Rainbow Basslet

Rainbow Basslet, Liopropoma fasciatum

The Rainbow Basslet, Liopropoma fasciatum, whose common Spanish name is Cabrilla Arcoiris, is a member of the Sea Bass or Serranidae Family, known collectively as “Serranos” in Mexico. They are a very colorful fish and one of the few bright oceanic fishes; as a result, they are sold extensively by the aquarium trade.

The Rainbow Basslets have elongated bodies and pointed heads. They have a near horizontal profile with large eyes and a slightly upturned and very large mouth with a projecting lower jaw. Their head and belly are red and there are four horizontal stripes on their sides: a wide dark brown mid-lateral stripe, straddled by a strong yellow stripe above and a faint yellow stripe below, and a red-brown stripe just below the base of their dorsal fin (pictured below). Their dorsal fin has seven rays and a yellow stripe near the base. They have a very deep tail base, which is greater than half the depth of the body, and their tail is concave. They are covered with small rough scales.

The Rainbow Basslets are found in and around rocky and coral reefs at depths between 75 and 750 feet. They reach a maximum length of 33 cm (13 inches) and weigh less than 450 grams (1 pound). They have a limited distribution in Mexican waters of the Pacific being found in the lower two-thirds of the Sea of Cortez and along the coast of the mainland south to Guatemala. They are a rare deep water species, which lacks significant scientific behavioral information.

The Rainbow Basslet is straightforward to identify due to its unique coloration pattern. In body shape it is similar to the Scalyfin Basslet, Liopropoma longilepis, however, the latter lacks the mid-body banding.

The Rainbow Basslet is a rare catch by hook and line and is too small to be of interest to most.

Rainbow Basslet, Liopropoma fasciatum: Fish caught out of 200-foot water at Gordo I, Baja California Sur, February 2007, on cut squid utilizing a traditional bottom rig. Size: 18 cm (7.1 inches). Identification courtesy of Dr. Ross Robertson, Smithsonian Tropical Research Institute, Panama.
Rainbow Basslet, Liopropoma fasciatum: Fish caught out of 200-foot water at Gordo I, Baja California Sur, February 2007, on cut squid utilizing a traditional bottom rig. Length: 18.0 cm (7.1 inches). Identification courtesy of Dr. Ross Robertson, Smithsonian Tropical Research Institute, Panama.