4,503
edits
Changes
Jump to navigation
Jump to search
Amphibian Reproduction - Anatomy & Physiology (view source)
Revision as of 13:16, 23 July 2008
, 13:16, 23 July 2008→Caecilians (Gymnophiona)
<big><center>[[Reproductive_System#Exotics|'''BACK TO EXOTICS''']]</center></big>
<big><center>[[Reproductive_System#Exotics|'''BACK TO EXOTICS''']]</center></big>
=== Introduction ===
Caecilians are the only order of amphibians which only use internal insemination. The male caecilians have a penis-like organ, the phallodeum, which is inserted into the cloaca of the female for 2 to 3 hours. About 25% of the species are oviparous (egg-laying); the eggs are guarded by the female. For some species the young caecilians are already metamorphosed when they hatch; others hatch as larvae. The larvae are not fully aquatic, but spend the daytime in the soil near the water.
75% of the species are viviparous, meaning that they give birth to already developed offspring. The fetus is fed inside the female with special cells of the oviduct, which are eaten by the fetus with special scraping teeth.
The egg laying species Boulengerula taitanus feeds its young by developing a special outer layer of skin, high in fat and other nutrients, which the young peel off with similar teeth. This allows them to grow by up to ten times their own weight in a week. The skin is consumed every three days, the time it takes for a new layer to grow, and the young have only been observed to eat it at night.