Bluelined Surgeonfish

Max length : 25.0 cm TL male/unsexed

Family	Acanthuridae
Description	Surgeonfishes, tangs, unicornfishes
Environment	Marine
Etymology	Greek, akantha = thorn + oura = tail
Genus	6
No. of Species	82
Order	Perciformes
Class	Actinopterygii
Reproductive Guild	Nonguarders
Distribution	Circumtropical, especially around coral reefs; five species in the Atlantic, the remaining in the Pacific and Indian oceans. All have a deep compressed body with the eye high on the head and a long preorbital bone. Single unnotched dorsal fin with 4-9 spines and 19-31 rays; anal fin with 2 (only Naso) or 3 spines and 19-36 rays; pelvic fins with 1 spine and 3 (Naso and Paracanthurus) or 5 rays. Very small ctenoid scales. A small terminal mouth with a single row of close-set teeth. Most surgeon fishes graze on benthic algae and have a long intestine; some feed mainly on zooplankton or detritus. Surgeon fishes are able to slash other fishes with their sharp caudal spines by a rapid side sweep of the tail. Pelagic spawners. Many species have bright colors and are popular aquarium fishes.

Inhabits clear lagoon and seaward reefs; often in areas with mixed coral, pavement, rubble and sand substrates. Benthopelagic. Occurs singly or in small groups. Feeds on filamentous algae, diatoms and fine algal film of compacted sand. Relatively uncommon throughout Micronesia; rare on Great Barrier Reef.

Dorsal spines (total): 9; Dorsal soft rays (total): 24-27; Anal spines: 3; Anal soft rays: 23 - 25. Color drab dark brown; spots on body located at the rear base of dorsal and anal fins. Black spot at rear base of dorsal fin not large, its greatest width more than 2 times in eye diameter. White posterior margin of caudal fin very narrow, its width less than 4 times in pupil diameter. No definite black margin around groove of peduncular spine. Body depth 1.8 to 2 times in SL. Maximum standard length about 20 cm

Summary of Distribution: Indo-Pacific: Aldabra and Seychelles to the Hawaiian, Marquesas and Tuamoto Islands; throughout Micronesia.
Note: Distribution range colors indicate degree of suitability of habitat which can be interpreted as probabilities of occurrence (fishbase.org)