established reputation for excellent answers — they could be wrong, but you really need to demonstrate that rather than making unsupported assertions.


text:
What is the duration between: the moment we stop breathing and to body's and involuntary mucle movement?
I studied that if someone stops breathing by pressing their nostrils with fingers and start to starve without oxygen, the body will automatically cause the hands to leave the nostrils in a certain time so that we can breathe. (a kind of reflex, I guess)
What is this certain time?

Could you include a source for where you studied that? Thanks.

I found it in many sources, one is https://www.healthline.com/health/holding-your-breath#what-happens

Have u seen the above comment @user438383

The link you gave doesn't say anything at all about the body "automatically" causing the hands to leave the nostrils. That will happen when you black out, as your muscles become flaccid and gravity causes your hand to move away from your face, but there's no "automatic" movement...

Your respiratory system has quite a number of neural and non-neural (e.g., physical, emotional, and chemical factors) controls in addition to the ability to be voluntary controlled.

A strong influence on much of our respiratory physiology is a response to changes in carbon dioxide in the blood (well, more specifically, it's blood pH that is regulated).  Oxygen homeostasis is also controlled.

As a result, the duration you're asking about almost certainly is dependent on total lung capacity, actual volume of air inhaled, diffusion capacities, activity levels, etc. as each of these would determine levels of oxygen and CO2 in the blood and available to tissues (such as the brain).

In other words, since gas homeostasis plays such a prominent role in respiratory control, the duration of any "reflex" response would vary between person to person (based on their anatomy) and even for an individual person based on circumstances.

Also, I'm not personally familiar with any such reflex that you mention.*

In fact, some children intentionally hold their breath until they pass out! This passing out is actually a useful adaptation because it allows the body to return to using involuntary breathing controls to prevent the child from depriving themselves of oxygen long enough to induce death. Seattle Children's Hospital suggests normal breathing returns in under 2 minutes.

Also see the fainting game that got popular among teens earlier this century that involved intentionally causing self syncope. [WARNING: DON'T BE THIS STUPID]

* If you can update your question with a source or any additional information about the "reflex" you mention, I or someone else might be able to address the reflex or your source of info more specifically.


text:
What’s the name of this insect that looks like a leaf? I found it in Taiwan
Found it in a tea plantation. It can jump.

It appears to be a Tituria planata nymph.

The adults look like this:

At first I thought it was a treehopper, but it turns out that it was a leafhopper (they are similar but different).
Tituria planata is one of the most common leafhopper species in Taiwan.
https://www.inaturalist.org/observations?place_id=7887&taxon_id=49025&view=species
Image source 1
Image source 2


text:
Which beetle is this?
I'm curious to find out what kind of beetle this is. Google lens search suggested a type of longhorn beetle, but I am not convinced.
The photo is taken in Karnataka, in India
Thanks!!

Welcome to Biology.SE! Please [edit] your post to include habitat information and an estimate of the size of the organism. This information may be essential for an accurate identification. ——— If possible clear, closeup photos of the creature from multiple angles would also be helpful. ——— You may also benefit from taking the [tour] and then going through the help pages starting with [Ask] questions effectively on this site. Thanks!

This is a beetle from the family of the "longhorned beetles", since you found this beetle in India, I think this is Acanthophorus serraticornis
See the images for comparision (from here and here):

There is not much information online, but some can be found here and especially  here in this scientific article. The larvae of this beetles are considered a pest, as the bore into wood.


text:
Same primers and different melting peaks for two samples (~1°C appart)
In the figure, you can see that melting peaks differ by ~1°C at each sample.
Should I be worried?

I would have said that 1⁰C is not a significant difference but the technical replicates are so perfectly matching!! Are these samples from same source (tissue/cells etc)?

they are the same tissue (oviduct) from two different animals


text:
Human Bones classification and anatomy quiz
I'm a junior Biology Student and I came across this Human Anatomy Question:
In respect to the bone characteristics, mark the correct answer:
A) Even bones: Palatine, Inferior jaw, Parietal.
B) Examples of Long Bones: Sternum and Radius-clavicle.
C) Some Mixed Bones are (I couldn't find a better translation for "ossos mistos" in portuguese): vertebrae, ribs, hip bones.
D)Plane Bones protect organs and form cavities, for instance we have: Ribs and Sternum.
E)Odd and Plane Bones: Occipital, Frontal and Sternum.
I am almost sure that options A through C are incorrect. I'm between options D and E, but in option E I am really sure only that the Sternum Bone is correct. I couldn't find a reliable source that said explicitly that the Occipital and Frontal Bone are Plane and Odd.
And I think option D has a flaw mainly because the Sternum Bone does not form any cavities.

As you not in your question, I think there are some difficulties in translation. I suspect that "plane" should be translated as "flat", that "mixed" is likely "irregular", and "odd" and "even" are "paired" and "unpaired". Does that sound right?

If you are voting down, please leave a comment.

Why do you think the answer C is incorrect?  %)

@kmm - here a new downvote. I am downvoting because this is a schoolbook example of a  set of dry, contentless textbook-answerable questions not quite interesting for this community at large. I can't vote for closure as it is on topic. So, a downvote it is.

@AliceD I disagree. Here's a question with a valid attempt at answer, seeking clarification. Seems like a reasonable homework question. Maybe not the more interesting, but valid and worthy of answering.

@kmm - it's a downvote, nothing more. I voted to leave open. I support this question, I just don't think it rocks because it is so textbooky.

It would be good if you posted the original text in Portuguese so someone fluent in both languages can translate it better, as is the translation issues are preventing the question from being answered.

@Jessica Veloso (if you ever return to SE), did you ever get the answer to see if our attempts at translating were correct?? :p

@KMM's comment above appears to be on the right rack.
"plane" = "flat"
"mixed" = "irregular"
"even" & "odd" = "paired" & "unpaired"

That being said:

A = FALSE because jaw bones are not paired
B = FALSE because sternum is not a long bone (it's a flat bone)
C = FALSE because ribs are not irregular bones (they're flat bones)
D = TRUE because both are flat bones and protect organs
E = FALSE but ONLY under the assumption of the persistence of a metopic suture (frontal suture) causing the frontal bone to be split (and therefore "paired").

If I had 90 seconds to answer this question I'd mark answer "C".
Vertebrae & Ribs & Hip bones all are mixed bones.


text:
Is this a venomous (poisonous) spider?
Today I found a spider in my home that I have never seen before.
I live in Karachi, Pakistan.
I want to know which spider is this and if it is venomous and danger for me or my family ?? Is this spider commonly found in homes. I have seen many home spiders but they were never like that.
The spider is around 2cm long (front legs to back legs span as shown in 1st image)

This looks like either a young or rather hungry Theridiid spider.  I am not particularly experienced with Eurasian spiders, but as far as I know, the only Widows you're likely to come across in Karachi are either the Redback (Latrodectus hasselti) or the relatively non-problematic Brown Widow (Latrodectus geometricus).  This does not appear to be either of these - the front pair of legs is nice and long, but the abdomen is too plain and the bands at the leg joints are not particularly dark brown and contrasting.
Young female Brown Widow from Bug Guide:

Male Widows, both Black and Brown, tend to have small, rather stripy abdomens, and as adults, will have enlarged ball-like structures at the end of the face-mounted pedipalps.
Male Black Widow from Bug Guide:

That just leaves one of the medically unimportant Theridiids as the most likely candidate, and that's where I unfortunately cannot help any further.  Still, the rule of thumb is that unless you identify it as a problem biter, it's not worth worrying about.  The trick is to look at its underside.  If it shows a red hourglass, it's a problem - if not, no worries.
Judging by the photos, I'd go with "no worries", unless you can come up with a clear image of something troublesome.
I include references to support my claims regarding the distribution of Widows in Pakistan:
https://pdfs.semanticscholar.org/f7c7/3ec7c79da6b3b685e4f05649069c4717803e.pdf
http://eprints.iisc.ac.in/15097/1/First_report_of_the_brown_widow_spider%2C.pdf


text:
Do flies avoid infrared light?
If flies avoid IR light, many places can be kept free from flies using IR light. We see insect repellers in many restaurants, but they don't seem to work well. Can IR be a safe & effective alternative?

Hi and welcome to Bio@SE. What have you done to answer your question? you should edit your question to add this information, it will help you get more specific answers

What kind of "flies"?

I doubt very much that sunlight, what they like to bask in, is an issue for them. UV and Blue light you mean? is use in fly traps?!?! flies are made to spend all day in light, and IR by it's nature is the most beneficial light as it's in between a mug warmth and an LED. anything warm is likely to emit IR.


text:
What is this agglomeration of pink cells I found attached to a stone?
Photo taken in a garden in Singapore. The organism is attached to a stone, close to water. Many of these were there.
Size approx 3cm.
The shell of this eggs is very soft. When touched, a pink colored liquid drops out.

They are Apple snail's eggs; check the picture:
Check this.

This could very well be the eggs from an apple snail (family Ampullariidae).
According to Wikipedia

Several apple snail genera (Pomacea, Pila and Asolene/Pomella) deposit eggs above the waterline in calcareous clutches. This remarkable strategy of aquatic snails protects the eggs against predation by fish and other aquatic inhabitants.

If these are in fact the eggs from an apple snail, then the parent is likely in the genus Pila since this is the only major genus found in Asia [source].
You can see a timelapse video of a snail laying eggs here and a short gif below:

 Source: gfycat
See applesnail.net for more info.


text:
Carbon Dioxide, sea water, diatoms, and oxygen
I recently viewed a documentary called “Flying River Observed in Tallest Structure in South America, National Geographic”  (https://www.youtube.com/watch?v=HjpPsZTwsaM).  In this film, as an aside, it was mentioned that a major source (the major source?) for the oxygen required for life on earth are the diatoms in sea water.
It was mentioned that diatoms have shells.
In a separate article (whose source I do not remember) it was mentioned that the sea, because it is being  exposed to higher and higher atmospheric  carbon dioxide levels, was becoming more and more acidic. This high acidity was making it difficult for sealife to form shells.
Will this decrease the number of diatoms in sea water?
Will this affect the amount of oxygen available to life on earth?

Lower pH (from CO2 reacting with ocean water to form carbonic acid) makes formation of bicarbonate shells more difficult. this would reduce the fitness of any bicarbonate-shell forming organisms. However, diatoms, to the best of my knowledge, usually have shells made of silica, so I am not sure to what degree lower pH water will have on the formation of their shells and their overall fitness. However, communities and competitive interactions would certainly change as other organisms' fitnesses are impacted, which very well could impact diatoms indirectly.


text:
Bug identifying

Can anyone help me identify this insect found in my office today?

If you could let us see the top-side of the bug, it would help us identify it.

It can help identification, if you add the approximate size and the geographical local of that bug.

That is a stink bug, order Hemiptera, family Pentatomidae. My guess is that it is a brown marmorated stink bug Halyomorpha halys, not because I can identify it as such, but rather, because this species frequently invades homes. https://en.wikipedia.org/wiki/Brown_marmorated_stink_bug