Shadow trevally
The shadow trevally (Carangoides dinema), also known as the shadow kingfish, twothread trevally or Aldabra trevally, is a species of inshore marine fish in the jack family Carangidae. The species is patchily distributed throughout the tropical and subtropical waters of the Indian and west Pacific Oceans, from South Africa in the west to Japan and Samoa in the east, reaching as far south as Indonesia and New Caledonia. It is most easily distinguished from similar species by as series of dark rectangular blotches under the second dorsal fin, giving a 'shadowed' appearance, from which its common name is derived. The shadow trevally is a reasonably large fish, growing to 85 cm in length and at least 2.6 kg in weight. It inhabits shallow coastal waters, including reefs, bays, and estuaries, where it takes small fish and benthic crustaceans as prey. Nothing is known of the species' ecology and reproductive biology. It is of little importance to fisheries, and is occasionally taken by bottom trawls and other artisanal fishing gear. Taxonomy and naming The shadow trevally is classified within the genus Carangoides, one of a number of groups of fish referred to as jacks and trevallies. Carangoides is further classified in the family Carangidae, the Carangidae are part of the order Carangiformes. The species was first scientifically described and named by the Dutch ichthyologist Pieter Bleeker in 1851 based on a specimen collected from the waters off Jakarta, located on Java in Indonesia, which was designated to be the holotype. He named this new species Carangoides dinema, with the specific name derived from the Latin dis, meaning two and the Greek nema, meaning thread, referring to the fin anatomy of the species. This classification in Carangoides is still currently considered to be correct, although other authors have at times transferred the species to Caranx and Carangichthys. The species was independently renamed once by David Starr Jordan and Alvin Seale in 1908, who applied the name Caranx deani to the species. This later naming is considered invalid under the ICZN nomenclature rules and is rendered a junior synonym. The species is quite unique in the comparatively simple taxonomic history it has, with other related species often renamed and transferred between genera many times. The species is most commonly termed the 'shadow trevally' or 'shadow kingfish' in reference to a series of small dark blotches positioned on the upper side, underneath the second dorsal fin, giving the appearance of shadow from the fin itself. Other names used for the species include 'two-thread trevally' and 'Aldabra trevally'. Description The shadow trevally is similar in form to a number of other jacks in the family Carangidae, having an almost ovate, strongly compressed body. It is fairly large fish, growing to a maximum known length of 85 cm and a recorded weight of 2.6 kg. The dorsal profile is strongly convex, while the ventral profile is less so, even tending to be concave between the snout and the anal fin, while the nape is elevated and