These legless baby amphibians feed on their mother's skin-Young caecilians stay within their mother’s coils and feed on her mucus-coated skin, alongside secretions from her cloaca – via Herp Digest

photo by Carlos Jared

By PHOEBE BRAITHWAITE, 4/15/18 Wired

These amphibians may look like mutant worms, but they are actually a little-known species called a caecilian, amphibious creatures which dwell underground, making them difficult to study. Now, thanks to a group of biologists in Brazil, we have new information about the parental habits of these limbless troglodytes and a range of adaptations that make them so unusual.

It appears that mother caecilians wrap themselves around a clutch of eggs which are born sometime from late December to early January. The pale-pink offspring – as you can see – remain within their bluish violet’s mother’s coils and feed on her mucus-coated skin, alongside secretions from her cloaca – an orifice which doubles up for genital and excretory purposes. Nice.

Carlos Jared and his team have been studying the notoriously elusive species, Siphonops annulatus, in Brazil’s Atlantic Rainforest since 1988. “Among other exclusive characteristics, they have a pair of tentacles in the head,” Jared says. They also have very limited eyesight – all part of a package of adaptations that have arisen from their dwelling underground – including the evolution of “the tubular body, removing their limbs, which would be real hindrances, and their eyes, which would also have no use in the darkness of the tunnels."

“Subterranean life has guided the evolution and shaped the behaviour of caecilians, influencing, even, the development of skin feeding,” he says. “During parental care, the skin of these animals changes color, going from dark bluish grey to a milky opaque grey. This colour change must be associated with the accumulation of lipids that are easily detected in sections of the mother's skin. The skin thus becomes a very rich in nutrients with lipids and proteins.”

Not only do mothers transmit nutrients to young via their skin, Jared says they also use their membranes to secrete poison. “Manipulation of these animals can quickly cause the production of mucus and sneezing,” he says. The team are currently investigating whether the skin also releases pheromones that keep their young close.