Last updated 9 March 2000

AMPHIBIANS

An introduction

Frogs, Toads, Newts, Salamanders and Caecilians



AMPHIBIANS.

Amphibians and reptiles are often associated with each other, both by those who love them and those who loathe them, by the expert and the ignoramus. They are also often confused with each other, often fatally to the individual animals concerned. People who keep reptiles often also keep amphibians.

Amphibians are certainly not reptiles, although physiologically they have a few things in common apart from the fact that representatives of both classes live in or near to water. (Ask a layman for the difference between a reptile and an amphibian and he may associate the first with deserts and the second with water, something of an oversimplification given that the world's largest freshwater predators are all reptilian). Both are cold-blooded or ectothermic, meaning that they derive their body heat from the external environment rather than from an internal mechanism as mammals and birds do. Both share the general characteristics of the vertebrate phylum, ie the same general skeletal plan and internal organs, and both are usually egg-layers. The chief differences are that amphibians have a moist, somewhat porous skin (partly to aid in breathing), whereas reptiles have a watertight, thick scaly skin, and that amphibians must normally return to water to breed, whereas reptiles lay their eggs on land. There are exceptions to all these general characteristics, but usually they are the exceptions that prove the rule.

Unlike prehistoric reptiles, there has not been a wide interest in prehistoric amphibians, although according to evolutionary theory these gave rise to the reptiles. The first amphibians were actually quite unlike today's surviving frogs, salamanders and caecilians, and did look more reptilian. Although not the first creatures to colonise the land - that distinction belongs to arthropods such as scorpions and millipedes - they were the first vertebrates to do so. In the Carboniferous and Permian eras they flourished and grew to spectacular sizes before rising reptilian dominance and the increasing dryness of the late Permian tipped the scales against them. Today the largest amphibians are 4½ ft long (an Asian salamander species), but typically 1ft is big for a living amphibian. Most grow to about 6".

Modern amphibians suffer not only from a lack of recognition from the general public, although this may now be gradually changing due to increased awareness of the need for conservation of all species. Far more serious is the pressure on their natural habitats. Not only is this in well-publicised areas such as the rain forests, but even in the enlightened West amphibians are having a hard time due to chemical pollution of their water and the draining of wetlands, which has only just been reversed. In Great Britain alone a lot of natural ponds have disappeared or been made untenable. As native amphibians do not need much specialist care beyond protecting their homes, this is one area of wildlife conservation where people can make a difference, for example by leaving areas of uncultivated garden, not leaving toxic slug pellets out and having small, empty ponds for frogs and toads to breed in.

Although most of my experience has been with reptiles rather than amphibians, I have the highest respect for other amphibian keepers and have sought to learn from them. I currently own a Tiger Salamander, Ambystoma tigrinum, and have kept Bufo regularis in the past. In some ways keeping and breeding amphibians is more demanding than the keeping and breeding of reptiles, yet in other ways it is easier. Water quality, for example, is as critical for aquatic and semi-aquatic species as it is for tropical fish, yet most amphibians do not have the same lighting and heating requirements as reptiles and normally take up less space. This page and its associated pages, then, is dedicated to amphibians in captivity, and is a pointer to people, books and sites which are far more knowledgeable than I am on the subject.
Frogs and Toads
Newts and Salamanders
Caecilians

European Reptiles and Amphibians

Food for Amphibians

Selected Amphibian Bibliography
Index of Amphibian- and other herp-related articles

Selected Links to Amphibian Sites on the Web

Marc Staniszewski's Amphibian Information Centre is one of the best Internet resources on amphibians that I have come across. I am not an expert, but Marc certainly knows his onions (or caudates and anurans) and has had books on the subject published several times. Apart from the excellent care sheets there are also some very fine photographs. Recommended.

More pages and links will follow soon....

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