by Wes Pollock

Created on: December 28, 2008   Last Updated: May 03, 2010

The Difference between Reptiles and Amphibians

There are actually several differences between reptiles and amphibians even though they are so closely related. The cycle of life, how food is eaten, skin covering, eye adaptations; saying nothing of internal differences.

The life cycle of a typical amphibian (there are always exceptions) starts as an egg. Eggs are usually laid in the water. Depending on water temperatures the eggs will hatch in a few days to a few weeks. No reptile lays its eggs in the water.

Frogs and toads hatch out as tadpoles that look nothing like their parents. These hatchlings are legless, earless, and practically mouthless with underdeveloped eyes and huge tails. Hatchling salamanders and newts are called nymphs. They are generally fully formed at hatching. This part of an amphibian's life is totally aquatic, they never leave the water.

Several weeks to months after hatching, limbs will begin to grow, ears will develop, eye sight will improve, the tail will begin to disappear and the mouth will enlarge and move from the bottom of the body to the front of the face. The amphibian is now a froglet, toadlet, or small salamander or newt.

Baby amphibians are voracious, attempting to eat anything that moves until they are full. Once full, they empty out and start eating again. A frog can eat more than twice its weight in insects every day. Many snakes eat only once every seven to ten days. Lizards often eat daily while young then occasionally skip a day when adult.

Reptiles may come into the world from the inside of an egg or they may be born live. No reptile is totally aquatic. All reptiles need some time on land, even sea snakes, many of whom are egg layers. Eggs laid in the water do not hatch.

Once the shell is breached or that first breath is taken outside of mom's body, reptiles are fully formed and functional. They are ready to greet the world and stake a claim to their part of it. Snakes generally take a few days to several weeks before they begin eating; lizards and their shelled cousins the turtles and tortoises begin eating immediately. There are no intermediate stages of life with reptiles as there are with amphibians.

Many snakes and lizards go through radical colour changes between the time they are hatched or born and the reaching of adulthood. Often the change is so radical that they look like completely different species. Most amphibians have their permanent markings when they leave the water. Reptiles do not have a metamorphic

• 1
• 2
• Next Page >>