Raggedfin Parrotfish, Chlorurus rhakoura Randall & Anderson 1997


A Raggedfin Parrotfish, Chlorurus rhakoura, at Cape Preston, north Western Australia, May 2016. Source: Tony Ayling / iNaturalist.org. License: CC By Attribution-NonCommercial

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, excised rays on the caudal fin giving the fin margins a 'ragged' appearance, a scalloped margin on the pectoral fin, and a very long second-last dorsal- and anal-fin ray. The species also has conspicuous white dental plates (fused teeth), with the lips only about one-quarter of the teeth. 
Smaller fish have dull bluish-green body scales with a dark purplish to deep blue margin.

Cite this page as:
Bray, D.J. 2020, Chlorurus rhakoura in Fishes of Australia, accessed 12 Jul 2020, http://136.154.202.208/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, and Cape Preston, Western Australia. The species occurs elsewhere in the Mediterranean Sea (Sicily) and the Eastern Indian Ocean: Sri Lanka, Andaman Sea and Indonesia.
Individuals or small schools inhabit inshore reefs in areas of high coral cover.

Features

Dorsal fin IX,10; Anal rays III, 9 (first spine very small and slender); Pectoral fin 14-15, the uppermost ray 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

Bray, D.J. 2020

Resources

Atlas of Living Australia

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 2012: e.T190767A17775837. https://dx.doi.org/10.2305/IUCN.UK.2012.RLTS.T190767A17775837.en. Downloaded on 16 December 2019.

Choat, J.H, Klanten, O.S., van Herwerden, L., Robertson, D.S. & Clements, K.D. 2012. Patterns and processes in the evolutionary history of parrotfishes (Family Labridae). Biological Journal of the Linnean Society 107(3): 529-557 https://doi.org/10.1111/j.1095-8312.2012.01959.x

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

Insacco, G. & Zava, B.M. 2017. Chlorurus rhakoura Randall & Anderson, 1997 (Perciformes, Scaridae), an Indo-Pacific fish new to the Mediterranean Sea. Mediterranean Marine Science 18(2): 285-291 http://dx.doi.org/10.12681/mms.2139

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:Hermaphrodite

Conservation:IUCN Least Concern

Depth:1-30 m

Habitat:Reef associated

Max Size:44 cm SL

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