Miles below the surface, a small pink fish with bumpy skin turned out to be something science had never seen before.
In 2019, a remotely operated vehicle was gliding above the seafloor of Monterey Canyon — more than 3,000 meters down, well beyond the reach of any natural light — when something small and pink drifted into frame. The fish was barely the length of a finger. Rounded head, wide fins, distinctly bumpy skin. Nothing the researchers aboard the Western Flyer had seen before in these waters.
The team noted it. Collected it. And quietly suspected it didn’t quite fit.
A chance encounter in the abyss
The ROV Doc Ricketts collected the small adult female — just 9.2 centimeters long — for laboratory study. Her features didn’t match anything MBARI researchers had documented in California waters, which prompted MBARI Senior Scientist Steven Haddock, who led the expedition, to reach out to taxonomy specialists for a closer look.
That outreach reflects something central to how MBARI operates. The institute regularly shares footage and specimens with expert taxonomists worldwide, giving outside researchers access to environments they couldn’t otherwise reach — a model built on openness that, here, paid off.
A review of MBARI’s video archive added another layer entirely. Footage from 2009, recorded off the Oregon coast, may show the same species — misidentified at the time as the bigtail snailfish. The bumpy snailfish could have been hiding in plain sight for more than a decade.
What makes a snailfish a snailfish
Snailfishes belong to the family Liparidae. They share a recognizable body plan: large head, jelly-like flesh, loose skin, and a narrow tapering tail. Many species also carry a suction disk on their belly, used to grip the seafloor or hitch rides on deep-sea crabs. Shallow-water relatives cling to rocks and kelp in much the same way.
More than 400 snailfish species have been described so far, occupying a remarkable range of habitats — from coastal tide pools all the way down to the deepest ocean trenches on the planet. One snailfish currently holds the record for the deepest fish ever observed.
SUNY Geneseo Associate Professor Mackenzie Gerringer has spent years studying how these animals survive conditions lethal to most vertebrates. Her work spans taxonomy, functional morphology, and physiology — all aimed at understanding life under crushing pressure, near-freezing temperatures, and total darkness. “The deep sea is home to an incredible diversity of organisms and a truly beautiful array of adaptations,” Gerringer said. “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.”
Three new species confirmed
The bumpy snailfish — now formally named Careproctus colliculi — is the most visually distinctive of the three. Pink coloration, a rounded head with large eyes, wide pectoral fins with elongated upper rays, and that bumpy skin texture that gave it its common name.
The second species, the dark snailfish (Careproctus yanceyi), is almost the visual opposite: entirely black, with a rounded head and a horizontal mouth. Both it and the sleek snailfish were collected in 2019 during a separate expedition using the submersible Alvin at Station M — MBARI’s long-term research site off Central California, at roughly 4,000 meters depth.
The third, the sleek snailfish (Paraliparis em), is long, black, and laterally compressed. It lacks a suction disk and has a prominently angled jaw. Its species name directly honors Station M and the researchers and programs that have sustained that time-series site over decades. All three were confirmed as new to science through microscopy, micro-CT scanning, careful physical measurements, and DNA sequencing.
The science behind the identification
To distinguish the three fish from all known species, the team built a detailed anatomical picture of each animal. Micro-CT scanning captured internal structures in three dimensions — data subsequently made publicly available through MorphoSource, so other researchers can access and compare it freely.
Genetic sequences were deposited in GenBank under accession numbers PV300955–PV300957 and PV298545–PV298546. Future researchers who collect an unfamiliar snailfish can check their specimen against these records directly. The collaboration extended across four institutions: Gerringer’s team at SUNY Geneseo led the taxonomic work, with contributions from researchers at the University of Montana, the University of Hawaiʻi at Mānoa, and former MBARI postdoctoral fellow Jeff Drazen. The findings were published in Ichthyology and Herpetology.
Why cataloging the deep sea matters now
The deep sea is Earth’s largest living space, holding enormous biodiversity — much of it still unnamed. Scientists estimate that a significant portion of deep-sea species remain undescribed, and the pace of exploration has historically been slow relative to the sheer scale of the environment.
That gap is becoming harder to ignore. Climate change is altering ocean temperatures and chemistry at depth, while deep-sea mining proposals are advancing in several regions. Both threats could reshape ecosystems that science has barely begun to document.
MBARI has described more than 300 new species over 38 years, combining advanced robotics with open data-sharing partnerships. Each new species adds a data point to a baseline that researchers will need if they hope to measure future change accurately.
The bumpy snailfish is a small pink fish, barely the length of a finger, living in near-total darkness more than three kilometers down. Collected once, in 2019, it may not be encountered again for years. But it now has a name, a genetic record, and a place in the scientific literature — a small but permanent foothold in human knowledge of a world we’re only beginning to understand. What else is down there, still unnamed, still drifting just out of frame, is a question worth sitting with.
The complete study is available here: Mackenzie E. Gerringer, Sarah Suplicz, Jessica L. Palmeri, Lydia Fregosi, Brett H. Woodworth, Emily McMahon, Samantha Shepard, Logan M. Peoples, Jeffrey C. Drazen. Descriptions of Three Newly Discovered Abyssal Snailfishes (Liparidae) from the Eastern Pacific Ocean. Ichthyology, 2025; 113 (3): 487 DOI: 10.1643/i2024069
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