in snake (such as rattlesnake) and lizard venoms. Cytotoxins, which kill individual cells and are found in the apitoxin of honey bees and the venom of black widow spiders. Taxonomic range Venom is widely distributed taxonomically, being found in both invertebrates and vertebrates, in aquatic and terrestrial animals, and among both predators and prey. The major groups of venomous animals are described below. Arthropods Venomous arthropods include spiders, which use fangs on their chelicerae to inject venom; and centipedes, which use forcipules, modified legs, to deliver venom; while scorpions and stinging insects inject venom with a sting. In bees and wasps, the sting is a modified egg-laying device – the ovipositor. In Polistes fuscatus, the female continuously releases a venom that contains a sex pheromone that induces copulatory behavior in males. In wasps such as Polistes exclamans, venom is used as an alarm pheromone, coordinating a response with from the nest and attracting nearby wasps to attack the predator. In some species, such as Parischnogaster striatula, venom is applied all over the body as an antimicrobial protection. Many caterpillars have defensive venom glands associated with specialized bristles on the body called urticating hairs. These are usually merely irritating, but those of the Lonomia moth can be fatal to humans. Bees synthesize and employ an acidic venom (apitoxin) to defend their hives and food stores, whereas wasps use a chemically different venom to paralyse prey, so their prey remains alive to provision the food chambers of their young. The use of venom is much more widespread than just these examples; many other insects, such as true bugs and many ants, also produce venom. The ant species Polyrhachis dives uses venom topically for the sterilisation of pathogens. Other invertebrates There are venomous invertebrates in several phyla, including jellyfish such as the dangerous box jellyfish, the Portuguese man-of-war (a siphonophore) and sea anemones among the Cnidaria, sea urchins among the Echinodermata, and cone snails and cephalopods, including octopuses, among the Molluscs. Vertebrates Fish Venom is found in some 200 cartilaginous fishes, including stingrays, sharks, and chimaeras; the catfishes (about 1000 venomous species); and 11 clades of spiny-rayed fishes (Acanthomorpha), containing the scorpionfishes (over 300 species), stonefishes (over 80 species), gurnard perches, blennies, rabbitfishes, surgeonfishes, some velvetfishes, some toadfishes, coral crouchers, red velvetfishes, scats, rockfishes, deepwater scorpionfishes, waspfishes, weevers, and stargazers. Amphibians Some salamanders can extrude sharp venom-tipped ribs. Two frog species in Brazil