Indian threadfish
Indian threadfish | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Perciformes |
Suborder: | Percoidei |
Superfamily: | Percoidea |
Family: | Carangidae |
Genus: | Alectis |
Species: | A. indica |
Binomial name | |
Alectis indica (Rüppell, 1830) | |
Approximate distribution of the Indian threadfish | |
Synonyms | |
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The Indian threadfish, Alectis indica, (also known as the Indian threadfin, diamond trevally, mirror fish and plumed trevally) is a large species of coastal marine fish of the jack family, Carangidae. The species is widespread in the waters of the tropical Indo-West Pacific Ocean, ranging from east Africa to India, Asia, Indonesia and Australia. Adult fish tend to inhabit coastal waters over reefs down to 100 m in depth, while juveniles inhabit a variety of environments including estuaries and seagrass beds. The Indian threadfish is similar to the other two species in the genus Alectis, with a slight concavity in the profile of the head the most obvious distinguishing feature. It is a large species, growing to 165 cm and 25 kg in weight. The species is carnivorous, consuming fishes, cephalopods and crustaceans. The Indian threadfin is of minor commercial importance, and has been the subject of aquaculture in Singapore.
Taxonomy and naming
The Indian threadfish is one of three members of the diamond trevally genus Alectis, which itself is one of 33 genera encapsulated in the jack family, Carangidae. The Carangidae are perciform fishes in the suborder Percoidei.[1]
The species was first recognized and scientifically described by the German naturalist Eduard Rüppell in 1830 under the name Scyris indicus, with the type specimen collected from the Red Sea.[2] After Rüppell's designation, a number of other naturalists unknowingly re-described the species, with the names Hynnis insanus, Caranx gallus and Hynnis momsa applied to the species by the various authors. Rüppell's original classification was also revised; the fish was first placed in Seriolichthys, and finally in the senior genus Alectis by Ogilby in 1913. The species' name has been given as Alectis indicus in the literature, however the genus Alectis is feminine and thus the spelling indica is the correct one.[3][4]
The common name of the species, 'Indian threadfish' or 'Indian threadfin' refers to its distribution which includes Indian waters, and the characteristic elongated dorsal fins in juveniles. Other common names, such as mirror fish and diamond trevally, describe other aspects of the species' appearance.[2]
Description
The body of adults is a silvery blue-green colour above, being darkest on the head and silver below. The upper operculum has a small diffuse dark spot. The long filamentous soft dorsal and anal fins as well as the pelvic fin are a dark blue to black colour, while the others are pale green to hyaline in appearance. Juveniles have 5 to 7 broad dark vertical cross bands through their body.[5]
Distribution and habitat
The species is generally an inhabitant of coastal waters from depths of 20 m to 100 m, although the juveniles may be pelagic, riding ocean currents. In some years currents bring the juveniles as far south as Sydney, Australia where they inhabit of estuaries in the summer, before dying off in the cold winter. The African pompano shows a similar pattern in Australian waters. The juveniles are also known to inhabit estuaries in other regions (including South Africa)[7] as well as seagrass beds.[8] Adults generally inhabit areas of reef below 20 m.[9]
Biology
The Indian threadfish is a predatory fish, consuming of a wide range of fishes, small squids, jellyfish and crustaceans. As with A. ciliaris, the trailing fins of juveniles are thought to resemble jellyfish medusae, causing predators to avoid the young fish. Relatively little is known about reproduction in the species, although observations made in Indonesia show spawning occurs in pairs at daytime between ebbing and flooding tides. The spawning area in this instance was a shoal of 35–45 m, located in a deeper channel between two islands.[10]
Relationship to humans
The Indian threadfish is a commercial fish of minor importance throughout its range, often forming part of artisanal fishery catches. Beach seines and hook-and-line methods are the predominant methods of capture.[4] Archaeological evidence has shown that the species has long been a resource for humans, with prehistoric and more modern sites in the United Arab Emirates yielding the preserved remains of this species, as well as a number of other carangids.[11] The species is commercially farmed in small numbers in Singapore using aquaculture techniques. These farmed fish generally sell for between 7 and 11 US dollars per kg, as high or higher than other jacks farmed in the country.[12] They are also considered quality gamefish, although are not purposely targeted by anglers, and are often taken as bycatch.
Juveniles are moderately popular aquarium fishes, but require fairly large tanks and peaceful neighbours.[13]
References
- ↑ "Alectis indicus". Integrated Taxonomic Information System. Retrieved 21 October 2007.
- ↑ 2.0 2.1 Hosese, D.F.; Bray, D.J., Paxton, J.R. and Alen, G.R. (2007). Zoological Catalogue of Australia Vol. 35 (2) Fishes. Sydney: CSIRO. p. 1150. ISBN 978-0-643-09334-8.
- ↑ http://research.calacademy.org/redirect?url=http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatget.asp&tbl=species&spid=15347
- ↑ 4.0 4.1 4.2 4.3 Carpenter, Kent E.; Volker H. Niem (eds.) (2001). FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Volume 5. Bony fishes part 3 (Menidae to Pomacentridae). Rome: FAO. p. 2684. ISBN 92-5-104587-9.
- ↑ 5.0 5.1 Gunn, John S. (1990). "A revision of selected genera of the family Carangidae (Pisces) from Australian waters". Records of the Australian Museum. Supplement 12: 1–78.
- ↑ 6.0 6.1 Froese, Rainer and Pauly, Daniel, eds. (2013). "Alectis indica" in FishBase. February 2013 version.
- ↑ Blaber, S.J.M.; D.P. Cyrus (1983). "The biology of Carangidae (Teleostei) in Natal estuaries". Journal of Fish Biology (Blackwell Synergy) 22 (2): 173–188. doi:10.1111/j.1095-8649.1983.tb04738.x.
- ↑ Gell, Fiona R.; Mark W. Whittington (2002). "Diversity of fishes in seagrass beds in the Quirimba Archipelago, northern Mozambique". Marine & Freshwater Research (CSIRO) 53 (2): 115–121. doi:10.1071/MF01125.
- ↑ Hutchins, B.; Swainston, R. (1986). Sea Fishes of Southern Australia: Complete Field Guide for Anglers and Divers. Melbourne: Swainston Publishing. pp. 1–187. ISBN 1-86252-661-3.
- ↑ Westernhagen, H. Von (1974). "Observations on the natural spawning of Alectis indicus (Rüppell) and Caranx ignobilis (Forsk.) (Carangidae)". Journal of Fish Biology (Blackwell Synergy) 6 (4): 513–516. doi:10.1111/j.1095-8649.1974.tb04567.x.
- ↑ Potts, D.T. (1997). Before the Emirates: an Archaeological and Historical Account of Developments in the Region c. 5000 BC to 676 AD in Perspectives on the United Arab Emirates. pp. 28–69.
- ↑ Chou, R.; H.B. Lee (1997). "Commercial marine fish farming in Singapore". Aquaculture Research (Blackwell Synergy) 28 (10): 767–776. doi:10.1046/j.1365-2109.1997.00941.x.
- ↑ Pet education. "Indian threadfin". Fish. Foster & Smith, Inc. Retrieved 2007-10-23.