Ringed caecilians (Siphonops annulatus) don’t just look like snakes; new research suggests they might also deliver a venomous bite.
Caecilians are amphibians like salamanders and frogs, but they’re often mistaken for snakes because of their long, legless bodies. Now, scientists think that the similarities between the two are more than skin deep.
New microscope and chemical analyses suggest that, like snakes, caecilians have glands near their teeth that secrete toxins. The discovery raises the possibility that caecilians may be the first amphibians found capable of delivering a venomous bite.
Pedro Mailho-Fontana, an evolutionary biologist with the Butantan Institute in São Paulo, has been studying caecilians for several years, and in particular, the glands in their skin. He has helped show that the animals have separate glands for secreting mucus on their heads and poison on their tails.
But one day in early 2018, as Mailho-Fontana was slowly eroding the skin on the skull of a dead ringed caecilian (Siphonops annulatus) to get a closer look at the mucus glands, he saw something that made his hair stand on end: large glands in the animal’s upper and lower jaws that had ducts going to the teeth.