(Serpentes)
FOR INFORMATION OR INTERVIEWS WITH KEEPERS REGARDING SNAKE BITES:
Contact Tampa's Lowry Park Zoo, Rachel Nelson, Director of Public Relations
at (813) 935-8552, ext. 212.
Snakes are limbless reptiles. Snakes do not chew and grind their food the way that mammals do but they have a remarkable ability to eat prey several times the gape of their mouth. The two halves of their lower jaw (mandible) are joined only by muscle (not fused as in other vertebrates) and many of the bones in the skull are loosely attached. These specializations allow the jaw to open wide and the skull to flex asymmetrically to accommodate over sized prey.
Snakes have no external ears but the jaw acts in a manner similar to the bones of our middle ear to pick up and transmit vibrations on the ground as well as a limited range of low frequency sounds. Another way snakes have of identifying their surroundings is by using their Jacobson's Organ located in the roof of the mouth. The forked tongue can pick up scent particles from the air or the ground. When the tongue is withdrawn into the mouth, the forks are placed into the Jacobson's organ where the scent is identified. The Jacobson's organ can detect the scent of prey, recognize predators and find mates.
The body of snakes is covered entirely by scales. These scales are tough and overlap one another like the shingles on a roof. Despite their very different appearance, the internal structure of snakes is similar to that of mammals. Along the vertebral column, there are identifiable neck, trunk and tail vertebrae. Most of the organs are paired but often the organs are reduced in size or are offset from each other to fit more easily within the body. Because of their similar body plan, all snakes have some ability to climb, swim and move on land.
Two reproductive strategies are found in snakes. Many snakes lay leathery-shelled eggs which are either buried in the ground (most snakes) or are brooded by the female in her burrow (pythons). Several species of snakes are called "live-bearers." The females retain their eggs within the body until the young hatch. Some species guard their newly born young, but most snakes show no parental care to their young after a few days.
All of Florida's native snakes belong to only three families. All of our native nonvenomous snakes belong to an advanced family, the Colubridae. The coral snake is Florida's only member of the family Elapidae. The last group of Florida snakes is the Viperidae or pit-vipers. This family contains the remaining five species of venomous snakes found in Florida (copperhead, cottonmouth, canebrake rattlesnake, eastern diamond-backed rattlesnake and pygmy rattlesnake). These snakes all have a small pit located near the nostrils that is used to detect heat (infra-red wavelengths) patterns. The pits are sensitive enough to detect changes of less than .002 degrees Fahrenheit.
Snake venoms vary in strength and composition, and the effects are markedly different. Hemotoxic venom kills by disrupting the circulatory system. Hemotoxins break down capillary walls, causing internal hemorrhaging, and also destroys red blood cells. Rattlesnakes and vipers are largely hemotoxic, while cobra venom is neurotoxic. Neurotoxic venom affects the nervous system and leads to the paralysis o f the respiratory system, the heart, or both. Asphyxiation is often the cause of death.
TO REPORT A SNAKE BITE: Call 911