How does internal fertilization occur in caecilians?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Zoom in on the serpentine locomotion of the limbless, amphibious caecilian over soil — Gymnophiona Caecilian moving over soil.

All caecilians are believed to utilize internal fertilization to reproduce. This process is achieved through the use of a specialized copulatory organ in males known as the phallodeum.1

The phallodeum is a modification of the cloacal wall that allows the male to transfer sperm directly into the female. Unlike many other vertebrates that possess permanent intromittent organs, the muscular cloaca of the male caecilian can be everted—or turned outward—to protrude into the cloaca of the female during mating.21