False scorpionfish

False scorpionfish
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Perciformes
Family:	Centrogenyidae Johnson, 1984
Genus:	Centrogenys Richardson, 1842
Species:	C. vaigiensis
Binomial name
Centrogenys vaigiensis (Quoy and Gaimard, 1824)
Synonyms[1]
Scorpaena vaigiensis Quoy and Gaimard, 1824

False scorpionfish (Centrogenys vaigiensis) are perciform fish, the only species in genus Centrogenys as well as family Centrogenyidae.^[2] They are pale grey or brown and usually grow no longer than 25 centimetres (9.8 in). False scorpionfish are distributed throughout the Indo-West Pacific, bounded by the Ryukyu Islands of Japan to the north and Australia to the south, the Nicobar Islands to the west and New Guinea to the east.

Description

False scorpionfish can grow to a maximum length of 25 centimetres (9.8 in), but are usually no longer than 9.3 centimetres (3.7 in).^[2] The operculum (bony covering of gills) has two spines, the lower of which is more conspicuous.^[3] False scorpionfish have 36 to 44 lateral line scales.^[3]

False scorpionfish have thirteen or fourteen dorsal fin spines and nine to eleven branches dorsal rays.^[3] The base of the anal fin is short, and has three spines and five segmented rays. The second anal fin spine is the longest. The pectoral fins have twelve to fourteen rays, whereas pelvic fins have one spine and three rays.^[3] A membrane connects the inner pelvic ray to the body.^[3]

The body overall is pale brown or grey. The fins may be the same colour or lighter, or even clear.^[3] The ventral side is paler than the dorsal side, and large brown or grey spots mottle the pectoral and pelvic fins and also the forward portion of the anal fin. False scorpionfish feed upon small fishes, shrimps, and crabs.^[3]

Mimicry

The false scorpionfish appears very similar to the true scorpionfish, to the point of originally being described as a species of Scorpaena.^[4] This similarity protects the false scorpionfish from predators, which would not prey upon the very venomous true scorpionfish.

Distribution and habitat

They are brackish-water or marine fish, living in the benthopelagic layer.^[2] Their range encompasses the Indo-West Pacific, from the Nicobar Islands to New Guinea, southwards to northern Australia, and as far north as the Ryukyu Islands of Japan.^[2] False scorpionfish occur on rocky bottoms and reefs, almost always those with ample seagrass covering.^[5] They are most commonly found in shallow waters along the coast.^[2]

Relationship to humans

False scorpionfish have little or no role in commercial fisheries.^[3] However, they are occasionally found in home aquaria.^[2][3]

References

1. ^ "Centrogenys vaigiensis". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=645614. Retrieved 17 February 2010. 
2. ^ ^{a b c d e f} Froese, Rainer, and Daniel Pauly, eds. (2010). "Centrogenys vaigiensis" in FishBase. January 2010 version.
3. ^ ^{a b c d e f g h i} "The Living Marine Resource of the Western Central Pacific". FAO Species Identification Guide for Fishery Purposes (Rome: Food and Agriculture Organization of the United Nations) 4 (Bony fishes part 2). 1999. ISSN 1020-6868. ftp://ftp.fao.org/docrep/fao/009/x2400e/x2400e43.pdf. Retrieved 17 March 2010. 
4. ^ Randall, John E. (2005). "A Review of Mimicry in Marine Fishes". Zoological Studies 44 (3): 302–304. http://www.sinica.edu.tw/zool/zoolstud/44.3/299.pdf. Retrieved 18 March 2010. 
5. ^ Tomascik, Tomas (1997). The ecology of the Indonesian seas, Part 2. Tuttle Publishing. pp. 659. ISBN 9789625931630.