- Classification
- ACTINOPTERYGII
- PERCIFORMES
- LABRIDAE
- Choerodon
- rubescens
Baldchin Groper, Choerodon rubescens (Günther 1862)
A male Baldchin Groper, Choerodon rubescens, at the Houtman Abrolhos, Western Australia. Source: Graham Edgar / Reef Life Survey. License: CC BY Attribution
A large wrasse with protruding tusk-like teeth in both jaws, and a distinctive white chin and a white patch on the pectoral-fin base. Baldchin Groper vary in colour ranging from yellowish-brown in juveniles to pinkish-grey or greenish-blue in large males.
Video of a Baldchin Groper foraging for food by disturbing the sediment with its pectoral fins.
Baldchin Groper, Choerodon rubescens (Günther 1862)
More Info
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Distribution |
Endemic to Western Australia between Ningaloo Reef and Cape Leeuwin in the south. The species is most abundant in the Houtman Abrolhos, about 70 km west of Geraldton, although Baldchin Groper are becoming increasingly common in the Rottnest-Mandurah region further south. Adults inhabit coastal and offshore reefs, while juveniles often shelter in shallow weedy areas near reefs. |
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Feeding |
Feeds on benthic invertebrates such as squid, octopus, sea urchins and sometimes crustaceans. |
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Biology |
Baldchin Groper are protogynous hermaphrodites, and begin their adult life as females before changing sex during their life cycle to become males. Although they are solitary or live in small groups, during the breeding season, individuals may form large spawning aggregations of up to a hundred fish.They usually mature as females at around 2-3 years of age and 27 cm TL. Theyproduce eggs for several uyears, before changing sex to male at 8-12 years of age and 48-55 cm TL. While usually solitary or inclined to reside in small groups, baldchin have occasionally been observed to ‘aggregate’ or gather in large groups of up to one hundred fish to spawn. At these times, they may be vulnerable to high levels of fishing. Spawning at the Abrolhos Islands usually occurs from early spring to mid-summer, peaking from November to early January. Females are serial spawners, releasing eggs in a series of batches during the breeding season. |
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Fisheries |
Highly prized by both commercial and recreational fishers, and considered very good eating. The minimum legal size limit for retention (commercial and recreational) is 40 cm, which is above the length at sexual maturity of about 29 cm. |
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Remarks |
Baldchin Groper are being found further south along the Western Australian coast due to ocean warming along the Western Australian coast. |
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Etymology |
The specific name rubescens is from Latin ruber (= red, reddish) and -escens (= becoming) in reference to the reddish colour of the preserved skin of the type specimen: "the ground-colour appears to be reddish, without other markings." |
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Species Citation |
Choerops rubescens Günther 1862, Cat. fishes Brit. Mus. 4: 97. Type locality: Houtman Abrolhos, Western Australia. |
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Author |
Bray, D.J. 2021 |
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Resources |
Baldchin Groper, Choerodon rubescens (Günther 1862)
References
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Cure, K., Hobbs, J. & Harvey, E. 2015. High recruitment associated with increased sea temperatures towards the southern range edge of a Western Australian endemic reef fish Choerodon rubescens (family Labridae). Environmental Biology of Fishes 98: 1059–1067. https://doi. org/10.1007/s10641-014-0339-3
Cure, K., Hobbs, J., Langlois, T., Abdo, D., Bennett, S. & Harvey, E. 2018. Distributional responses to marine heat waves: Insights from length frequencies across the geographic range of the endemic reef fish Choerodon rubescens. Marine Biology 165(1): 1–14. https://doi. org/10.1007/s00227-017-3259-x
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Edgar, G.J. 2008. Australian Marine Life: the plants and animals of temperate waters. Sydney : Reed New Holland 2nd edn, 624 pp.
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Fairclough, D.V., Clarke, K.R., Valesini, F.J., Potter, I.C. 2008. Habitat partitioning by five congeneric and abundant Choerodon species (Labridae) in a large subtropical marine embayment. Estuarine and Coastal Shelf Science 77: 446–456
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Gomon, M.F. 2017. A review of the tuskfishes, genus Choerodon (Labridae, Perciformes), with descriptions of three new species. Memoirs of Museum Victoria 76: 1-111. http://doi.org/10.24199/j.mmv.2017.76.01
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Hutchins, J.B. 1990. Fish survey of South Passage, Shark Bay, Western Australia. pp. 263-278 in Berry, P.F., Bradshaw, S.D. & Wilson, B.R. (eds). Research in Shark Bay: Report of the France-Australe Bicentenary Expedition Committee. Perth : Western Australian Museum.
Hutchins, J.B. 1994. A survey of the nearshore reef fish fauna of Western Australia's west and south coasts — The Leeuwin Province. Records of the Western Australian Museum, Supplement 46: 1-66 figs 1-6
Hutchins, J.B. 1997. Checklist of fishes of the Houtman Abrolhos Islands, Western Australia. pp. 239-253 in Wells, F. (ed.) The Marine Fauna and Flora of the Houtman Abrolhos Islands, Western Australia. Perth : Western Australian Museum.
Hutchins, J.B. 2001. Biodiversity of shallow reef fish assemblages in Western Australia using a rapid censusing technique. Records of the Western Australian Museum 20: 247-270
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Nardi, K., Jones, G.P., Moran, M.J. & Cheng, Y.W. 2004. Contrasting effects of marine protected areas on the abundance of two exploited reef fishes at the sub-tropical Houtman Abrolhos Islands, Western Australia. Environmental Conservation 31(2): 160-168. https://doi.org/10.1017/S0376892904001274
Nardi, K., Newman, S.J., Moran, M.J. & Jones, G.P. 2006. Vital demographic statistics and management of the baldchin groper (Choerodon rubescens) from the Houtman Abrolhos Islands. Marine and Freshwater Research 57: 485-496. https://doi.org/10.1071/MF05187
Puckridge, M., Last, P.R. & Andreakis, N. 2015. The role of peripheral endemism and habitat associations in the evolution of the Indo-West Pacific tuskfishes (Labridae: Choerodon). Molecular Phylogenetics and Evolution 84: 64-72
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