Ocean Triggerfish, Canthidermis sufflamen
The Ocean Triggerfish, Canthidermis sufflamen, whose common Spanish name is sobaco lija, is a species in the Triggerfish or Balistidae Family, known collectively as cochitos in Mexico. Globally, there are only three species in the genus Canthidermis, all three being found in Mexican waters, one in the Atlantic, one in the Pacific, and one in both the Atlantic and the Pacific.
The Ocean Triggerfish have robust, compressed, and oblong bodies that elongate with maturity; juveniles have a depth that is 56% to 60% of standard length whereas this percentage can drop to as low as 44% in adults. They are drab gray to brownish-gray with a large dark blotch at the base of their pectoral fin (a key to the identification). Their head has a pointed profile, a blunt snout, modest-sized eyes, and a small mouth that opens at the front. They have powerful jaws with eight heavy outer teeth that are uneven in size on their upper and lower jaws. Their anal fin has 23 to 25 rays. Their caudal fin is doubly concave but rounded in juveniles. Their dorsal fin has 3 spines and 26 or 27 rays; the first spine can be locked erect and the second spine is half the size of the first. Their pectoral fin has 15 or 16 rays and their pelvic fins are minute. Their anal fin and soft dorsal fin have long bases and are curved with well-developed anterior rays. Their lateral line is inconspicuous. They are covered with thick leathery skin and are fully scaled.
The Ocean Triggerfish are a pelagic species found in and around floating objects including Sargassum beds at depths between 20 and 240 feet. They reach a maximum length of 65 cm (26 inches) and 6.1 kg (13.4 pounds) in weight. They are solitary or found in small groups that can number up to 50 individuals. They feed primarily on zooplankton but are important to the marine environment keeping sea urchin populations in check. Reproduction is oviparous and occurs in mass spawning aggregations in harems of one male and up to six females. Males prepare up to a dozen nests in hollows and then patrol the area, driving unwanted fish away. Females release eggs in the nests throughout the year and these eggs are then fertilized by males. The eggs are protected by both parents and the hatched larvae become pelagic. They are an uncommon species and little is known about their behavioral patterns.
In Mexican waters the Ocean Triggerfish are found in all waters of the Atlantic.
The Ocean Triggerfish is an easy fish to identify and cannot be confused with any other species with the possible exception of the Gray Triggerfish, Balistes capriscus (more colorful; anal and caudal fins with barring; straight anal and dorsal fin margins).
The Ocean Triggerfish are not a targeted species and normally an incidental catch taken by hook and line. They are sold on a limited basis in some local fish markets within their range. From a conservation perspective they are considered of Least Concern being widely distributed, common, and abundant within their range. Being curious and intelligent fish, they are used on a limited basis by the aquarium trade but are aggressive and require a large aquarium with continual extensive maintenance.
Ocean Triggerfish, Canthidermis sufflamen. Fish caught off the surface at Pulley Ridge, August 2014. Length: 12.5 cm (5.0 inches). Catch, photo, and identification courtesy of George Brinkman, Guelph, Ontario, Canada. Note: there is a very remote possibility that this is a Gray Triggerfish, Balistes capriscus; identification of juveniles is difficult and access to quality photos of juveniles is limited.
Ocean Triggerfish, Canthidermis sufflamen. Fish caught from coastal waters off Key West, Florida, March 2017. Length: 46 cm (18 inches). Catch and photo courtesy of Dean Kimberly, Atlanta, GA.