Finescale Triggerfish, Balistes polylepis
The Finescale Triggerfish, Balistes polylepis, whose common Spanish name is cochi, is a species in the Triggerfish or Balistidae Family, known collectively as cochitos in Mexico. Globally, there are only seven members of the Balistes Genus, three of which are found in Mexican waters, two in the Atlantic and one in the Pacific.
The Finescale Triggerfish have robust, compressed, and oblong bodies with a depth that is 57 to 61% of standard length. They are a drab uniform brownish-tan color with hints of blue throughout. Mature adults have bright neon blue markings that “light up” on their head and the edges of their fins when feeding or fighting aggressively. Their head has a rounded profile and a flat beak, modest-sized eyes, a small mouth that opens at the front, and powerful jaws with eight heavy human-like teeth on the upper and lower jaws. Their anal fin and second dorsal fin rays are longer than their rear rays; their caudal fin is doubly concave with prolonged lobes; their dorsal fin has three spines, the first of which can be locked erect, the second being one-half the size of the first, and the third being closer to the second dorsal fin than the first dorsal spine; and their pelvic fins are minute. They are covered with thick leathery skin composed of small and fine scales.
The Finescale Triggerfish inhabit rocky reefs and slopes with borders adjacent to sand. They are found from the surface to depths of up to 1,700 feet. They reach a maximum length of 80 cm (31 inches) and weigh up to 3.2 kg (7.0 pounds). Although they have a vast range, little is known about their behavioral patterns.
In Mexican waters the Finescale Triggerfish are found in all waters of the Pacific.
The Finescale Triggerfish is an easy fish to identify and normally cannot be confused with any other species, however juveniles and young adults are very similar to the very rare Blunthead Triggerfish, Pseudobalistes naufragium (dark skinned covered with thin blue lines). They are also quite similar to the Gray Triggerfish, Balistes capriscus, found only in the Atlantic Ocean.
The Finescale Triggerfish are a strong foe on light tackle; they might even be the strongest fish in the ocean pound for pound. Beware of their truly lethal chomp which can take two weeks to recover from! They are caught off the bottom with tradition bottom rigs on cut bait utilizing ample chum, however stronger than normal small hooks are recommended as they will demolish traditional hooks. They are, however, very elusive and travel in large schools that are continually on the move. They can be caught off the beach at certain times of the year. Juveniles can be encountered on the surface far out at sea and collected with a bait net; presumably they approach the Panga seeking shelter. The Finescale Triggerfish are deemed an excellent food fish and are primarily used by locals for ceviche. They can be found on rare occasions in the markets of the greater Los Cabos area.
Finescale Triggerfish, Juvenile, Balistes polylepis. Fish collected off the ocean surface with a bait net north of Puerto Los Cabos, Baja California Sur, December 2007. Length: 5.0 cm (2.0 inches). Identification courtesy of H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, CA.
Finescale Triggerfish, Deformed, Balistes polylepis. Four fish caught in the greater Los Cabos area, Baja California Sur, all with unique deformities. Lengths: 30 cm (12 inches) to 38 cm (15 inches). It is a jungle down there!
Finescale Triggerfish, Balistes polylepis. Fish caught from coastal waters within Gonzaga Bay, Baja California, June 2015. Length: 40 cm (16 inches). Catch and photo courtesy of Chris Wheaton, Loreto, Baja California Sur.
Finescale Triggerfish, Balistes polylepis. Fish caught from coastal waters off Puerto Adolfo Lopez Mateos, Baja California Sur, July 2016. Length: 59 cm (23 inches) with Captain Jimmy Camacho by his brother Jesus, Puerto Adolfo Lopez Mateos, Baja California Sur.