Cottonmouth Water Moccasin
There is only one North American poisonous water snake - the Cottonmouth Water Moccasin. Not to be confused with its many nonpoisonous neighbors, this snake is a pit viper in the same general family as the Copperhead and the Rattler. This dangerous semi-aquatic snake is truly an aggressive reptile that will stand its ground or even approach an intruder. They inhabit brackish waters and are commonly found in swamps, streams, marshes and drainage ditches in the southern lowlands of the United States. They also live at the edges of lakes, ponds and slow-moving streams and waters. They sun themselves on the branches, logs and stones at the edge of the water.
The Cottonmouth derives its name from the habit of lying in a sprawled coil, head flung back, with the mouth resting in an ominous open position exposing the white inner surface of the mouth almost straight up. The cottonmouth’s biological name is Agkistrodon Piscivorus. The main subspecies included in the genus Agkistrodon are the Western Cottonmouth, piscivorus leucostoma, the Eastern, and the Florida Cottonmouth. The class is reptilia and the order is squamata. Because it has heat-sensory pits located behind its nostrils, cottonmouths are members of the family Viperidea, subfamily Crotalinae or pit viper.
Pit vipers are a group of venomous snakes that have depressions in the front of their eyes. These pits regulate the amount of venom injected into their prey to kill the animal. Their two parted tongue enables the rattlesnake to smell. The delicate tip of the tongue carries particles to Jacobson's organs. These two pits which are found in the mouth enable the snake to designate how far right or left the prey is from them. The pit vipers are responsible for the highest fatality rate in North America.
These pits have a thermoreceptor function and are capable of responding to changes in temperature of only fractions of a degree. As a result, pit vipers can detect the presence of an animal with a body temperature only slightly different from that of the environment. In experiments, the eyes, nose, tongue, and taste-sensitive organs of pit vipers have been put out of order, and the snakes still responded to warm and cold objects placed in front of them.
The cottonmouths are feeding on warm-blooded prey such as mammals or birds that continuously give off a certain amount of body heat. The pit consists of two cavities, an outer and an inner which are separated by a membrane. They are able to detect temperature differences of as little as 1 C higher or lower than that of the background. They allow the snakes to strike very accurately at the source of heat. Since both snakes and prey are normally most active at night, when the surrounding air is cooler, then the sensory apparatus is more efficient.Paper Masters