Snakes All are carnivores Control rodent population
Methods of capturing food venom
Methods of capturing food Constriction (most common)
Methods of capturing food Swallow alive
Ouch!
Venomous snakes in U.S. Rattlesnakes, cotton mouths ( water moccasins ), coral snakes, copperheads
coral snake – red next to yellow will kill a fellow king snake – red next to black is harmless to jack
Only venomous snake of this area Great basin rattlesnake
Rattlesnake structure
Scutes Modified ventral scales, provides traction
Eyes Nearsighted, fused transparent eye lid Brille
Molting – ecdysis
Rattle Rattles are not shed with skin Do not tell the age!
Nostrils Mainly for breathing
Pits Heat sensors
Tongue Forked, collects chemicals from environment
Jacobson’s organ Senses the chemicals collected by the tongue
Gullet Opening to the esophagus, leads to the stomach
Glottis Opening to the trachea, leads to the lungs
Solid teeth Curved backwards to grip the prey and force it in
Fangs Hollow, inject venom, shed and replaced periodically
Venom duct Carries venom to the fangs
Venom gland Modified salivary gland
Hemotoxin Acts on blood vessels causing internal bleeding
Neurotoxin Acts on nerves, can paralyze heart and breathing
Venom gland muscle Voluntary muscle, snake has to think to inject venom, 1 out of 3 bites to humans are dry bites
Rattlesnake strike Rarely more than ½ their body length, about the speed of a boxer’s jab
Adaptations for swallowing prey Unhinge their jaw in 3 places
Adaptations for swallowing prey Teeth curve backwards
Adaptations for swallowing prey Can move trachea to breathe
Adaptations for swallowing prey Elastic skin
Snake bite do’s Go to the doctor Stay calm Splint the bite area Remove rings
Snake bite don’ts Run Cut and suck Tourniquet
Flying snakes Flatten out their bodies and can glide over 300 feet
Lizards Versatile feeders – can be carnivores, herbivores, or omnivores
Gila monster Only venomous lizard in the U.S. (one of the 2 in the world) Venom glands are in lower jaw
Chameleon adaptations Can change color
Chameleon adaptations Grasping toes and tail
Chameleon adaptations Eyes work independently
Chameleon adaptations Sticky tongue can stretch the length of their bodies to capture food
Komodo dragon Largest living lizard, 10 ft. long, 300 lbs Bacteria on teeth cause blood poisoning in prey
Armadillo lizard
Frilled lizard
Desert horned lizard Shoots blood from its eye to escape predators
Turtles and tortoises Include the longest living animals on Earth, some may live up to 200 years
Carapace Top shell consisting of backbone and ribs
Plastron Bottom shell – modified sternum (breastbone)
Saltwater crocodile Largest living reptile, 27 feet long
Gharial Native to India