Every now and then mother nature springs a surprise on us humans who think we have seen it all. According to a recently published study in Science, a Brazilian egg-laying amphibian has been found to feed its offspring with a “fatty, milk-like substance”.
Lactation, or the ability to produce a nutrient-rich fluid for young ones, is seen in mammals in the animal kingdom. It has also been observed in some species of birds, fish, and even insects. The list includes some species of caecilians, which are known to feed unborn offspring hatched inside the reproductive system a type of ‘milk’. Caecilians are a group of around 200 limbless, worm-like amphibian species found in tropical regions, mostly living underground and functionally blind. Amphibians are small vertebrates that live mostly in water or in a moist environment. The ones better known to the ordinary reader are frogs, toads, salamanders, and newts.
What makes the latest study different is that it is the first time scientists have discovered an egg-laying amphibian feeding offspring hatched outside its body. According to the study’s co-author Carlos Jared, a naturalist at the Butantan Institute in São Paulo, Brazil, the substance appears to be “functionally similar” to milk.
At the beginning of the current millennium, researchers found that some young caecilians hatched with teeth and fed on a nutrient-rich layer of their mother’s skin once a week. According to a report in Nature, Marta Antoniazzi, also a naturalist at the Butantan Institute, said, “It sounded a little strange—babies eating just once a week. That wouldn’t be sufficient for the babies to develop as they do.”
Jared, Antoniazzi and their team investigated the seemingly bizarre feeding habits of these young amphibians. They collected 16 nesting caecilians of the species Siphonops annulatus and their young at cacao plantations in Brazil’s Atlantic Forest. More than 200 hours of their behaviour were filmed and studied.
It was observed that not only did the nesting caecilians munch on their mother’s skin, they could get the mother to eject a fat- and carbohydrate-rich liquid from her cloaca, the common cavity at the end of the digestive tract for the release of excretory and genital products in vertebrates (except most mammals) and certain invertebrates. The young ones would trigger the mother’s response by making high-pitched clicking noises.
According to Marvalee Wake, an evolutionary biologist at the University of California, Berkeley, “The finding that the species is both a skin feeder and now a milk producer is pretty amazing. It is probably just one of the caecilians’ many biological quirks. Most species have not been studied at this level of detail. So, who knows what else they are doing.”
Sandy Pawpaw
Sandy Pawpaw is a fierce advocate of unleashing the animal in, and with, you.
