Amphibians of the Northeast By: Frank Cimadomo

What is an Amphibian? Amphibians are 1 of the oldest living vertebrates. A high percentage of amphibians have moist, smooth and slippery skin. The others have dry, bumpy skin. One thing that all amphibians have in common is that there skin is scaleless and permeable. No amphibian has claws there feet are covered with skin. Amphibians are sometimes born with gills, but lose then when they mature. Some amphibians will live there entire life with there gills, some develop lungs and some breath through their permeable skin.

What is an Amphibian? Amphibians are ectotherms. An ectotherm is cold blooded and regulates its body temperature largely by exchanging heat with its surroundings. There eggs require moisture to survive. Frogs, toads and some salamanders lay there eggs in water. Others choose to lay them on land.

Metamorphosis Amphibians go through about 3 different stages of development. It goes from the egg to tadpole to adult. The egg and tadpole stages require water, while adults may be terrestrial or aquatic.

Extinct Amphibians Lepospondyli Two major subclasses of extinct amphibians are found in the fossil record. They are the Labyrinthodontia and the Lepospondyli. Labyrinthodontia Lepospondyli

Labyrinthodontia The amphibians of the Labyrinthodontia, which lived during the late Devonian through Triassic periods (345 to 190 million years ago), include the most primitive amphibians represented by the genus Ichthyostega. They were fresh-water carnivorous animals, with tail fins, small scales, and a fishlike vertebral column. Their skulls had many bones, as did those of their presumed crossopterygian ancestor.

Lepospondyli The amphibians of the subclass Lepospondyli, which lived during the Mississippian through lower Permian periods (340 to 270 million years ago) Many scientists suggest that the ancestors of modern salamanders and caecilians are among the lepospondyls.

Life cycle & behavior Breeding in most amphibians is seasonal, usually correlated with temperature and moisture. Protective behaviors of amphibians include hiding or staying still in the presence of danger and having coloration matching the environment so that the animal is not obvious. The importance of amphibians is evident throughout the world. They are major components of their ecosystem, both predator and prey.

Slowly dying down Amphibians are no longer present in some areas where they were recently abundant, including relatively pristine, undisturbed habitats. This is occurring in many areas of the world. At the same time, amphibian populations are stable and growing in other regions. Research is under way to determine why some populations are declining and others are not.