The Rough Triggerfish, Canthidermis maculata, whose common Spanish name is cochito manchado, is a species in the family Balistidae, the Triggerfishes, known as cochitos in Mexico. This fish is also known at the Spotted Oceanic Triggerfish. There are only three global members of the Canthidermis Genus, of which three are found in Mexican waters, one in the Atlantic, one in the Pacific and one in both oceans.
The Rough Triggerfish have elongated robust, compressed, and oblong bodies with a depth that is 44 – 48% of standard length. They are black to grayish dark blue and are covered with small white spots. Their head has a rounded profile, 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 are long and curved and their anterior rays are very elevated and much longer than their posterior rays; their caudal fin is doubly concave; their dorsal fin has three spines, the first of which can be locked erect and the second being one-half the size of the first; and their pelvic fins are minute. They have thick leathery skin.
The Rough Triggerfish are an ocean pelagic species that is normally found far out at sea. They are normally only observed around floating debris such as logs but have been found at depths up to 360 feet. They reach a maximum length of 50 cm (20 inches) and weigh up to 2.4 kg (5.2 pounds). They are found in all Mexican waters of the Atlantic. In the Pacific they are found from Acapulco south along the coast of the mainland to Guatemala and around all the oceanic islands. I have caught a fish that was about 10 miles north of La Playita and 30 miles into the Sea of Cortez, and have juveniles collected off the southwest coast of Baja extending the known northerly range for this species. They are a rare, deep water species and little is known about their behavioral patterns.
The Rough Triggerfish is an easy fish to identify and cannot be confused with any other species.
The Rough Triggerfish are exceedingly rare and therefore of limited interest.