bluespotted surgeonfish
Ctenochaetus marginatus
Small surgeonfish of shallow reefs, with bright blue spots on the head and body. It is almost never caught on rod and is more valuable for the aquarium than for the hook.
Also called: cirurgião-de-pintas-azuis, navajón estriado, bluespotted surgeonfish
- maximum
- 27 cm
- record/max.
- 0.4 kg
- depth
- 9–12 m
who is the bluespotted surgeonfish
Small fish of the surgeonfish family (Acanthuridae), reaching 27 cm, with a short, tall, disk-shaped body. It lives on shallow reefs facing the open sea and in surf zones, in small schools, mainly between 9 and 12 m. It occurs in islands of the central and western Pacific and, in the eastern Pacific, at Clipperton Island, Cocos Island (Costa Rica) and Gorgona (Colombia), with a record also in Panama. It feeds on a film of algae that grows on the rocks. Like all surgeonfish, it has a movable spine on the tail stalk. In fishing it is reef bycatch, and it is valued mainly for the aquarium.
Essential profile. Identification, where it occurs and rules, with data from FishBase and the cited regulations. Season, time of day, technique and bait are added once we have a good source for the bluespotted surgeonfish.
identification
Short, tall body, with bright blue spots covering the head, body and pectoral fins, and longitudinal blue stripes on the dorsal, anal and caudal fins. The blue spots are the main mark for recognizing it among the surgeonfish of the region. Like all surgeonfish, it has a movable spine on each side of the tail stalk, and it is small, up to 27 cm.
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Each card shows the day's index (0 to 100) and, below it, a strip with the index for each hour, from 0h to 23h. from poor to excellent.
Essential profile: the index uses a general fish model (weather, sun, moon and tide), without a season or time of day specific to this species.
where found
Species of the central and western Pacific that reaches the Americas at the Cocos Islands (Costa Rica), Gorgona (Colombia) and Clipperton, with a record also in Panama, on shallow reefs.
Habitat: Shallow reefs facing the open sea and surf zones, generally from 9 to 12 m.
rules for the bluespotted surgeonfish
Summary of the regulations we found, with the source for each. Rules change; before keeping or transporting fish, check with the state environmental agency.
We found no species-specific rule beyond the region's general rules.
catch and release
catch and release Releasing the fish alive, quickly and with a wet hand. During a closed season it isn't always allowed: what the regulation says applies.
Not venomous. Like all surgeonfish, it has a movable spine on the tail stalk that can cut; handle it with care.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.02089, b = 2.95; FishBase (relação peso-comprimento bayesiana, estimativa da própria espécie)). It's an average: a fat or lean fish can vary by 10% to 20%.
estimated weight
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sources and references
Essential profile: size, length-weight, depth, countries and conservation come from FishBase and the cited regulations, and the texts were written from those sources. Season, time of day, sensitivities, technique and baits and lures are not included yet, because we did not find a good source for this species.
- scientific FishBase: Ctenochaetus marginatus (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Ctenochaetus marginatusNames by country and language.