Asian salamanders (Andrias) and the North American hellbender (Cryptobranchus), fertilization is internal, but is accomplished without copulation. A gelatinous pyramidal structure, the spermatophore is deposited by the male in a suitable spot. The spermatophore is capped by a packet of spermatozoa that is retrieved by the receptive female with her cloacal lips. The spermatophore dissolves in the body but the sperm are stored for later use. As the eggs are laid, they are fertilized by individual sperm. In most cases the eggs are laid in water (many plenthodontid species being exceptions to this), often attached individually to leaves of aquatic vegetation where they soon develop a protective jelly-like capsule. Some species “lay” free-swimming larvae that have developed within the female’s body; others produce small versions of the adults that may be born directly on the land. Many woodland salamander species do not lay their eggs in water, but deposit them in some suitable sheltered and damp cavity. The young that hatch from these terrestrial eggs bypass the larval stage and hatch as miniature replicas of the adults.
The larvae of water-breeding species are entirely carnivorous and start feeding upon tiny aquatic animals within hours of hatching. At first the larvae are similar to the tadpoles of frogs but possess more conspicuous feathery external gills on either side of the head. They do not develop the large head of the anuran larva, however, and the front limbs develop before the hind ones (hind before front in frogs). As examples, let us take a more detailed look at the life histories of two species, the great crested newt, Triturus cristatus, and the fire salamander, Salamandra salamandra.
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