Scientific Name
Acanthurus blochii

Common Name
Ringtail surgeonfish

Biology
Dorsal spines (total): 9; Dorsal soft rays (total): 25-27; Anal spines: 3; Anal soft rays: 24 - 25. Color in life bluish grey with numerous yellowish brown spots which tend to form irregular longitudinal lines; head with narrow irregular stripes; behind eye a yellow spot; brown pectoral fins; base of caudal fin with white bar. Caudal spine large, 3 - 4.4 in head. Stomach gizzard-like. Differs from A. dussumieri by having vertical stripes instead of spots on the blue central area of the caudal fin, from A. mata by having a lunate caudal fin, and from A. xanthopterus by having plain brown to blue-grey pectoral fins (Ref. 1602). The white ring around the base of the tail varies in intensity and may occasionally be absent (Ref. 1602).

Classification

Classified By

Valenciennes, 1835

Class

Ray-finned fishes (Actinopterygii)

Order

Perch-like fish (Perciformes)

Family

Surgeonfishes, tangs, unicornfishes (Acanthuridae)

Distribution

Region

Indo-Pacific

Distribution

Indo-Pacific: East Africa, including the Mascarene Islands (Ref. 37792) to the Hawaiian and Society islands, north to Ryukyu Islands, south to Lord Howe Island.

Range

30°N - 32°S

Environment

Climate

Tropical

Water Temperature From

Unknown °C

Water Temperature To

Unknown °C

Depth From - meters

1 m

Depth To - meters

12 m

Zone

reef-associated

Environment

Marine; reef-associated; depth range 1 - 12 m (Ref. 9710)

Trophic Level

2 s.e. 0.00 Based on food items.

Occurs in Marine / Salt water

True

Occurs in Brackish water

False

Occurs in Fresh Water

False

Occurs on Reefs

True

Is kept in Aquariums

True

Physical Size and Genetics

Maximum Length

45.0 cm

Common Length

Unknown cm

Phylogenetic Diversity Index

PD50 = 0.5000 many relatives (e.g. carps) 0.5 - 2.0 few relatives (e.g. lungfishes)

Human Uses and Population

Human Uses

Fisheries: commercial; aquarium: commercial

Vulnerability

Moderate vulnerability (38 of 100)

Resilience

Low, minimum population doubling time 4.5 - 14 years (Tmax=35; K=0.25)

Threat To Humans

Harmless

IUCN Red List Status

Not Evaluated