[19] In males/females, the ventral scales number 130-145/128-144 and the subcaudals 38-54/36-50. [3] As an adult, it is large and capable of delivering a painful and potentially fatal bite. Total length, per one study of adults, was 65 to 90 cm (26 to 35 in). Eventually, all of her offspring retreated into the chamber, but the female remained at the entrance, ready to strike. At this point, they moved to higher ground and could be found in rotting pine stumps by tearing away the bark. For example, watersnakes usually flee quickly into the water, while A. piscivorus often stands its ground with its threat display. [1] Species are listed as such due to their wide distribution, presumed large population, or because they are unlikely to be declining fast enough to qualify for listing in a more threatened category. An important factor in sexual selection, it allows for the establishment and recognition of dominance as males compete for access to sexually active females. Its range also includes the Ohio River Valley as far north as southern Indiana, and it inhabits many barrier islands off the coasts of the states where it is found. Florida Cottonmouth Eastern populations have a broad, dark, postocular stripe, bordered with pale pigment above and below, that is faint or absent in western populations. They often emerge at sunset to warm themselves on warm ground (i.e., sidewalks, roads) and then become very active throughout the night, when they are usually found swimming or crawling. The dorsal banding pattern fades with age, so older individuals are an almost uniform olive-brown, grayish-brown, or black. The name cottonmouth comes from the fact that its mouth looks like cotton when it is open. [33], Agkistrodon piscivorus venom is more toxic than that of A. contortrix, and is rich with powerful cytotoxic venom that destroys tissue. Wright and Wright (1957) report having encountered these snakes on countless occasions, often almost stepping on them, but never being bitten. "Natural history notes: Wharton CH (1960). These crossbands are visibly lighter in the center, almost matching the ground color, often contain irregular dark markings, and extend well down onto the ventral scales. However, it is not fully marine, unlike true sea snakes. [4] Individuals may bite when feeling threatened or being handled in any way. [34], Bites from the cottonmouth are relatively frequent in the lower Mississippi River Valley and along the coast of the Gulf of Mexico, although fatalities are rare. [16] This musk may be ejected in thin jets if the snake is sufficiently agitated or restrained. He suggested this might have something to do with hibernating habits. ), brown snakes (Storeria dekayi), garter snakes and ribbon snakes (Thamnophis spp. ), other cottonmouths (A. piscivorus), rattlesnakes (Crotalus spp. In A. piscivorus, the loop is raised laterally, with the belly facing towards the attacker. When one of the young was moved a short distance from the chamber, she seemed to be agitated and faced the intruder. A two-headed snake was found in Northern Virginia earlier this year. [28], When sufficiently stressed or threatened, this species engages in a characteristic threat display that includes vibrating its tail and throwing its head back with its mouth open to display the startlingly white interior,[24] often making a loud hiss while the neck and front part of the body are pulled into an S-shaped position. "Venom Poisoning in North American Reptiles". [16], Though the majority of specimens are almost or even totally black, (with the exception of the head and facial markings), the color pattern may consist of a brown, gray, tan, yellowish-olive, or blackish ground color, which is overlaid with a series of 10–17 dark brown to almost black crossbands. [16], Parthenogenesis is a natural form of reproduction in which growth and development of embryos occur without fertilization. ), true frogs (Rana spp. [19] In various locations, the species is well-adapted to less moist environments, such as palmetto thickets, pine-palmetto forest, pine woods in East Texas, pine flatwoods in Florida, eastern deciduous dune forest, dune and beach areas, riparian forest, and prairies. Subadult specimens may exhibit the same kind of dark, parietal spots characteristic of A. contortrix, but sometimes these are still visible in adults. [11], Brown (1973) gave an average venom yield (dried) of 125 mg, with a range of 80–237 mg, along with LD50 values of 4.0, 2.2, 2.7, 3.5, 2.0 mg/kg IV, 4.8, 5.1, 4.0, 5.5, 3.8, 6.8 mg/kg IP and 25.8 mg/kg SC for toxicity. [33] This likely involves recombination at the tips of the chromosomes, which leads to genome wide homozygosity. McDaniels took a photo and just happened to catch the snake with its mouth open, as it … ), common snapping turtles (Chelydra serpentina), mud turtles (Kinosternon spp. ), sirens (Siren spp. [16] Contrary to popular belief, they are capable of biting while under water. 10.2305/IUCN.UK.2007.RLTS.T64298A12756313.en, "Water Moccasin, Cottonmouth: Different Names, Same Venomous Snake", "The cottonmouth moccasin on Sea Horse Key, Florida", https://www.youtube.com/watch?v=wKc3EcAQQSQ, "312 IAC 9-5-4: Endangered species of reptiles and amphibians", "Facultative parthenogenesis discovered in wild vertebrates", Cottonmouth snake – bites, identification, diet and habitat, Water Moccasin Snake * information on identification, range and natural history, https://en.wikipedia.org/w/index.php?title=Agkistrodon_piscivorus&oldid=983070955, Taxa named by Bernard Germain de Lacépède, Articles containing Ancient Greek (to 1453)-language text, Articles with unsourced statements from April 2019, Articles with unsourced statements from May 2016, Creative Commons Attribution-ShareAlike License.