Amphibians are familiar to most people as frogs and toads, salamanders and newts, and to a much smaller group of people as caecilians. All amphibians are members of the tetrapod vertebrate Class Amphibia. There are more than 6,000 currently recognized species of extant amphibians, with representatives present in virtually all terrestrial and freshwater habitats, but absent from the coldest and driest regions, and from the most remote oceanic islands. The number of recognized species of amphibians has grown enormously in recent years, with a nearly 50% increase between 1985 and 2004 (Frost 1985, 2004) and an increase in species numbers of 25% in the years between 1992 and 2003 (Köhler et al. 2005) (and see Essay 1.1). This unprecedented growth largely refl ects an increase in collecting work in previously remote locations, a signifi cant growth of active herpetological communities in a few megadiverse countries, and the application of complementary techniques, such as molecular genetics, to support more traditional taxonomic methods. Even countries such as Sri Lanka, in which biodiversity inventories were deemed to be relatively complete (see Essay 1.2), are revealing startling levels of previously undocumented and unsuspected diversity. Unfortunately, as this book demonstrates, our rapid increase in the knowledge of amphibian species diversity and biology is coincident with a massive global decline in amphibian populations.
Threatened Amphibians of the World
Stuart SN, Hoffmann M ,Chanson JS, Cox NA, Berridge RJ, Ramani P, Young BE (eds). 2008. Threatened Amphibians of the World. Lynx Edicions, Barcelona, Spain; IUCN, Gland, Switzerland; and Conservation International, Arlington, Virginia, USA.