#liparidae

ESP version ITA version

Instagram Facebook Linktree

We still know very little about the living beings that inhabit the ocean waters surrounding our planet. It is estimated that more than 80% of the oceans has not yet been mapped or explored; therefore, every new discovery adds a building block to our limited ocean knowledge. In this context, thanks to a 2019 expedition, it was possible to identify three new species of snailfish.

Snailfish, family Liparidae (Cottoidei), live in temperate to cold habitats across all ocean basins, playing very important roles in ecosystems. Their common name comes from the fact that most of them have a specialized ventral suction disc used to cling to rocks; when this happens, the animal adopts a curled posture, much like land snails. These animals are found both in shallow waters and in trenches exceeding 8,000 m in depth—areas that are difficult to explore.

The specimens collected in 2019 live at depths between 3,268 and 4,119 m in the eastern Pacific, and their identification was made possible through tissue collection, DNA amplification and sequencing, microscopy, and micro–computed tomography. Phylogenetic—evolutionary—analyses made it possible to compare their genetic data with those of other species and to confirm that they are three new species.

The first is Careproctus colliculi: pink in life, it has 22 pectoral-fin rays, a rounded head, 8 caudal rays, large eyes, and well-developed pterygiophores—bones or cartilages that articulate the base of the median fin rays—forming a large suction disc. Its scientific name refers to the small characteristic bumps (from Greek) that cover the skin, especially the head and the front of the fish.

The second species, C. yanceyi, has a moderate ventral suction disc (<3% of standard length), single nostrils, and 6 branchiostegal rays. It has an entirely black body, rounded head, and horizontal mouth. The species is dedicated to Dr. Paul Yancey, of Whitman College, USA, for his contribution to deep-sea biology.

The third species is Paraliparis em, with a long, black, laterally compressed body. It lacks a suction disc, has a single pectoral-fin ray, an anteriorly positioned anus, and a strongly angled jaw. The species is named after the collection site, Station M, paying tribute to all the researchers who have worked there.

These discoveries help to fill gaps in abyssal sampling and remind us of the importance of integrating observations, morphology, and genetics to understand marine biodiversity.

See You Soon and Good Science!

Source

A recently discovered deep sea fish from the Atacama Trench, a large trench near the coast of Chile and Peru, in the west coast of South America, sheds light on how fish species colonize deep sea environments. 

Reaching the size of a hand, this deep sea fish is named Paraliparis selti, and is related to southern ocean species rather to typical deep sea snail fishes, according to molecular and micro computed tomography analysis. The genus Paraliparis is abundant in the Southern Ocean, as well in the Antarctic, but surprising, this fish is the first member of the genus found in the hadal zone, at 6500 m depth.

This trench is poorly explored, in 2018, three snailfishes, similar looking to Paraliparis selti, were discovered.

Photo: In situ still images of P. selti sp. nov. taken by baited camera at  6520 to 6714 m depth. Scale bars 50 mm

Reference: Linley et al. 2022. Independent radiation of snailfishes into the hadal zone confirmed by Paraliparis selti sp. nov. (Perciformes: Liparidae) from the Atacama Trench, SE Pacific. Mar. Biodivers.

Swimming with the Mariana Snailfishes

The Mariana Snailfish (Pseudoliparis swirei) Is one of the deepest-living fishes in the world. It is native to the Mariana Trench in the Pacific Ocean, and is found at depths of 6,000 to 8,000 meters. At that point, the pressure is almost 600 atm, or the equivalent of 1,600 elephants per square inch. Beyond this point, certain proteins begin to break down and bones can be crushed. However, the Mariana Snailfish has several adaptations that allow it to survive, and even thrive, at such pressures.

For starters, P. swirei’s skeleton is not completely ossified. This means that their bones are not fully calcified, but consist mainly of cartilage, which gives snailfishes some flexibility. There are also gaps in its skull to stabilize the pressure. Furthermore, to prevent proteins in its body from breaking down, the Mariana Snailfish has a special chemical called trimethylamine N-oxide which stabilizes proteins. Most animals have one gene to produce this compound; Mariana Snailfishes have five genes. Because of this, they can also produce larger amounts of proteins to counteract the effect of pressure on the ability to move chemicals from one cell to another. Finally, like many other deep-sea organisms, these fishes lack functioning eyes and almost completely lack pigment.

Although it’s small, at anywhere from 6 inches to just under a foot, the Mariana Snailfish is also the top predator of the Mariana Trench. They feed primarily on crustaceans and arthropods along the ocean floor, although they are also known to consume carrion or small fish when given the opportunity. Their eggs are similarly proportioned, with diameters of up to a third of an inch, in large clutches of almost 900. Out of all of these, only a handful are typically mature, and it is unknown if Mariana Snailfish provide parental care or what juvenile growth is like. In fact, very little else is known about the Mariana Snailfish, due to its size and the extreme inaccessibility to its habitat.

MARIANA SNAILFISH: THIS PALE PINK AND CUTE IS DEEPEST FISH KNOWN TO SCIENCE

After recorded them in video in 2014, researchers have described the world's deepest fish. Named Mariana snailfish (Pseudoliparis swirei), the new species lives in the ocean region known as the hadal zone, one of the deepest area in the ocean. Believe to be endemic of this area, between 2014 and 2017, researchers collected 37 individuals in the Mariana Trench, from 6,900 m to 7966 m depth, now the results are published in the journal Zootaxa.

Prior to its formal scientific description, a Japanese expedition recorded also a snailfish of the Marianas at depths of 8,178 meters ( gif above, probably the same species), the deepest sighting so far and quite possibly the greatest depth a living creature can bear, biologically speaking. To resist the pressures at deep ocean environments, fish produce a substance called osmolyte, which helps cells maintain volume and fluid balance. Nevertheless, fish can not produce any of this substance below 8,200 meters, which is why scientists say that, at least theoretically, it is hard to find fish below this threshold. Curiously, snailfish live above this limiting edge.

GIF: JAMSTEC Channel