Western Gregory, Plectroglyphidodon obreptus (Whitley 1948)

A Western Gregory, Stegastes obreptus, at the Abrolhos Islands, Western Australia. Source: Graham Edgar / Reef Life Survey. License: CC by Attribution

A brown to almost black damselfish becoming paler below, with a yellowish tinge towards the rear of the body, darker scale margins appearing as narrow oblique bands, fins fading to smoky grey distally, a bright blue anterior margin on the pelvic and anal fins, a black blotch behind a narrow white streak near the front of the dorsal fin, and a bright yellow iris.
This species was previously known as Stegastes obreptus.

Cite this page as:
Bray, D.J. 2021, Plectroglyphidodon obreptus in Fishes of Australia, accessed 08 Dec 2022, https://fishesofaustralia.net.au/home/species/386

Western Gregory, Plectroglyphidodon obreptus (Whitley 1948)

More Info


Rottnest Island, Western Australia, around the tropical north to Bountiful Island, Queensland. Elsewhere the species occurs in the tropical, east-Indo-west Pacific.
Inhabits shallow nearshore rocky and coral reefs often in silty areas. Adults are territorial and "farm" patches of filamentous algae that grow on dead coral. 

Species Citation

Pomacentrus obreptus Whitley 1948, Australian Zoologist 11(3): 275. Type locality: Monte Bello Islands, Western Australia.


Bray, D.J. 2021


Atlas of Living Australia

Western Gregory, Plectroglyphidodon obreptus (Whitley 1948)


Allen, G.R. 1991. Damselfishes of the World. Melle, Germany : Mergus Verlag 271 pp. (as Stegastes obreptus)

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

Allen, G. R. 2001. Family Pomacentridae. pp. 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 Stegastes obreptus)

Allen, G.R. & Emery, A.R. 1985. A review of the pomacentrid fishes of the genus Stegastes from the Indo-west Pacific with descriptions of two new species. Indo-Pacific Fishes 3: 1-31 figs 1-5 pls 1-3 (as Stegastes obreptus)

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

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 Stegastes obreptus)

Hutchins, B. 2004. Fishes of the Dampier Archipelago, Western Australia. Records of the Western Australian Museum, Supplement 66: 343–398 (as Stegastes obreptus)

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 (as Stegastes obreptus)

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. (as Stegastes obreptus)

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 (as Stegastes obreptus)

Johnson, J.W. & Gill, A.C. 2005. Reef and shore fishes of Sweers Island, Gulf of Carpentaria. Gulf of Carpentaria Scientific Study Report. Geography Monograph Series. Brisbane: Royal Geographic Society of Queensland. pp. 239-260 (as Stegastes obreptus)

Larson, H.K. & Williams, R.S. 1997. Darwin Harbour fishes: a survey and annotated checklist. pp. 339-380 in Hanley, H.R., Caswell, G., Megirian, D. & Larson, H.K. (eds). The Marine Flora and Fauna of Darwin Harbour, Northern Territory, Australia. Proceedings of the Sixth International Marine Biology Workshop. Darwin : Museum and Art Gallery of the Northern Territory 466 pp. (as Stegastes obreptus)

Larson, H.K., Williams, R.S. & Hammer, M.P. 2013. An annotated checklist of the fishes of the Northern Territory, Australia. Zootaxa 3696(1): 1-293 (as Stegastes obreptus)

Tang, K.L., Stiassny, M.L.J., Mayden, R.L. & DeSalle, R. 2021. Systematics of Damselfishes. Ichthyology & Herpetology 109(1): 258-318. https://doi.org/10.1643/i2020105

Whitley, G.P. 1948. New sharks and fishes from Western Australia. Part 4. The Australian Zoologist 11(3): 259-276 figs 1-7 pls 24-25 See ref at BHL

Quick Facts

CAAB Code:37372136

Depth:2-10 m

Habitat:Reef associated

Max Size:12 cm SL

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