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 bulbous fleshy protuberance on the forehead of adults, excised rays on the caudal fin giving the fin margin 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 covering only about one-quarter of the teeth.
Smaller fish have dull bluish-green body scales with a pinkish to purplish bar on each scale.
Smaller fish have dull bluish-green body scales with a pinkish to purplish bar on each scale.
Cite this page as:
Bray, D.J. 2021, Chlorurus rhakoura in Fishes of Australia, accessed 09 Dec 2023, https://fishesofaustralia.net.au/home/species/4933
Raggedfin Parrotfish, Chlorurus rhakoura Randall & Anderson 1997
More Info
Distribution |
Recorded in the Australia region from Exmouth to Geographe Shoals, Western Australia. Elsewhere the species occurs in the Mediterranean Sea (Sicily) and the Indian Ocean: Bangladesh, 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 Parrotfish, Chlorurus 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 (= rag) and oura (= 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. 2021 |
Resources |
Raggedfin Parrotfish, Chlorurus rhakoura Randall & Anderson 1997
References
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
Hasan, M.E. & Parvej, M.R. 2020. Range extension of parrotfishes Scarus zufar and Chlorurus rhakoura (Teleostei: Scarinae) to Bay of Bengal, Bangladesh. Journal of the Ocean Science Foundation 36: 84–90 https://doi.org/10.5281/zenodo.4399975
Hutchins J.B. 2004. Fishes of the Dampier Archipelago, Western Australia. Records of the Western Australian Museum Supplement 66: 343–39.
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.