Threadfin Bass

Threadfin Bass, Pronotogrammus multifasciatus

The Threadfin Bass, Pronotogrammus multifasciatus, whose common Spanish name is Serrano Baga, is a member of the Sea Bass or Serranidae Family, known collectively as “serranos” in Mexico. It received its common name from length of the long pelvic fins which are significantly longer those found in most fish. The Threadfin Bass is an Anthias, a subfamily of Serranidae, that make up the majority of pink, orange, red and yellow reef fishes seen swarming in most coral reef photography and film.

The Threadfin Bass is one of the few bright red fishes and is found only in very deep waters. They have elongated bodies with short heads. The eyes are moderate in size, the mouth is oblique and the lower jaw is projecting. They are characterized by a uniform overall red-pink coloration, very long pelvic fins, short pectoral fins that do not reach the anal fin origin, a forked caudal fin, approximately twenty thin irregular yellow bars along the sides, and a yellow stripe under its eyes. All of the fins are red and tipped in yellow.

The Threadfin Bass aggregate over rocky structure at depths between 240 and 1,000 feet. They reach a maximum length of 29 cm (11.4 inches), documented by a fish that we have caught, and weight less than 450 grams (1 pound). They are a small, rare, deep-water species and not much is known about behavioral patterns.

The Threadfin Bass is a very easy identification and cannot be confused with any other species. They are found in all Mexican waters of the Pacific.

The Threadfin Bass is a common catch in the greater Los Cabos area. However, when released, they will not return to the deep and are almost immediately consumed by the Magnificent Frigate Bird, Fregata manificus, who post consumption will always return to ocean twice for drinks of water which provides splendid entertainment.

Threadfin Bass, Pronotogrammus multifasciatus: Fish caught out of 200-foot water off Point Palmilla, Baja California Sur, November 2006, utilizing a Sabiki rig. Size: 20 cm (8.0 inches). Fish identification courtesy of Dr. Ross Robertson, Smithsonian Tropical Research Institute, Panama.

Threadfin Bass, Pronotogrammus multifasciatus: Fish caught out of 200-foot water off Point Palmilla, Baja California Sur, November 2006, utilizing a Sabiki rig. Size: 20 cm (8.0 inches). Fish identification courtesy of Dr. Ross Robertson, Smithsonian Tropical Research Institute, Panama.