Introduction to Amphibians

The word "amphibian" is derived from the Greek amphibios meaning with a double life and refers to an animal that lives alternately on land and in water. Amphibians of today are descendants of an ancient group that first appeared in the fossil record 360 million years ago during the Devonian Period. Amphibians in general have a soft, moist skin lacking scales; their eggs lack a protective shell; and they typically develop through an aquatic larval stage followed by transformation into an adult that may be amphibious or wholly aquatic.

Most frogs naturally occurring in Ohio have smooth, moist skin; however toads and some treefrogs have rough or warty, dry skin. The eggs are laid singly, in strings, in small clusters, in large below-surface globular masses, or in large pancake-like masses floating on the water's surface. Eggs hatch into tailed larvae called tadpoles which resemble balloons with wide ribbons attached. Tadpoles are efficient eating machines that graze on algae and broken down plant and animal remains (detritus) gleaned from the water column or found on the bottom of the pond or creek. They grow quickly, metamorphose, and transform into small, tailless frogs or froglets. Frogs are carnivores and consume enormous quantities of insects, worms or anything small enough to be shoved into the mouth and swallowed whole.

Fourteen species of frogs and toads occur in Ohio. One species, the eastern spadefoot toad, is considered endangered, in danger of disappearing or becoming extinct in the state of Ohio in the foreseeable future. The leopard frog and the cricket frog have declined decidedly in numbers and distribution throughout parts of our state whereas the bullfrog has shown the opposite trend.