Advanced underwater technology reveals a new species of deep-sea snailfish

MBARI’s advanced underwater technology is revealing the remarkable species that thrive in the deep sea. In 2019, MBARI researchers encountered an unfamiliar pink snailfish swimming just above the seafloor. New research from MBARI collaborators has confirmed this individual represents a species previously unknown to science: the bumpy snailfish (Careproctus colliculi).

A team of researchers from the State University of New York at Geneseo (SUNY Geneseo), with scientists from the University of Montana and the University of Hawaiʻi at Mānoa, published their findings in the journal Ichthyology and Herpetology, describing the bumpy snailfish observed by MBARI researchers alongside two other snailfishes from the abyssal seafloor offshore of California.

“MBARI seeks to make ocean exploration more accessible by sharing our data and technology with our peers in the science community. We welcomed the opportunity to collaborate with researchers from SUNY Geneseo to expand our understanding of life in the deep ocean, especially since documenting deep-sea biodiversity is critical to detecting any changes that may be occurring in this environment,” said MBARI Senior Scientist Steven Haddock, who led the research expedition that encountered the bumpy snailfish.

Uncovering secrets to survival in extreme environments

Snailfishes belong to the family Liparidae. They typically have a large head, jelly-like body covered in loose skin, and 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.

Scientists have described more than 400 different species of snailfish worldwide. These fishes make their homes in a variety of ocean habitats, from shallow tide pools to deep-sea trenches. In fact, a snailfish holds the record for the deepest-dwelling fish.

SUNY Geneseo Associate Professor Mackenzie Gerringer studies deep-sea physiology and ecology and has conducted extensive research on deep-sea snailfishes. Her research uses comparative techniques in taxonomy, functional morphology, and physiology to understand how fishes are adapted to life under crushing pressure, frigid cold, and perpetual darkness in the ocean’s depths.

“The deep sea is home to an incredible diversity of organisms and a truly beautiful array of adaptations. 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,” said Gerringer.

Chance encounters spark new discoveries

MBARI’s Biodiversity and Biooptics Team observed the newly described bumpy snailfish during an expedition aboard the institute’s retired flagship research vessel Western Flyer. Haddock and his team were exploring the outer reaches of Monterey Canyon, approximately 100 kilometers (62 miles) offshore of Central California, with MBARI’s remotely operated vehicle Doc Ricketts at a depth of 3,268 meters (10,722 feet) when they observed this small snailfish swimming above the abyssal seafloor.

MBARI researchers collected this individual—an adult female 9.2 centimeters (3.6 inches) long—for further study in the laboratory. With features unlike other deep-sea snailfishes that MBARI had encountered offshore of California, Haddock reached out to Gerringer for more detailed analysis. MBARI frequently collaborates with expert taxonomists to review footage and specimens. These partnerships offer fresh perspectives that often spark new discoveries.

New additions to the family

Gerringer and researchers from the University of Montana and the University of Hawaiʻi at Mānoa, including former MBARI postdoctoral fellow Jeff Drazen, examined the bumpy snailfish as part of a comprehensive analysis of three unusual snailfish specimens collected offshore of California. The team combined imaging, morphological, and genetic approaches to compare these snailfishes to other known fishes.

Using microscopy, micro-computed tomography (micro-CT) scanning, and careful measurements, the team collected detailed information about the size, shape, and physical characteristics of the three fishes, distinguishing them from all known species. They also sequenced the DNA of the specimens to compare these animals to other snailfishes and determine their evolutionary position in the family Liparidae. Their examination confirmed that all three snailfishes were new to science.

The team has made their CT scan data publicly available via MorphoSource and genetic sequence data via GenBank (PV300955-PV300957 and PV298545-PV298546).

In addition to the bumpy snailfish, the SUNY Geneseo team described the dark snailfish (Careproctus yanceyi) and the sleek snailfish (Paraliparis em).

The bumpy snailfish has a distinctive pink color, a round head with large eyes, wide pectoral fins with long uppermost rays, and a bumpy texture. The dark snailfish has a fully black body with a rounded head and horizontal mouth. The sleek snailfish is distinguished from other snailfishes by a long, black, laterally compressed body, absence of a suction disk, and prominently angled jaw.

Both the dark and sleek snailfishes were collected in 2019 by Drazen and colleagues during an expedition with the submersible Alvin at Station M, a research site operated by MBARI offshore of Central California at a depth of approximately 4,000 meters (13,100 feet).

MBARI scientists and researchers worldwide have leveraged a unique 30-year dataset collected by a suite of advanced instruments at Station M to make several important discoveries about abyssal ecosystems and the ocean-climate connection. The species name of the sleek snailfish, Paraliparis em, recognizes this unique research site and the people and programs that have supported the Station M time series.

Haddock’s encounter is the only confirmed observation of the bumpy snailfish, so the full geographic distribution and depth range of this species remain unknown. However, a closer look at MBARI’s extensive archive of underwater video suggests this species may have been previously encountered offshore of Oregon in 2009 and mistaken for a similar species, the bigtail snailfish (Osteodiscus cascadiae).