Acanthurus triostegus triostegus   (Linnaeus,  1758) (Fish)
Organism information awaits expert curation
Class: Actinopterygii

Image copyrights: The Nature Conservation and Aquatic Sciences Service

Size: 14-131 mm

Color: Head and body grayish to light brownish, yellowish white on lower sides, the two colors often separated by a brownish undulating stripe from chin to end of anal in large specimens. Five dark cross bands on sides and two elongate spots, one above the other on caudal peduncle. Dorsal and anal grayish to dark. Caudal grayish, hind border pale white. Pectoral hyaline. Median rays of ventral dusky to grayish, rest of the fin pale.

Head 3.1-3.4 in standard length, 3.8-4.2 in total length. Depth of body 1.8-2.1 in standard length, 2.2-2.5 in total length. Eye diameter 3.3-4.0 in head, 1.8-2.1 in snout and 1.2-1.3 in convex interorbital space. Teeth deeply lobate, 6 to 8 on each side of both jaws. First spine of dorsal about one third of second, spines progressively increasing in length to the 6th to 9th, they being subequal. First anal fin spine short, second spine about 3/4th of the third, it being equal to longest dorsal fin spines. Pectoral fin about 1/2 eye diameter shorter than head, ventral fin shorter than pectoral. Caudal fin truncate.
Number of spines and rays in the dorsal fin: IX, 22-23; number of spines and rays in the anal fin: III, 20-21; number of rays in the pectoral fin: ii, 13-14; number of spines and rays in the ventral fin: I, 5; number of scale rows along the lateral line: 150-158; number of horizontal scale rows usually counted from origin of the dorsal fin to the lateral line and from anal origin to the lateral line: 17-19+70-75.

Remarks: Values in above description denote proportions.

Synonym (s)
Chaetodon triostegus Linnaeus, 1758
Acanthurus triostegus Day, 1878
Acanthurus triostegus triostegus Jones, 1969

Common Name (s)
• Rabolu
• Nelalan
• Kurichil
Economic Importance and Threats

Habitat:  Reef Associated


• Lakshadweep, Agatti INDIA
• Lakshadweep, Amini INDIA
• Lakshadweep, Andrott INDIA
• Lakshadweep, Bitra INDIA
• Lakshadweep, Chettalatt INDIA
• Lakshadweep, Kadamatt INDIA
• Lakshadweep, Kalpeni INDIA
• Lakshadweep, Kavaratti INDIA
• Lakshadweep, Minicoy INDIA
• Lakshadweep INDIA
• Lakshadweep, Agatti INDIA (Record: 01/1987-04/1987)
• Lakshadweep, Amini INDIA (Record: 01/1987-04/1987)
• Lakshadweep, Bangaram INDIA (Record: 01/1987-04/1987)
• Lakshadweep, Bitra INDIA (Record: 01/1987-04/1987)
• Lakshadweep, Kadamatt INDIA (Record: 01/1987-04/1987)
• Lakshadweep, Chettalatt INDIA (Record: 01/1987-04/1987)
• Lakshadweep, Kalpeni INDIA (Record: 01/1987-04/1987)
• Lakshadweep, Kavaratti INDIA (Record: 01/1987-04/1987)
• Lakshadweep, Kilttan INDIA (Record: 01/1987-04/1987)
• Lakshadweep, Minicoy INDIA (Record: 01/1987-04/1987)

Literature Source(s)
  • Jones, S and Kumaran, M (1980) Fishes of the Laccadive Archipelago The Nature Conservation and Aquatic Sciences Service, Trivandrum, Kerala 760 pp Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Kumaran, M; Mohan, RSL and Murty, VS (1989) Other fin-fish resources Marine living resources of the union territory of Lakshadweep: An indicative survey with suggestions for development Bulletin of Central Marine Research Institute CMFRI 43 65-72 Available at -

Page last updated on:2011-04-20

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