Blacktail Snailfish, Careproctus melanurus
The Blacktail Snailfish, Careproctus melanurus, whose common Spanish name is baboso colinegra, is a member of the Snailfish or Liparidae Family, known collectively as peces babosos in Mexico. The snailfish comprise a large and diverse family with 334 members placed in 29 genera. Globally, there are 125 species in the genus Careproctus.
The Blacktail Snailfish have soft, flabby, scaleless bodies with a tadpole-like head and anal and dorsal fins that are continuous with the caudal fin which tapers to a point at the rear. They have a fairly unique body shape with modified pelvic fins that form a small sucking disc placed far forward below the eyes. Their anus is also very far forward and almost directly under the eyes (pictured below). They are overall light pink in color with black anal and dorsal fins. Their caudal fin is long and has a black tip. The lining of their mouth, their gill cavity, and their tongue are black. Their anal fin has 37 to 50 rays; their caudal fin is slightly rounded; and their dorsal fin has 54 to 58 rays. The first six rays of their pectoral fins are thick and standalone, whereas the next five rays are longer and less standalone. They have no lateral line.
The Blacktail Snailfish are a bathydemersal species found in muddy bottoms at depths between 270 and 7,000 feet. They reach a maximum length of 54 cm (21 inches) and can weigh up to 1.7 kg (4.3 pounds). They are bottom feeders and consume small clams, crustaceans, polychaete worms, and other invertebrates. They have a lifespan of up to eight years. They are a poorly studied species and very little is known about their behavioral patterns.
In Mexican waters the Blacktail Snailfish have a limited range being found only from Ensenada northward along the northwest coast of Baja.
The Blacktail Snailfish is straightforward to identify due to its characteristic shape and cannot be confused with any other species.
The Blacktail Snailfish are an abundant very deep water species but are seldom seen by humans. They are of limited interest to most and have not yet been evaluated from a conservation perspective.
Blacktail Snailfish, Careproctus melanurus. Fish caught off Point Loma, California, April 2008. Length: 24 cm (9.4 inches). Catch made by Eddie Kisfaludy, Scripps Institution of Oceanography, La Jolla, CA. Identification courtesy of H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, CA.