Spotfin Cusk-eel, Ophidion galeoides

Spotfin Cusk-eel, Ophidion galeoides. Fish provided by the commercial fishermen of Bahía Kino, Sonora, November 2014. Length: 20 cm (7.9 inches). Photograph courtesy of Maria Johnson, Prescott College Kino Bay Center, Kino Bay, Sonora.

The Spotfin Cusk-eel, Ophidion galeoides, is a member of the Cusk Eel or Ophidiidae Family, and is known in Mexico as congriperla adornada. Globally, there are twenty-seven species in the genus Ophidion, of which seven are found in Mexican waters, two in the Atlantic and five in the Pacific Ocean.

The Spotfin Cusk-eel has a robust elongated compressed body that tapers towards the rear. They have a silvery brown coloration that is lighter ventrally. They have a dark spot just above their pectoral fin base after which they are named. Their flanks have a broken brown stripe along the lateral line with two or three spots below. Their anal fin has a broad black margin; their dorsal fin has a dark blotch at the front and a dark margin; and their pectoral fins have black tips. Their head has gill covers with a strong skin-covered spine at the upper corner. Their anal and dorsal fin bases are long and continuous with a rounded caudal fin; their pectoral and pelvic fins are of equal length; and, their pelvic fins each having two thread-like rays inserted under the eyes. Their body is covered with small, smooth, and elongated scales except the head is devoid of scales.

The Spotfin Cusk-eel is a demersal species that is found within and over sandy and muddy bottoms at depths up to 73 m (240 feet). They reach a maximum of 22.0 cm (8.6 inches) in length. They are rarely seen by humans because they hide in caves during the daytime and only emerge at night to feed on crustaceans, small clams, polychaete worms, and other invertebrates. The Spotfin-Cusk-eel is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Spotfin Cusk-eel is a resident of all Mexican waters of the Pacific Ocean with the exception that they are absent from Magdalena Bay, Baja California Sur, northward along the central and northwest coasts Baja, however, there is a known isolated population residing in the Guerrero Negro, Baja California, area.

The Spotfin Cusk-eel is very similar to a series of other Cusk-eels and specifically the Leopard Cusk-eel, Lepophidium pardale, the Mimic Cusk-eel, Ophidion imitator, the Panamic Cusk-eel, Otophidium indefatigabile, and the Spotted Cusk-eel, Chilara taylori, however they all have bodies covered with various sizes and shapes of black spots and lines.

From a conservation perspective the Spotfin Cusk-eel is currently considered to be of Least Concern with stable, widely distributed populations. They are caught primarily as a by-catch of deep water trawlers, 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.