Blunthead Triggerfish

Blunthead Triggerfish, Pseudobalistes naufragium

The Blunthead Triggerfish, Pseudobalistes naufragium, whose common Spanish name is cochito bota, is a species in the Triggerfish or Balistidae Family, known collectively as cochitos in Mexico. There are only three global members of the genus Pseudobalistes, one of which is found in Mexican waters, this fish from the Pacific.

The Blunthead Triggerfish have robust, compressed, oblong, deep bodies that are 49 to 53% of standard length. They are pale blue to brownish gray with several alternating light and dark wide bars on their sides; these bars fade quickly after collection. Most have a visible white gill opening. In mature adults, the head has a blunt profile with disproportionately small beady eyes, a small mouth that opens at the front, powerful jaws with eight heavy human-like teeth on the upper and lower jaws, and a deep groove in front of the eyes. Their anal and second dorsal fins are of similar size and location and are exceedingly long in younger fish; their caudal fin varies from fish to fish being doubly concave with pointed lobes to rounded with small 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 first dorsal spine than to the second dorsal fin; and the pelvic fins are minute. They have thick leathery skin.

The Blunthead Triggerfish are found in and around rocky coral reefs and close to boulders adjacent to sand at depths up to 330 feet of the water column. They reach a maximum length of 100 cm (39 inches) and weigh up to 9.0 kg (19.8 pounds). They are a very rare, poorly studied species and very little is known about their behavioral patterns.

In Mexican waters, the Blunthead Triggerfish has a limited distribution being found from Magdalena Bay southward along the southwest coast of the Baja, in the southern two thirds of the Sea of Cortez, and along the coast of the mainland south to Guatemala.

The Blunthead Triggerfish can be confused with the Rough Triggerfish, Canthidermis maculata (body depth 43-45% of standard length; long anal and dorsal fins) and the Finescale Triggerfish, Balistes polylepis (body depth 55-57% of standard length; shorter anal and dorsal fins).

The Blunthead Triggerfish is exceedingly rare and therefore of limited interest. Based on my extensive experiences with their smaller brothers, the Finescale Triggerfish, they might be the toughest foe in the sea pound for pound.

Blunthead Triggerfish, Pseudobalistes naufragium. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, August 2009. Length: 63 cm (25 inches).