Longspine Squirrelfish

Longspine Squirrelfish, Holocentrus rufus

Longspine Squirrelfish, Holocentrus rufus. Fish caught at THE Elbow, 70 miles west of Tarpon Springs, Florida, January 2019. Length: 25 cm (9.8 inches). Catch, photograph and identification courtesy of George Brinkman, Guelph, Ontario, Canada.

Longspine Squirrelfish, Holocentrus rufus. Fish caught in coastal waters off the Cayman Islands, July 2016. Length: 33 cm (13 inches). Catch, photograph and identification courtesy of Ryan Crutchfield, Tampa, Florida.

Longspine Squirrelfish, Holocentrus rufus. Fish caught from coastal waters off Belize, June 2020. Length: 33 cm (13 inches). Catch, photograph, and identification courtesy of Josh Leisen (joshadventures.com), Gaylord, Michigan.

The Longspine Squirrelfish, Holocentrus rufus, whose common Spanish name is candil de rufo, is a member of the Squirrelfish or Holocentridae Family, known collective as candiles in Mexico. Globally, there are two species in the genus Holocentrus, both found in Mexican waters of the Atlantic Ocean and both are found in this Website.

The Longspine Squirrelfish has an oblong fusiform compressed “perch-like” slender body with a pointed head that has large eyes, a large mouth that open in the front and extends past the middle of the pupil, and numerous spines including a large long spine at the upper corner of the gill cover. The head and body are red in color and abruptly transition to silvery ventrally; the anal fin, soft dorsal fin, pectoral fin and pelvic fins are reddish; caudal fin base and fin is yellowish white, the spiny dorsal fin is reddish with white triangular blotches between each spine. Their anal fin has 3 or 4 spines, the third of which is elongated, and 9 to 11 rays; their caudal fin is deeply forked with an elongated upper lobe and pointed tips; and, their dorsal fin has 11 spines and 14 to 16 rays, is continuous with the initial rays being elongated. They have 15 to 18 gill rakers. Their body is covered with rough scales giving them a sandpaper-like feel and the lateral line is complete.

Longspine Squirrelfish reside in coral reefs in dark crevices and emerge at night and move to sandy bottoms and grass beds at night for feeding. They are found at depths up to 300 m (1,000 feet) but are most common at depths between 30 m (100 feet) and 60 m 200 feet). They reach a maximum of 44 cm (17 inches) in length. They prey upon brittle stars, crabs, gastropods, mollusks and shrimp. During the day they hide in dark crevices to avoid predation. They will defend these territories, individually or in groups, with visual and acoustic displays. They have the ability to survive for long periods of time in traps and in highly polluted waters. Reproduction is believed to involve batch spawning, with each female releasing 50,000 to 250,000 eggs in open water with pelagic eggs and larvae that settle out in several weeks. The juveniles are thin and silvery pelagics that are seldom seen by humans.

The Longspine Squirrelfish 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 Longspine Squirrelfish is most likely confused with the Squirrelfish, Holocentrus ascensionis (a uniformly colored dorsal fin without the white triangular spots at the upper margin).

From a conservation perspective the Longspine Squirrelfish is currently considered to be of Least Concern with stable, widely distributed populations. They are edible and sold commercially on a limited basis. They are also utilized by the aquarium trade and commonly found in pubic aquariums due to the beautiful red coloration and distinctive large eyes.