Marine biologists have identified three new species of deep-sea catanus fish belonging to the Lipalidae family in the Eastern Abyssian area of the Pacific (depths of 3,268-4,119 m).

The family of these fish, known as Repalidae, thrives in temperate to cold waters across the ocean basin.

These species play a significant role in ecosystems ranging from the intertidal zones to the hadal trenches (over 6,000 m).

They are well adapted to various habitats, likely due to their rapid evolutionary rates.

In shallower waters, these fish utilize specialized ventral suction discs to cling to rocks, adopting a curled, snail-like posture which gives rise to their common English name.

“The family Ripalidae comprises 31 accepted genera and 450 recognized species, with 43 being described in the last decade,” stated Dr. Mackenzie Gellinger from the State University of New York.

“At the family level, these fish are distinguished by their skate-like body, ventral suction discs formed by modified pelvic fins in many genera, and their elongated body structure.”

“Given the ecological significance of this family, the rapid discovery of new snail fish, and the important efforts needed to revise catanus classification, studying snail taxonomy is essential for advancing our understanding of marine biodiversity.”

The three new species are the bumpy snail (Careproctus colliculi), the dark snail (Careproctus yanceyi), and the sophisticated snail (Paralyparis em).

Paralyparis em and Careproctus yanceyi were collected using a suction sampler from a depth of 4,100 m via the human occupied vehicle (HOV) Albin on the R/V Atlantis.

Careproctus colliculi was gathered by remotely operated vehicles (ROVs) Doc Ricketts on the R/V Western Flyer using a suction sampler from under 100 km off the coast of Monterey Bay, California.

To describe these new species, the authors utilized microscopy, micro-computed tomography (Micro-CT) scans, and meticulous measurements to gather specific data on size, shape, and various physical characteristics such as fin rays and vertebrae for each fish.

“Careproctus colliculi is identified by its pink body, 22 cerebral rock rays, rounded head, eight caudal rays, large eyes, and well-formed wing-like structure that creates a large suction disc,” they explained.

“Careproctus yanceyi features a medium-sized abdominal suction disc, a single nostril, and six branched rays, distinguishing it from other Eastern Pacific deep-sea snails, which have round heads and entirely black bodies with horizontal mouths.”

“Paralyparis em is marked by its long, black, laterally compressed body, absence of a suction disc, sharply angled jaw, a single chest radial, anteriorly positioned anal fin, and five branched rays.”

Researchers also sequenced the DNA of the fish and compared it with other snail species to contextualize the new species within their evolutionary framework.

“Taxonomic methods are crucial for comprehending the organisms we share our planet with and for studying and safeguarding global biodiversity,” Dr. Gellinger asserted.

“The deep sea is home to an astonishing variety of creatures with remarkable adaptations.”

“These three catanus fish serve as a reminder of how much remains unknown about life, the thrill of curiosity, and the power of exploration on Earth.”

The research findings are detailed in a new paper published in the journal Ichthyology and Herpetology.

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Mackenzie E. Gellinger et al. 2025. Description of three newly discovered Abyssal snails (Liparidae) from the Eastern Pacific Ocean. Ichthyology and Herpetology 113(3): 487-506; doi: 10.1643/i2024069