Ocean Triggerfish

Ocean Triggerfish, Canthidermis sufflamen

Ocean Triggerfish, Canthidermis sufflamen. Fish caught off the surface at Pulley Ridge,  100 miles west of the Tortugas Ecological Reserve, Florida Keys, August 2014. Length: 12.5 cm (5.0 inches). Catch, photograph, 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 photographs of juveniles is limited.

The Ocean Triggerfish, Canthidermis sufflamen, is a member of the Triggerfish or Balistidae Family, and is known in Mexico as sobaco lija. 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 Oceans.

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 juvenile; their first dorsal fin has 3 spines that can be locked erect with the second spine being half the size of the first; their second dorsal spine has 26 or 27 rays; 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. They are covered with thick leathery skin and are fully scaled. Their lateral line is inconspicuous.

The Ocean Triggerfish is a pelagic species found in and around floating objects including Sargassum beds at depths between 6 m (20 feet) and 73 m (240 feet). They reach a maximum of 65 cm (2 feet 2 inches) in length and 6.1 kg (13.5 lbs) in weight. As of January 1, 2023, the International Game Fish Association world record stood at 6.12 kg (13 lbs 8 oz) with the fish caught in coastal waters off Pompano Beach, Florida in March 1995. 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. The Ocean Triggerfish is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Ocean Triggerfish is a resident of all Mexican waters of the Atlantic Ocean including the Gulf of Mexico and the east coast of the Yucatán Peninsula in the Caribbean.

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).

From a conservation perspective the Ocean Triggerfish is currently considered to be of Least Concern with stable, widely distributed populations. They are not a targeted commercial 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. 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.