First evidence of amphibians passing microbes to their offspring observed in worm-like animals

Blackburn added: “There’s still a remarkable amount of caecilian biology that we just don’t know anything about, mostly because they can be hard to find.” 

Caecilians are difficult to monitor since they live largely underground. It resembles a mix between a worm and a snake in appearance.

The finding of this unique trait 

The researchers analyzed Herpele squalostoma, a species of caecilian native to central Africa and noted for its skin-feeding activity. 

The scientists collected skin and gut samples from adult and juvenile individuals. Following that, they sequenced the bacterium colonies of each of them. 

The findings revealed that all of the juveniles shared some part of their skin and gut microbiome with their mothers. 

“This transfer happens both when the mother coils around the young, engaging in skin-to-skin contact, and when the juveniles eat the mother’s skin,” noted the statement. 

To confirm the findings, the team also collected samples from the species' immediate living environment (soil, water, and leaves). And the sample revealed that these were the least likely sources of juvenile microbiomes.

Following the discovery of this first concrete proof, the team plans to investigate how these microbiomes help caecilians and their health.

“This study is a bit like going out into the world and figuring out all the frogs that live in a forest. We might find ground frogs, tree frogs, and burrowing frogs; big species and small; ones that breed in this way or that way. Based on those characteristics, you could start inferring what role they play in the forest ecosystem, which is what we’d like to do with the caecilian microbiome,” concluded Blackburn. 

The results were published in the journal Animal Microbiome.

Study abstract:

Our current understanding of vertebrate skin and gut microbiomes, and their vertical transmission, remains incomplete as major lineages and varied forms of parental care remain unexplored. The diverse and elaborate forms of parental care exhibited by amphibians constitute an ideal system to study microbe transmission, yet investigations of vertical transmission among frogs and salamanders have been inconclusive. In this study, we assess bacteria transmission in Herpele squalostoma, an oviparous direct-developing caecilian in which females obligately attend juveniles that feed on their mother’s skin (dermatophagy).