New glow in the dark discovery: Deep-sea nudibranch amazes scientists
Scientists from the Monterey Bay Aquarium Research Institute (MBARI) have discovered a new species of nudibranch. They encountered it in the depths of the Pacific Ocean, where no nudibranchs had been found before. However, that was not the most surprising aspect.
2:34 PM EST, November 13, 2024
Most nudibranchs, colorful and decorative sea slugs, live in shallow waters, often among coral reefs. However, Bathydevius caudactylus surprised scientists with its habitat. Specimens of this species were found in open water at a depth of over 7,200 feet, where complete darkness prevails.
Most nudibranchs live on the bottom in shallow water, so it was very surprising to find a nudibranch so deep in the water column and far from the bottom, said Bruce Robison, a marine scientist at MBARI — said Bruce Robison, a marine scientist at MBARI, in an interview with "ScienceAlert".
Scientists observed a total of 157 specimens of this species during dives conducted from 2000 to 2021. Among them, 32 were thoroughly examined, and 18 were collected for further laboratory analysis. Genetic studies allowed the classification of Bathydevius caudactylus as a nudibranch, but it was so distinct that a new family had to be created—Bathydeviidae.
An extraordinary nudibranch species discovered
Bathydevius caudactylus stands out not only for its habitat but also for its unique features. It has a broad, unrolled hood with which it captures its prey, mainly crustaceans. Through the ethereal, transparent skin on its body, you can see pink internal organs.
Moreover, this species displays bioluminescence. Scientists observed that when threatened, Bathydevius caudactylus emitted a luminous glow and even discarded glowing tail protrusions to confuse predators. Studies also showed that Bathydevius caudactylus is hermaphroditic.
The most exciting aspect of this discovery is that we were able to make the most comprehensive initial description of a new deep-sea species ever presented (anatomy, respiration, bioluminescence, reproduction, feeding, genetics, behavior) — said Robison to ScienceAlert.
The results of these extensive studies, published in the journal "Deep-Sea Research Part I," indicate that the evolution of nudibranchs is much more flexible than previously thought. Bathydevius is radically different from all other nudibranchs because it is perfectly adapted to life in a completely different environment — summarized Robison.
