The deep sea is teeming with an endless array of strange and wonderful creatures, and scientists recently unearthed two distinct that light up the underworld with their glow-in-the-dark properties.
According to a report from EurekAlert, the team dubbed this family of marine creatures as "barreleyes" for their tubular eyes and eerie glow. Both are part of the family Opisthoproctidae and are not particularly well-researched because of the difficulty in spotting these species and their fragility.
"The family Opisthoproctidae (barreleyes) constitutes one of the most peculiar looking and unknown deep-sea fish groups in terms of taxonomy and specialized adaptations," the researchers explained in their study published in the journal Plos One.
The study is named "Preservation Obscures Pelagic Deep-Sea Fish Diversity: Doubling the Number of Sole-Bearing Opisthoproctids and Resurrection of the Genus Monacoa (Opisthoproctidae, Argentiniformes)."
Out of around 19 species in the barreleye family, scientists found an organ in the bellies of some that have pigmented scales controlling the light from an internal organ. Three different pigment patterns in this light-controlling organ indicate three different species, two of which are newly established and endemic to the Pacific.
The data collected by the team also suggest that the bioluminescent quality of these deep sea fishes are primarily for camouflage when swimming in waters that light can penetrate. It's also used as a communication system among the species.
Australian Museum's Jan Poulsen, lead author of the study, explained the importance of learning more about this peculiar kind of fish.
"This new study on the deep sea has shown unknown biodiversity in a group of fishes previously considered teratological [abnormal] variations of other species," Poulsen shared in a statement in EurekAlert.
"The different species of mirrorbelly-tube eyes can only be distinguished on pigmentation patterns that also constitute a newly discovered communication system in deep-sea fishes."