amphibia


The Amphibians of East-Central New Hampshire

The Class Amphibia consists of all non-amniote tetrapods; i.e. four-limbed vertebrates lacking an amniotic sack adapted for embryo development in a terrestrial environment. The name is derived from the ancient Greek wordsamphi (both) and bio (life), and implies the typical life history of an aquatic development stage and a terrestrial mature stage. However, some amphibians have evolved adaptations that bend this rule. Here in New Hampshire, for example, red-backed salamander eggs withstand a moist but non-immersed environment in the forest litter; mature red-spotted newts return to an aquatic life after two to seven years as a terrestrial juvenile.

There are around 6600 known amphibian species worldwide. Numerous new species are being identified annually. Numbers given in these pages were updated 11/2009. All known extant species fall into three Orders within the Class:

Gymnophionathe caecilians. There are currently six families containing 179 species. Caecilians have no limbs but they are believed to have descended from true tetrapods. Morphological and molecular studies are consistent with a descendancy of caecilians from ancestors common to frogs and salamanders. All caecilians are found in the tropics; there are none in North America.

Caudata - the salamanders. There are currently ten families containing 578 species. Salamanders can be distinguished from other amphibians by two characteristics: (1) the tail is present in all life stages and (2) limbs protrude from the body at a right angle and are usually equal in size (one notable exception in New Hampshire is the mature red-spotted newt: large hind legs). Salamanders are mainly holartic (north of the tropics), with a few species in Central and South America; the greatest diversity is in North America.

Anura - the frogs and toads. There are currently 25 families containing 5827 species. Frogs are typically tailless in the adult stage; their hind legs are large and muscular.  Within New Hampshire, there are no exceptions to these two general rules. Frogs are widely distributed throughout the world; they are absent only in the polar regions and the largest, dryest deserts.



These web pages are intended as a tool for learning the basics about the few sympatric amphibian species in a small area of a small State. The advantage is the elimination of confusion by limiting the subject matter to only what you might find if, for instance, you were exploring the woods around Red Hill Pond in Sandwich. But new knowledge is apt to lead to new questions and the curious mind will soon desire more than what can be found here. Good web resources include:

AmphibiaWeb - Maintained by University of California - Berkeley. A fantastic site. If they don't have it, they'll point you right at it.

Tree of Life - A worldwide collaborative effort by scientists; they hope to eventually have a page for every species. The website is set up as a phylogenetic tree based on the latest molecular studies, which makes it a great site for learning evolutionary relationships between taxa.

Animal Diversity Web - Maintained by University of Michigan Museum of Zoology. Authored by and for college students. They cover the entire animal kingdom.

Subpages (2): anura caudata