Bicolour Parrotfish, Cetoscarus ocellatus (Valenciennes 1840)


Other Names: Red-speckled Parrotfish, Spotted Parrot-fish, Two-colour Parrotfish, Two-coloured Parrotfish

A male (terminal phase) Bicolour Parrotfish, Cetoscarus ocellatus, at North Horn, Osprey Reef, Australia. Source: Richard Ling. License: CC by Attribution-Share Alike

Summary:

Like many other wrasses, the Bicolour Parrotfish changes sex and colour during its life cycle.

Identifying features:
Juveniles white with a broad orange band around the head, a black ocellus on the dorsal fin and broad orange submarginal band on the tail.
Females (Initial Phase) are dark purplish to reddish brown, peppered with black spots below, with a large pale yellowish area below the dorsal fin. 
Males (Terminal Phase) are green, with pink spots on head and anterior body above an orange line running from mouth below pectoral-fin base to anal fin, grading to pink scale margins.

Previously called Cetoscarus bicolor in Australia, a species found only in the Red Sea (Randall 2005).


Cite this page as:

Dianne J. Bray, 2011, Bicolour Parrotfish, Cetoscarus ocellatus, in Fishes of Australia, accessed 25 May 2016, http://www.fishesofaustralia.net.au/home/species/390

Bicolour Parrotfish, Cetoscarus ocellatus (Valenciennes 1840)

More Info


Distribution

Widespread in the tropical Indo-Pacific. Known in Australian waters from Ningaloo Reef, Rowley Shoals and Scott Reef (Western Australia), Ashmore Reef, Timor Sea and Lizard Island to the Capricorn Group (Queensland). Also in the Lord Howe Island region.

This coral reef inhabitant lives in clear reef lagoons and on seaward reefs, in depths of 0-40 metres (in Australia). Groups of mature and immature individuals are seen grazing on algae. Small juveniles tend to shelter amongst dense coral, coral rubble and algae.

Features

Meristic features.
Dorsal fin spines/rays: IX, 10
Anal fin spines/rays: III, 9

Feeding

Herbivore - grazes on algae

Biology

Like other parrotfishes, C. ocellatus is a protogynous hermaphrodite, starting life as a female (the 'initial phase'). Adults live in harems with a dominant male and a group of females, and the male maintains a large territory. If the male disappears, the dominant female changes sex and colour to become a brightly-coloured male (the 'terminal phase'). Longevity - at least 20 years of age. 

Conservation

  • EPBC Act 1999 : Not listed
  • IUCN Red List : Least Concern
  • Remarks

    The orange and white juveniles are solitary and resemble flatworms and nudibranchs.

    Etymology

    The species is named ocellatus for the dark ocellus on the dorsal fin of juveniles.

    Species Citation

    Scarus ocellatus Valenciennes 1840, Histoire Naturelle des Poissons 14: 278. Type locality: Caroline Islands, Western Pacific

    Author

    Dianne J. Bray

    Bicolour Parrotfish, Cetoscarus ocellatus (Valenciennes 1840)

    References


    Allen, G.R. 1997. Marine Fishes of Tropical Australia and South-east Asia. Perth : Western Australian Museum 292 pp. 106 pls. (as Cetoscarus bicolor)

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

    Allen, G.R. & Swainston, R. 1988. The Marine Fishes of North-Western Australia. A field guide for anglers and divers. Perth, WA : Western Australian Museum vi 201 pp., 70 pls. (as Cetoscarus bicolor)

    Allen, G.R., Cross, N.J. & Allen, C.J. 2006. Scarinae. pp. 1425-1434 in Beesley, P.L. & Wells, A. (eds). Zoological Catalogue of Australia. Volume 35 Australia : ABRS & CSIRO Publishing Parts 1-3 2178 pp. (as Cetoscarus bicolor)

    Bellwood, D.R. 1994. A phylogenetic study of the parrotfishes family Scaridae (Pisces: Labroidei), with a revision of genera. Records of the Australian Museum, Supplement 20: 1-86 (as Cetoscarus bicolor)

    Bellwood, D.R. 2001. Scaridae. pp. 3468-3492 in Carpenter, K.E. & Niem, T.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 6 pp. 3381-4218. (as Cetoscarus bicolor)

    Choat, J.H., K.D. Clements & W.D. Robbins. 2002. The tropic status of herbivorous fishes on coral reefs. 1. Dietary analyses. Marine Biology 140: 613-623. (as Cetoscarus bicolor)

    Choat, J.H., K.D. Clements & W.D. Robbins. 2004. The trophic status of herbivorous fishes on coral reefs 2: Food processing modes and trophodynamics, Marine Biology 145: 445-454. (as Cetoscarus bicolor)

    Choat, J.H., Pardede, S., Clements, K.D., Rocha, L.A., Russell, B., Myers, R., Lazuardi, M.E., Muljadi, A. & Rahardjo, P. 2012. Cetoscarus ocellatus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. . Downloaded on 15 December 2012.

    Choat, J.H. & Randall, J.E. 1986. A review of the parrotfishes (Family Scaridae) of the Great Barrier Reef of Australia with description of a new species. Records of the Australian Museum 38: 175-228 (as Cetoscarus bicolor)

    Choat, J.H., van Herwerden, L., Robbins, W.D., Hobbs, J.P. & Ayling, A.M. 2006. A report on the ecological surveys undertaken at Middleton and Elizabeth Reefs, February 2006. Report by James Cook University to the Department of the Environment and Heritage. 65 pp. [58] (as C. bicolor)

    Grant, E.M. 1991. Fishes of Australia. Brisbane : EM Grant Pty Ltd 480 pp. (as Cetoscarus bicolor)

    Gust, N., J.H. Choat & J.L. Ackerman. 2002. Demographic plasticity in tropical reef fishes. Marine Biology 140: 1039-1051.

    Gust, N. 2004. Variation in the population biology of protogynous coral reef fishes over tens of kilometres. Canadian Journal of Fisheries and Aquatic Sciences 61: 205-218.

    Hutchins, J.B. 2001. Checklist of the fishes of Western Australia. Records of the Western Australian Museum, Supplement 63: 9-50

    Kuiter, R.H. 1992. Tropical Reef-Fishes of the Western Pacific, Indonesia and Adjacent Waters. Jakarta : PT Gramedia Pustaka Utama 314 pp. pls. (as Cetoscarus bicolor)

    Kuiter, R.H. 1997. Guide to sea fishes of Australia. A comprehensive reference for divers and fishermen. Frenchs Forest, NSW, Australia : New Holland Publishers I-xvii, 434 pp. (as Cetoscarus bicolor)

    Marshall, T.C. 1964. Fishes of the Great Barrier Reef and Coastal Waters of Queensland. Sydney : Angus & Robertson 566 pp. 136 pls. (as Cetoscarus bicolor)

    Parenti, P. & Randall, J.E. 2000. An annotated checklist of the species of the labroid fish families Labridae and Scaridae. Ichthyological Bulletin of the J.L.B. Smith Institute, Grahamstown 68: 1-97 (as Cetoscarus bicolor)

    Parenti, P. & Randall, J.E. 2011. Checklist of the species of the families Labridae and Scaridae: an update. Smithiana, Publications in Aquatic Biodiversity, Bulletin 13: 29-44

    Randall, J.E. 2005. Reef and shore fishes of the South Pacific. New Caledonia to Tahiti and the Pitcairn Islands. Honolulu : University of Hawaii Press 707 pp.

    Randall, J.E., Allen, G.R. & Steene, R. 1990. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 507 pp. figs. (as Cetoscarus bicolor)

    Streelman, J.T., M. Alfaro, M.W. Westneat, D.R. Bellwood & S.A. Karl. 2002. Evolutionary history of the parrotfishes: biogeography, ecomorphology and comparative diversity. Evolution 56: 961-971. 

    Valenciennes, A. in Cuvier, G.L. & Valenciennes, A. 1840. Histoire Naturelle des Poissons. Paris : Levrault Vol. 14 464 pp. pls 389-420.

    Quick Facts


    CAAB Code:37386007

    Biology:Changes sex

    Conservation:IUCN Least Concern

    Depth:0-40 m

    Habitat:Coral Reef

    Max Size:90 cm

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    CAAB distribution map