Specklefin Cusk-eel, Lepophidium negropinna
The Specklefin Cusk-eel, Lepophidium negropinna, whose common Spanish name is congriperla pinta, is a species in the Cusk Eel or Ophidiidae Family, known collectively as brotula and congriperlass in Mexico. Globally, there are twenty-three species in the genus Leopophidium, 14 of which are found in Mexican waters, nine in the Atlantic and five in the Pacific.
The Specklefin Cusk-eels have elongated compressed bodies that taper to a point at the rear. They are a uniform dark brown color that is lighter ventrally. The key to identification is their dorsal fin margin which is black with a light inner portion featuring many dark spots and streaks. Their anal and caudal fins are black; their pelvic fins are pale; and their pectoral fins are slightly darker than the body. Their head is long and low with a round cross-section. Their mouth is large and broad and their eyes are large. Their anal and dorsal fin bases are long and continuous with their pointed caudal fin; the dorsal fin is longer that and originates before the anal fin. Their pectoral fins are long and reach more than half-way to the anal fin. Their pelvic fins have a pair of small threads inserted under the eyes. They have a strong snout spine that reaches beyond the tip of their upper jaw. They are covered with small round scales.
The Specklefin Cusk-eels inhabit sandy and muddy bottoms and are found demersal at depths between 60 and 1,280 feet. They reach a maximum length of 52 cm (20 inches). They hide in caves during the daytime and only emerge at night to feed on crustaceans, polychaete worms, small clams, and other invertebrates. They are poorly studied and very little is known about their behavioral patterns.
In Mexican waters the Specklefin Cusk-eels have a limited distribution being found from Guerrero Negro southward along the central and southwest coasts of Baja and throughout the Sea of Cortez.
The Specklefin Cusk-eel are easy to identify due to their uniquely colored dorsal fin and cannot be confused with any other species. They are obtained as a by-catch of deep water trawlers and by hook and line by commercial fishermen in the greater Los Cabos area, but are too rare and too small to be of commercial interest. They are seldom seen by humans and are of limited interest to most.
Specklefin Cusk-eel, Lepophidium negropinna. Fish provided by the commercial fishermen in the greater Los Cabos area, Baja California Sur, June 2009. Length: 42 cm (17 inches). Identification reconfirmed by Dr. Robert N. Lea, Monterey, CA.
Specklefin Cusk-eel, Lepophidium negropinna. Fish provided by the commercial fishermen in the greater Los Cabos area, Baja California Sur, Mexico, June 2011. Length: 49 cm (19 inches). Note the significant change in body shape as the fish matures.