Coral Croucher, Caracanthus unipinna (Gray 1831)


Other Names: Pygmy Coral Croucher

A Coral Croucher, Caracanthus unipinna, from Kouaku, Gambier Islands, French Polynesia, September 2010, USNM 400567 (27 mm SL). Source: Jeffrey T. Williams / Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Fishes. License: CC BY Attribution-Noncommercial-ShareAlike

Summary:
A very cryptic uniformly orange-brown, brown or greyish coral croucher becoming paler below with no deep notch between the spinous and soft-rayed parts of the dorsal fin. The skin is densely covered in tiny elongate sensory papillae giving the fish a furry appearance.

Cite this page as:
Bray, D.J. 2021, Caracanthus unipinna in Fishes of Australia, accessed 05 Dec 2021, https://fishesofaustralia.net.au/home/species/2168

Coral Croucher, Caracanthus unipinna (Gray 1831)

More Info


Distribution

Murion Islands and offshore reefs of north Western Australia, Ashmore Reef in the Timor Sea, and the far northern Great Barrier Reef and reefs in the Coral Sea, to One Tree Island, Queensland; also Cocos (Keeling) Islands and Christmas Island in the eastern Indian Ocean, and the Lord Howe Province in the Tasman Sea. Elsewhere the species is widespread in the tropical, Indo-west-central Pacific.
This highly cryptic species is an obligate coral dweller that shelters deep among branches of Pocillopora, Stylophora and Acropora corals on shallow reefs.

Features

Dorsal fin VII-VIII, 12-13; Anal fin II, 11-12; Pectoral fin 14-15; Pelvic fin I, 1-3. 
Body covered in tiny elongate tubercles: notch in dorsal fin absent.

Feeding

Feeds on coral dwelling fishes and crsutaceans.

Biology

Coral crouchers are obligate coral dwellers that live and feed wholly within branching corals. They are protogynous hermaphrodites.

Remarks

Coral crouchers were previously placed in their own family (Caracanthidae). Shinohara & Imamura (2005) determined that the genus belonged in the family Scorpaenidae.

Similar Species

The Spotted Croucher, Caracanthus maculatus, is tan to pale greyish with numerous small reddish-brown spots and has a deep notch between the spinous and soft-rayed parts of the dorsal fin. 

Etymology

The specific name is from the Latin uni (= one) and pinna (= fin) in reference to the united dorsal fin that lacks a notch between the spinous and soft rayed portions.

Species Citation

Micropus unipinna Gray 1831, Zoological Miscellany 1: 20. Type locality: Pacific.

Author

Bray, D.J. 2021

Resources

Atlas of Living Australia

Coral Croucher, Caracanthus unipinna (Gray 1831)

References


Allen, G.R. 1993. Fishes of Ashmore Reef and Cartier Island. Records of the Western Australian Museum, Supplement 44: 67-91 

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

Allen, G.R., Steene, R.C. & Orchard, M. 2007. Fishes of Christmas Island. Christmas Island : Christmas Island Natural History Association 2 edn, 284 pp. 

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

Allen, G.R. & Smith-Vaniz, W.F. 1994. Fishes of Cocos (Keeling) Islands. Atoll Research Bulletin 412: 1-21 

Bleeker, P. 1879. Contribution à la faune ichthyologique de l'île Maurice. Verslagen en Mededeelingen der Koninklijke Akademie van Wetenschappen (Afdeeling Natuurjunde). Amsterdam 18: 1-23 

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. 

Cole, K.S. & Montgomery, W.L. 2003. Hermaphroditic characteristics of gonad morphology and inferences regarding reproductive biology in Caracanthus (Teleostei, Scorpaeniformes). Copeia 2003(1): 68-80 https://doi.org/10.1643/0045-8511(2003)003[0068:HCOGMA]2.0.CO;2

Gray, J.E. 1831. Description of a new genus of percoid fish, discovered by Mr. Samual Stutchbury, in the Pacific sea, and now in the British Museum. Zoological Miscellany 1: 20 

Hobbs, J-P.A., Newman, S.J., Mitsopoulos, G.E.A., Travers, M.J., Skepper, C.L., Gilligan, J.J., Allen, G.R., Choat, H.J. & Ayling, A.M. 2014. Checklist and new records of Christmas Island fishes: the influence of isolation, biogeography and habitat availability on species abundance and community composition. Raffles Bulletin of Zoology Supplement 30: 184–202 

Hobbs, J-P.A., Newman, S .J., Mitsopoulos, G.E.A., Travers, M.J., Skepper, C.L., Gilligan, J.J., Allen, G.R., Choat, H.J. & Ayling, A.M. 2014. Fishes of the Cocos (Keeling) Islands: new records, community composition and biogeographic significance. Raffles Bulletin of Zoology Supplement 30: 203–219 

Motomura, H. & Matsuura, K. 2016. Caracanthus unipinna. The IUCN Red List of Threatened Species 2016: e.T69793201A69800912. https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T69793201A69800912.en. Downloaded on 22 October 2021.

Poss, S.G. 1999. Families Scorpaenidae, Caracanthidae, Aploactinidae. pp. 2291-2358 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. 4 pp. 2069-2790. 

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. 

Shinohara, G. & Imamura, H. 2005. Anatomical description and phylogenetic classification of the orbicular velvetfishes (Scorpaenoidea: Caracanthus). Ichthyological Research  52(1): 64-76. https://doi.org/10.1007/s10228-004-0256-0

Shinohara, G. & Imamura, H. 2007. Revisiting recent phylogenetic studies of “Scorpaeniformes”. Ichthyological Research 54: 92–99. https://doi.org/10.1007/s10228-006-0379-6

Smith, W.L., Everman, E. & Richardson, C. 2018. Phylogeny and taxonomy of flatheads, scorpionfishes, sea robins, and stonefishes (Percomorpha: Scorpaeniformes) and the evolution of the lachrymal saber. Copeia 106(1): 94-119. https://doi.org/10.1643/CG-17-669

Smith, W.L. & Wheeler, W.C. 2006. Venom evolution widespread in fishes: a phylogenetic rode map for the bioprospecting of piscine venoms. Journal of Heredity 97(3): 206-217 

Tyler, J.C. 1971. Habitat preferences of the fishes that dwell in shrub corals on the Great Barrier Reef. Proceedings of the Academy of Natural Sciences, Philadelphia 123(1): 1-26 figs 1-8 

Wong, M.Y.L, Munday, P.L & Jones, G.P. 2005. Habitat patch size, facultative monogamy and sex change in a coral-dwelling fish, Caracanthus unipinna. Environmental Biology of Fishes 74(2): 141-150

Quick Facts


CAAB Code:37289002

Biology:Hermaphrodite

Conservation:IUCN Least Concern

Danger:Venomous spines

Depth:0-33 m

Habitat:In branching corals

Max Size:5 cm TL

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CAAB distribution map