Halfmoon Triggerfish, Rhinecanthus lunula Randall & Steene 1983

Other Names: Cresent Triggerfish, Halfmoon Picassofish, Lunula Triggerfish

A juvenile Halfmoon Triggerfish, Rhinecanthus lunula, in Cabbage Tree Bay, Manly, New South Wales, 2013. Source: John Sear / iNaturalist.org. License: CC By Attribution-NonCommercial

A rare triggerfish with a yellowish to greyish back, a yellow stripe across the cheek, a yellow line on the upper lip, bars across the top of the head running down to the pectoral-fin base, a semi-circular band on the rear of the body, a dark band around the caudal peduncle, and a large black blotch or smudge above the anus. The first dorsal fin is black and the caudal fin has a black area preceded by yellow.

Cite this page as:
Bray, D.J. 2023, Rhinecanthus lunula in Fishes of Australia, accessed 25 May 2024, https://fishesofaustralia.net.au/Home/species/2953

Halfmoon Triggerfish, Rhinecanthus lunula Randall & Steene 1983

More Info


Great Barrier Reef and reefs in the Coral sea, Queensland, to northern New South Wales, with juveniles south to Sydney. Elsewhere this rare triggerfish occurs in the tropical, west-central Pacific: from the Great Barrier Reef, Australia to the Pitcairn Island Group, often on outer reefs.


Dorsal fin III, 25-26; Anal fin 22-24; Pectoral fin 14.
Snout long 2.7-2.8 in SL; caudal peduncle slender; three horizontal row of small forward-curving spines posteriorly on body, the upper row ending at front of caudal peduncle, the lower tow extending to caudal-fin base; caudal fin slightly double emarginate.


Feeds on fishes, benthic invertebrates, algae and detritus.

Species Citation

Rhinecanthus lunula Randall & Steene 1983, Freshwater and Marine Aquarium 6(7): 45, figs 8-10. Type locality: outside barrier reef about 1/4 mile east of Teavaraa Pass, Papara, Tahiti, Society Islands, depth 15 m.


Bray, D.J. 2023


Atlas of Living Australia

Halfmoon Triggerfish, Rhinecanthus lunula Randall & Steene 1983


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

Johnson, J.W. 2010. Fishes of the Moreton Bay Marine Park and adjacent continental shelf waters, Queensland, Australia. pp. 299-353 in Davie, P.J.F. & Phillips, J.A. Proceedings of the Thirteenth International Marine Biological Workshop, The Marine Fauna and Flora of Moreton Bay. Memoirs of the Queensland Museum 54(3) 

Matsuura, K. 2015. Taxonomy and systematics of tetraodontiform fishes: a review focusing primarily on progress in the period from 1980 to 2014. Ichthyology Research 62: 72-113.

Matsuura, K. 2022. Rhinecanthus lunula. The IUCN Red List of Threatened Species 2022: e.T193761A2273033. https://dx.doi.org/10.2305/IUCN.UK.2022-2.RLTS.T193761A2273033.en. Accessed on 03 January 2024.

Matsuura, K. & Shiobara, Y. 1989. A new triggerfish, Rhinecanthus abyssus, from the Ryukyu Islands. Japanese Journal of Ichthyology 36(3): 315-317. https://doi.org/10.11369/jji1950.36.315

Myers, R.F. 1999. Micronesian Reef Fishes. A comprehensive guide to the coral reef fishes of Micronesia. Guam : Coral Graphics vi 330 pp. 192 pls. 

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. 

Randall, J.E., Allen, G.R. & Steene, R. 1997. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 557 pp. figs. 

Randall, J.E. & Steene, R.C. 1983. Rhinecanthus lunula, a new species of triggerfish from the South Pacific. Freshwater and Marine Aquarium 6(7): 45-51 figs 1-10

Quick Facts

CAAB Code:37465072

Conservation:IUCN Least Concern

Depth:10-40 m

Fishing:Aquarium fish

Habitat:Reef associated

Max Size:28 cm TL

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