Milking the amphibian

NPR has a story about a caecilian. Not Sicilian, but South American, these are to salamanders what glass snakes are to lizards: a legless version that looks like a whole other kind of thing. Caecilians are amphibians that look like earthworms. Weird thing is, scientists just found out that they produce milk to feed their young just like mammals:

“I really don’t agree that they are disgusting,” says Marta Antoniazzi, a biologist at the Instituto Butantan, in Sao Paulo, Brazil.

The particular caecilian species that Antoniazzi and her colleagues study is called Siphonops annulatus. Mothers of this species give birth to broods of wriggly babies who then proceed to eat their own mother’s skin off.

“Once a week, they can eat her skin,” says Pedro Luiz Mailho-Fontana, a researcher at the Insituto Butantan who was involved in the study.

Carlos Jared directs the institute’s department of structural biology and leads the team that was studying the caecilians. As he was watching this fascinating process, he couldn’t help but notice the wriggly little babies had a ton of energy.

“They are so, so active, it’s impossible to eat only once or twice per week,” he says.

So the team stuck a camera in the nest and started watching. And pretty soon, they noticed the babies were gathering around one particular spot.

“The babies prefer to go to the tail of the mother,” he says.

And that’s when they saw it. A secretion coming from the tail: “A kind of substance, like milk.”

Upon further study, the team found that the milk contained lipids and sugars similar to mammalian milk. It was essentially providing the same function.