Scientists describe a new deep‑sea snailfish found more than 3,200 metres underwater

Scientists have described a previously unknown species of deep‑sea snailfish recovered from the seafloor off central California, naming the animal the bumpy snailfish (Careproctus colliculi).

The specimen was collected in 2019 by researchers from the Monterey Bay Aquarium Research Institute (MBARI) using a remotely operated vehicle during an expedition to the outer reaches of Monterey Canyon, about 100 kilometres offshore. The individual, an adult female 9.2 centimetres long, was recorded and retrieved from a depth of 3,268 metres (approximately 10,722 feet).

Detailed examination using microscopes, micro‑CT scanning and morphometric measurements showed the animal had a combination of features not seen in any previously described snailfish species. The bumpy snailfish is reported as having a pink hue, a round head with relatively large eyes, wide pectoral fins with elongated upper rays and a textured, bumpy skin surface.

Researchers said the bumpy snailfish was one of three new snailfish taxa identified as part of the same research programme. Two additional specimens analysed by the team were described as the dark snailfish, characterised by a fully black body, rounded head and a horizontal mouth, and the sleek snailfish, noted for a long, black laterally compressed body, lack of a ventral suction disk and an angled jaw. MBARI scientists also reported video observations of a snailfish that may correspond to a slender snailfish, but they did not collect a specimen for formal identification.

Steven Haddock, a senior scientist at MBARI who led the expedition that first encountered the bumpy snailfish, said documenting deep‑sea biodiversity is important for tracking changes in marine ecosystems. "The deep sea is home to an incredible diversity of organisms and a truly beautiful array of adaptations," Mackenzie Gerringer, an associate professor at the State University of New York at Geneseo who commented on the discovery, said in a statement released by the researchers.

The study describing the new species was published in the journal Ichthyology and Herpetology. The authors noted that many deep‑sea snailfishes are difficult to identify from video alone, which makes specimen collection and high‑resolution imaging critical for taxonomic work in the deep ocean. The bumpy snailfish encounter is currently the only confirmed observation of that species, and the team said additional work is required to determine its full geographic distribution and depth range.

Snailfishes belong to the family Liparidae, a group that includes more than 400 described species that occupy a wide range of ocean habitats from shallow tide pools to some of the deepest parts of the global ocean. Members of the family commonly have a large head, a gelatinous body and, in many species, a suction disk on the belly that they use to adhere to hard surfaces or to other animals. Liparids hold the record for the deepest‑dwelling fishes known to science.

MBARI made the discovery while exploring benthic habitats using a robotic submersible. The organisation has published video and images from numerous deep‑sea expeditions over the last decade, and scientists at the institute continue to catalogue organisms collected during those cruises. The researchers emphasised that each new species description extends understanding of life in the deep sea and provides baseline data useful for future ecological and conservation assessments.

Public reaction to images and video of the bumpy snailfish on social platforms has ranged from amusement to admiration, with some viewers likening its appearance to fictional creatures. The scientific description, however, focuses on anatomical distinctions and comparisons with related taxa, leaving questions about behaviour, population size and broader habitat preferences for future study.