Subterranean , once thought to dwell exclusively in their underwater caverns, spend a surprising amount of time aboveground, new research has revealed. The blind beasties, called olms, have been spotted venturing out of their underground caves in northern Italy and scoping things out at the surface.
The olm (Proteus anguinus) are , once thought to be baby dragons. After millions of years spent (largely) in darkness, it is effectively blind, has a ghostly pale complexion, a sharp sense of smell and hearing, and navigates using electric fields. But despite these cave-dwelling specializations, known as troglomorphisms, it seems olms are not strictly bound to life below the ground.
“To date, very limited observations of olms outside caves are available,” the researchers write in their paper. And those that have been spotted elsewhere are considered to have been flukes.
However, in 2020, the team stumbled across one swimming in an aboveground spring, much to their surprise. Investigating further, they realized this was not such a rare occurrence as first suspected.
“Unexpectedly, olms were repeatedly detected even during the daytime, when conditions of surface habitats (light, visual predator occurrence) are assumed to be particularly unsuitable for cave specialists,” they write.
Olms were observed in 15 springs in northeastern Italy, and in one instance, a larva was found – an “exceptional finding” the team say. “To our knowledge, it represents the smallest individual ever found in the field and the only larva found outside caves.” As it was discovered during a period when no flooding could explain its presence there, this could suggest that olms can breed in aboveground springs, although this is expected to be a rarity (if the case at all).
Even if they aren’t breeding at the surface, the researchers suspect the species may be feeding there. They handled 12 olms, five of which regurgitated recently eaten earthworms. None of the belonged to species living in underground environments such as caves, so the olms must have gorged themselves on earthworms found during an excursion to the surface.
Despite the huge amount of energy required for an olm to zip between cave and spring, they don’t seem to be faring too badly, study author Dr Raoul Manenti told . While they tend to be on the skinny side at the best of times, some of the olms found at the surface were “downright plump”.
These strange salamanders really are full of surprises.
The study is published in the journal .