With large heads and a jelly-like body covered in loose skin, you’d think that something as unique-looking as the bumpy snailfish would be easy to spot. You’d be wrong, because until now, this wholly unfamiliar species of deep-sea snailfish wasn’t even known to science.

Major advances in underwater technology, however, have helped scientists across the globe reveal some of the deepest secrets of the deep sea – the bumpy snailfish (Careproctus colliculi) being just the latest among them.

Using technology developed by the Monterey Bay Aquarium Research Institute (MBARI), researchers from the State University of New York at Geneseo alongside those from the University of Montana and the University of Hawai’i at Mānoa, have been able to publish findings describing three new to science species of snailfish observed along the abyssal seafloor offshore of California.

Those findings have now been published in the scientific journal Ichthyology and Herpetology.

Snailfish belong to the family Liparidae and typically feature a large head, jelly-like bodies covered in loose skin, and a narrow tail. Many snailfish species have a disk on their belly that allows them to grip the seafloor or hitchhike on larger animals, such as deep-sea crabs. Shallow-water snailfishes often cling to rocks and seaweed, curling up like a snail.

More than 400 different species of snailfish have now been described across the globe, each of them making their homes in a variety of ocean habitats, from shallow tide pools to deep-sea trenches. In fact, a snailfish even holds the record for being the deepest-dwelling fish.

“The deep sea is home to an incredible diversity of organisms and a truly beautiful array of adaptations,” said SUNY Geneseo associate professor, Mackenzie Gerringer, a specialist in deep-sea physiology and ecology.

“Our discovery of not one, but three, new species of snailfishes is a reminder of how much we have yet to learn about life on Earth and of the power of curiosity and exploration.”

The newly described snailfish were observed at two sites. Two of the fishes were collected by the research submersible Alvin from a depth of 13,513 feet, at Station M – a long-term deep-sea research observatory around 130 miles off the coast of California.

The third fish was collected during an expedition aboard MBARI’s retired flagship research vessel, Western Flyer to the outer reaches of Monterey Canyon, approximately 100 kilometres offshore of Central California. It was MBARI’s remotely operated vehicle Doc Ricketts that explored the depths of some 3,268 metres when it observed the small snailfish swimming above the abyssal seafloor.

This individual – an adult female measuring 9.2 centimetres in length – was collected for further study. Using microscopy, micro-computed tomography scanning, and careful measurements, Gerringer and her team collected detailed information about the size, shape, and physical characteristics of the three fish, distinguishing them from all known species.

They also sequenced the DNA of the specimens to compare these animals to other snailfish and determine their evolutionary position in the family Liparidae. It was during this process the team confirmed that all three snailfish were new to science.

“Taxonomy is essential for understanding the organisms with whom we share our planet and for studying and conserving the global biodiversity,” said Gerringer.

Brett Woodworth, a co-author on the study – Descriptions of three newly discovered abyssal snailfishes from the eastern Pacific Ocean – has said the study emphasises the importance of both morphological and genetic identification for deep-living fish.

“The two species collected at Station M are cryptic – their external morphologies are similar to one another. Through both forms of identification, we were not only able to distinguish between the two species, but we could compare them to known species to gain a better understanding of snailfish evolution in the deep sea.”

The discovery of these new species adds to our growing understanding of deep-sea communities at abyssal depths, which make up 50% of the surface of the Earth.

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