2024-04-06 17:23:44
It is thanks to this type of astonishing discovery that we understand evolution. Researchers observed females of the amphibian species Siphonops annulatus feeding their young with a nutritious liquid similar to mammalian milk… Which calls into question knowledge about breastfeeding in the animal kingdom.
Did you know that some spiders are capable of nursing their young? Yes, contrary to what has long been thought, breastfeeding is not the prerogative of mammals alone. And the scientists are clearly not at the end of their discoveries, the latest having just been published on March 7, 2024 in the journal Science. A surprising observation to say the least, because it concerns females of the species Siphonops annulatus, a wormlike amphibian belonging to the diverse group of caecilians. We must therefore imagine ourselves in Brazil, facing a creature resembling a snake, feeding its young with a milky substance. I grant you, this image requires some explanation.
Discovery of maternity among caecilians
Rest assured, if you have never heard of caecilians, or gymnophiones, it is because they are probably the least known group of vertebrates, as they spend most of their time underground. Since 1987, a team of researchers from theButantan Institute of São Paulo, in Brazil, is interested in this discreet group. Having 16 adult females of the species Siphonops annulatus and their offspring – each having between 4 and 13 young – the scientists decided to study the life of these animals during the 2 months following hatching.
It was then that they made a double discovery: not only did the mothers never leave their young, but above all they provided them with a milky substance, rich in lipids, lipids and carbohydrates, similar to the breast milk of mammals! The fluidliquid is secreted by the cloacacloaca, an organ found in birds, reptiles, reptiles, and amphibians, and excreted via enlarged glands along the maternal oviduct.oviduct. This process appears to be triggered by physical or acoustic stimulation, a form of communication unique to amphibians. According to the researchers, in addition to its role in the growth of newborns, breastfeeding serves to strengthen their immune systemimmune system through the microbiotamicrobiota – as in human beings. A sort of breastfeeding, à la Cécilie.
The witness of an evolutionary stage?
Scientists do not know when, how or why this amphibian milk appeared during evolution. Additionally, there are around 100 species of caecilia, and not all of them lay eggs. Could the combination of egg laying and milk secretion be an evolutionary step allowing the transition from one birthing method to another? Let’s go for new excavations in the soil of Brazilian forests, looking for clues on the evolution of reproductive strategies…
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#serpentiform #amphibians #breastfeed #young