Raggedfin Parrotfish, Chlorurus rhakoura Randall & Anderson 1997


A Raggedfin Parrotfish, Chlorurus rhakoura. Source: RC Anderson / Randall & Anderson 1997. License: All rights reserved

Summary:
A deep purplish to greyish-brown parrotfish with bright blue margins on the dorsal and anal fins, a prominent bulbous fleshy protuberance on the forehead of adults, and excised rays in the caudal fin giving the tail a 'ragged' appearance.

Cite this page as:
Dianne J. Bray, Chlorurus rhakoura in Fishes of Australia, accessed 23 Nov 2017, http://fishesofaustralia.net.au/Home/species/4933

Raggedfin Parrotfish, Chlorurus rhakoura Randall & Anderson 1997

More Info


Distribution

Recorded in the Australia region from Exmouth to the Monte Bello Islands, Western Australia. The species occurs elsewhere in the Eastern Indian Ocean: Sri Lanka, Andaman Sea and Indonesia.
Inhabits inshore reefs around areas of high coral cover - often in small schools.

Features

Meristic features: Dorsal fin IX,10; Anal rays III, 9 (first spine very small and slender); Pectoral fin 15 (one paratype with 14), the uppermost rudimentary, the second unbranched; Pelvic fin 1,5; Caudal fin (principal rays) 13, the upper and lower unbranched; procurrent caudal rays (upper and lower) 6; Longitudinal scale series 23; Lateral line interrupted but overlapping, the dorsoanterior part with 19 (19-20) scales, and the peduncular part with 5 (5-6) scales; 3 median predorsal scales, 2 rows of scales on cheek.
Caudal-fin rays strongly excised giving the fin a ragged appearance, penultimate anal-fin ray relatively elongate. 

Colour

Dark greyish-brown, body scales a dull bluish-green with very dark purplish edges; or body deep blue, scales greenish with a narrow orange-red bar at base; margins of dorsal and anal fins bright blue.

Similar Species

Similar to the Knothead ParrotfishChlorurus oedema, which may or may not occur in Australia. The Knothead Parrotfish has a rounded tail without 'ragged' fin rays.

Etymology

The specific name  rhakoura is from the Greek rhakos for 'rag', and oura for 'tail', in reference to the ragged posterior margin of the caudal fin.

Species Citation

Chlorurus rhakoura  Randall & Anderson 1997, Journal South Asian Natural History 2(2): 157, Figs. 1-5, Trincomalee, off Lively Rocks, Sri Lanka, depth 20 m.

Author

Dianne J. Bray

Raggedfin Parrotfish, Chlorurus rhakoura Randall & Anderson 1997

References


Allen, G.R. & Erdmann, M.V. 2012. Reef fishes of the East Indies. Perth : Tropical Reef Research 3 vols, 1260 pp.

Choat, J.H., Carpenter, K.E., Clements, K.D., Rocha, L.A., Russell, B., Myers, R., Lazuardi, M.E., Muljadi, A., Pardede, S. & Rahardjo, P. 2012. Chlorurus rhakoura. The IUCN Red List of Threatened Species. Version 2014.1. . Downloaded on 07 July 2014.

Hutchins J.B. 2004. Fishes of the Dampier Archipelago, Western Australia. Records of the Western Australian Museum Supplement 66: 343–39.

Randall, J.E. & Anderson, R.C. 1997. Chlorurus rhakoura, a new species of parrotfish (Perciformes: Labroidei: Scaridae) from Sri Lanka. Journal of South Asian Natural History 2(2): 155-164. PDF

Smith, L.L., Fessler, J.L., Alfaro, M.E., Streelman, J.T. & Westneat, M.W. 2008. Phylogenetic relationships and the evolution of regulatory gene sequences in the parrotfishes. Molecular Phylogenetics and Evolution 49: 136-152.

Westneat, M.W. & Alfaro, M.E. 2005. Phylogenetic relationships and evolutionary history of the reef fish family Labridae. Molecular Phylogenetics and Evolution 36: 370–390.

Quick Facts


CAAB Code:37386037

Biology:Able to change sex

Conservation:IUCN Least Concern

Depth:1-30 m

Habitat:Reef associated

Max Size:44 cm SL

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