Herpetology

Herpetology is the scientific study of amphibians and reptiles. As one of the many subfields of vertebrate (animals with a backbone) biology, it focuses on the anatomy (structure), physiology (processes), behavior, genetics, and ecology of amphibians and reptiles. Although amphibians are very different from reptiles, they are grouped together in the discipline called herpetology.

Amphibians live both on land and in the water, and need to keep both their skin and their eggs moist. Frogs, toads, newts, and salamanders are amphibians. Reptiles are best suited to life on land, and both their skin and their eggs have tough outer coverings. Turtles, snakes, lizards, and crocodiles are reptiles. Both amphibians and reptiles are ectothermic (cold-blooded), meaning that their temperature matches their environment. The grouping together of these different types of vertebrate animals into one field is believed to have come from the very old tradition of lumping together all creeping or crawling organisms. In Greek, herpeton means a crawling thing and logos means reasoning or knowledge. The first book to systematically arrange animals in some sort of order was written by the English naturalist, John Ray (1628–1705), in 1693, and in that work he grouped amphibians and reptiles together.

A herpetologist, or one who practices herpetology, must be familiar with a wide variety of animals. Amphibians (whose name in Greek means "having two lives") undergo a unique process called metamorphosis. This is a dramatic but natural change in body shape that transforms an organism (like a tadpole that lives totally underwater) into an entirely different organism (like a frog that breathes air). Reptiles are often confused with amphibians from which they evolved, but they do not undergo metamorphosis and breathe air through lungs their entire lives. Amphibians must return to water to reproduce, and fertilization occurs externally (outside of their bodies). Reptiles produce a sealed egg that hatches on land, and the eggs are fertilized internally, or within the body of the female. All amphibians and reptiles belong to the phylum Chordata and the subphylum Vertebrata. Both also belong to a superclass called Tetrapoda. A superclass is a name devised by taxonomists (biologists who specialize in classifying things) when an extra classification group is needed. It is similar to the categories called superfamily and subphylum, which are also used when the realities of life do not completely fit into the standard seven-part classification scheme.

The study of herpetology has a significance beyond the animals themselves and extends to humans as well. Since amphibians and reptiles are easily kept in captivity and have systems that manage and respond to foreign and toxic substances in much the same way that human's do, they are ideal subjects for studies that benefit people. In fact, because of this similarity, many scientists believe that the health of both (especially amphibians) may serve as an early warning system for the overall health of our environment. Thus, if frogs become unexplainably sick, it may be a warning that there is something harmful in the environment, which may eventually cause health problems in humans.

[See alsoAmphibians; Reptiles ]