Snorkel Hawaii - Whitebar Surgeonfish

Average Weight/Length

Max length : 25.0 cm TL male/unsexed

Family, Genus, Class & Etymology

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.

Location Habitat

Inhabits primarily boulder-strewn areas of surge zone and browses on filamentous algae. Benthopelagic. Often in schools.

Biology & Physical Description

Dorsal spines (total): 9; Dorsal soft rays (total): 25-27; Anal spines: 3; Anal soft rays: 23 - 25. A whitish bar broadly bordered by dark brown from origin of dorsal fin across operculum. Caudal fin without a white posterior margin. Caudal concavity 10.5 to 12 times in SL. Body depth 1.7 to 1.8 times in SL

Geographic Species Map (Fishbase.org Map)

Summary of Distribution: Western Central Pacific: primarily anti-equatorial; Mariana Islands, southern Japan, Marcus Islands, and the Hawaiian Islands in the north and New Caledonia, Rapa (Austral Islands), and Tuamoto Islands, Pitcairn group, and Easter Island in the south.

Whitebar Surgeonfish