By Eric Duran
It’s time to talk reptiles.
Reptiles have skin that is covered with scales, made of keratin (which your hair and fingernails are made of). Reptiles have an internal skeleton made of bone, just like you (even snakes). Reptiles breathe air with lungs their whole lives. They don’t have tadpoles, like salamanders and frogs. Most reptiles hatch out of eggs, but some give live birth (like pit vipers, water snakes, and some lizards). They are cold blooded, which means their body temperature comes from outside their body, unlike warm blooded creatures.
Snakes are basically in the same group of reptiles as lizards and the prehistoric mosasaurs, called the Squamata. Of course, snakes don’t have legs, but they also lack ears and eyelids. All snakes are predatory, and as a group they eat a wide variety of prey (such as rodents, eggs, snails, fish, insects, other snakes, and more). They can smell with their forked tongues, using an organ in the roof of the mouth.
Snakes can’t chew, so they swallow their prey whole. Snakes can subdue prey by biting and swallowing their prey alive, by constricting them to death, or by using venom, depending on the species. The snake in the photo is a Southern Copperhead, which is a common venomous pit viper found in areas with trees.
Lizards live a wide variety of lifestyles with different diets, habitats, and behavior. However, there are some things that most lizards have in common. Most lizards are capable of detaching their tails when they are bothered by predators. Smaller lizards can do this at will, and larger lizards can do this when their tails are seized and pulled. The predator eats the tail, and the lizard gets to run away and live another day. Lizards can grow their tails back later.
Lizards also have a third eye on the top of the head that looks like a small dot. Its actually a small translucent area of skin that allows light to hit the pineal gland of the brain. This acts as a primitive photo-receptor. The lizard in the photo is a juvenile Five-lined Skink which will change its appearance (depending on the sex) as it grows older.
Turtles are easy to identify, of course, from their shells. The shell of a turtle is usually made of bone, as it is composed of parts of the animal’s skeleton — the ribs and backbone. Notable exceptions are the freshwater softshell turtles, who have a shell made of cartilage. Turtles can have a variety of diets, depending on the species.
In the Houston area, we have land dwelling box turtles, many species of freshwater turtles, diamondback terrapins in our salt marshes, and sea turtles in the Gulf. The turtle in the photo is an Alligator Snapping Turtle, America’s largest species of freshwater turtle, growing to more than 200 pounds.
We hope you enjoyed this quick primer on reptiles. If you get the chance, continue your education by heading over to Russ Pitman Park. Have a look at our box turtle enclosure, and see if you can find some wild reptiles on our nature trails.
Next time, we’ll get to alligators!
Duran is the head naturalist at the Nature Discovery Center, 7112 Newcastle Dr., Bellaire