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