Medusafish, Icichthys lockingtoni

Medusafish, Icichthys lockingtoni. Fish collected in a deep-water trawl net off Point Loma, California, August 2010. Length: 19.0 cm (7.5 inches). Catch courtesy of H.J. Walker, Jr., Scripps Institute of Oceanography, La Jolla, California.

The Medusafish, Icichthys lockingtoni, is a member of the Medusafish or Centrolophidae Family, and is known in Mexico as cojinoba medusa. The Medusafish is named after Medusa, an ugly creature from Greek mythology with hair made of snakes. Globally, the Centrolophidae Family includes thirty-two species placed in seven genera with two global species in the genus Icichthys. Two members of the Centrolophidae family are found in Mexican waters, one in the Atlantic and this species from the Pacific Ocean.

The Medusafish has an elongated rectangular body. They are bluish-gray overall with dusky to black fins and are darker on their scale pockets. Their head is small with large eyes and their mouth ends under the middle of the eyes. They have a pronounced forehead and a large rounded snout. The anal fin has a long base with 3 spines and 20 to 25 rays; the caudal fin has a long base and is rounded with a small notch; the dorsal fin has a long base with 3 spines and 34 to 39 rays; and the pectoral fins are small and rounded.

The Medusafish is a rare species typically found in the temperate and tropical deep-waters of the Pacific from the surface to depths of 1,000 m (3,300 feet). Juveniles are pelagic and found in shallower waters than adults. They reach a maximum length of 46 cm (18 inches). Young are abundant offshore and associated with jellyfish, which protects them from predation and provides opportunities to scavenge leftover jellyfish meals. The Medusafish 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 Medusafish is is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found from Guerrero Negro, Baja California, northward along the central and northwest coasts of Baja.

From a conservation perspective the Medusafish has not been formally evaluated. They are a very rare species and are seldom seen by humans. Please consider yourself privileged if you ever see one of these fish!