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Longspine Squirrelfish

Holocentrus rufus

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Longspine Squirrelfish (Holocentrus rufus): Red squirrelfish with white triangular patches behind dorsal spine tips and a pale yellow-white tail.
Original identification illustration of Longspine Squirrelfish. Features may vary.

Fun facts for your next surface interval

  • The white triangles behind the dorsal spine tips are a key clue, not glare to edit away.
  • The upper tail lobe extends farther than the lower lobe.
  • The reported depth range extends well beyond recreational scuba, although the species also occurs shallowly.

Florida and local context

Florida Keys region; Palm Beach occurrence not verified in the cited museum checklist: Smithsonian species data report includes Florida Keys-region occurrence coordinates, for example [[24.4117, -82.975], [24.4298, -82.6662]]. Lake Worth Lagoon row has no verified mark; potential only.

Documented regional presence is not a guarantee of an encounter or a measure of how common this animal is at your dive site.

How to recognize this animal

The most useful mark is the row of bright white triangular patches immediately behind the tips of the red dorsal spines. The head and body are red, while the tail base and tail are yellowish white. A large eye, pointed head and long cheek-corner spine complete the characteristic Holocentrus outline. Include the dorsal in an identification photograph.

Size and life stages

A maximum of 44 centimeters, roughly 17 inches, is reported. Size overlaps extensively with the squirrelfish Holocentrus adscensionis and cannot reliably distinguish them. The long narrow tail base and deeply forked tail, with its longer upper lobe, add a recognizable profile. The front rays of the soft dorsal form an elongated point behind the spiny section.

Habitat and where to look

Reef habitats support this species, with Smithsonian records from one to 330 meters. That range should be read as a biological record, not a dive itinerary. An observer on a shallow reef should look for the dorsal triangles in available views of sheltered red fishes, without entering a confined overhang or disturbing its occupants.

Range and local context

The documented range extends from North Carolina through the Caribbean and into Brazil. Smithsonian distribution points document the Florida Keys region. Florida Museum lists this species only as a potential, unverified Lake Worth Lagoon occurrence; it is not a confirmed Palm Beach record in that checklist. This broader Florida inclusion should not be read as a promise of a local encounter.

What is on the menu?

Recorded prey include crustaceans, mollusks, small fishes and echinoderms. Its food therefore comes from several animal groups rather than a single reef organism. The large mouth is compatible with taking such prey, but the exact item swallowed during a brief feeding movement may be impossible to identify. Describe the observed strike without assigning an unsupported prey species.

Daily habits and behavior

The white dorsal triangles can remain conspicuous when the red body appears duller at depth. Fin folding can conceal them entirely, so an apparently plain dorsal in one photograph is inconclusive. Head spines, rough scales and a serrated bony surface are structural traits shared with its close relatives. They help identify the group but do not replace the color-pattern comparison.

Mating and the next generation

Smithsonian lists pelagic eggs and larvae, indicating an open-water early stage before the reef-associated adult life. A group beneath a ledge is not evidence of a guarded nest. The reviewed references do not establish a local monthly spawning calendar, and no breeding season is inferred from the species' broad geographic or depth range.

Look-alikes and identification traps

Compare Holocentrus adscensionis carefully: it has a yellowish spiny dorsal without the repeated white triangular patches. Blackbar soldierfish have a blunter head, deeper body and dark gill-cover band instead of the long cheek spine. If the dorsal is hidden, label the photograph at the group level until another view provides the distinguishing detail.

Observe without disturbing

Remain outside the shelter and allow the fish to choose whether to emerge. Never use a pointer to lift a fin or move the animal; the cheek and dorsal spines make handling especially inappropriate. A photograph showing the white dorsal patches and yellow-white tail together is preferable to a close-up of the eye alone.

Harvest, protection and eating safety

No spearing; no take in John Pennekamp Coral Reef State Park

Can it be hunted or harvested?

Longspine Squirrelfish (Holocentrus rufus) is not the blackbar soldierfish specifically listed for ornamental live collection. Do not apply a blanket live-only rule to every member of Holocentridae. In Florida state waters, ordinary lawful recreational harvest is subject to a saltwater license unless exempt and the default limit of two fish or 100 pounds per person per day, whichever is greater. This is a legal ceiling, not a recommended catch. Local closures, legal gear and any applicable federal rules still control.

Florida seasons and areas

Taking, killing or possessing this squirrelfish is prohibited in John Pennekamp Coral Reef State Park under FAC 68B-5.002(1)(kk), which covers all Holocentridae. No species-specific statewide annual closed months or size limit were identified in the current FWC rules reviewed; that does not mean every location is open year-round. Check the precise sanctuary, park and refuge zone and state-versus-federal jurisdiction before taking. The designated Western Dry Rocks area closes to all fishing April 1 through July 31 annually. This guide does not authorize collecting at the Blue Heron Bridge dive site.

Can it be speared?

No. FWC specifically prohibits spearing squirrelfish as an ornamental reef-fish family; the absence of this Holocentrus species from the live-collection list does not remove that separate prohibition. Location restrictions independently apply, including near public swimming beaches, qualifying piers/bridges and jetties, in parks, and the specified Monroe County area. Powerheads, bangsticks and rebreathers are prohibited for spearfishing.

Is it safe to eat?

No species-specific food-safety clearance is established here. Check Florida DOH advisories for the actual species and capture water before eating, especially for children or people who are pregnant or may become pregnant. Do not apply freshwater perch or black sea bass advice merely because the common name sounds similar. Legal harvest does not rule out mercury or marine toxins, and cooking does not remove ciguatoxin.

Before you act: This recreational overview is not permission to collect or spear at your dive site. Confirm the species, date, management area, state or federal waters, gear, licenses and current local closures. Identification artwork cannot establish an identification or guarantee seafood safety.

Official rules and health guidance

Reviewed 2026-11-10. Rules and advisories can change; check the linked authorities before harvesting or eating.

Sources and review

Reviewed 2026-11-10.

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