page_title: Brownback trevally
section_title: Description
hierarchical_section_title: Brownback trevally / Description
caption_attribution_description: English: Taken from Palau
context_page_description: The brownback trevally, also known as the brown-backed trevally, is a species of small inshore marine fish classified in the jack family, Carangidae. The brownback trevally is distributed in two populations through the tropical waters of the Indo-west Pacific region, ranging from the Persian Gulf east to India, South East Asia and the Indonesian islands. The species is distinguished from similar species by its completely scaled breast and black-tipped second dorsal fin, and is known to reach a maximum length of 25 cm. The brownback trevally inhabits inshore waters including bays and estuaries, where it preys on demersal crustaceans and small fish. Other aspects of its biology are poorly known, and it is of minor importance to fisheries, occasionally caught by hook and line or trawls. William Smith-Vaniz has recently suggested the two distinct populations may actually represent two distinct species.
context_section_description: The brownback trevally is a relatively small species of carangid, growing to a maximum recorded length of 25 cm, but is much more common at lengths less than 16 cm. The species has a similar body profile to other trevallies in the same genus, having an elongate, compressed form with the dorsal and ventral profiles approximately equal in convexity. The dorsal fin is in two parts, the first consisting of 8 spines while the second has 1 spine and 21 to 24 soft rays, with both dorsal fins of approximately equal height. The anal fin has two anteriorly detached spines followed by 1 spine and 18 to 20 soft rays. The lateral line has a moderate anterior arch, with the straight and arched sections being nearly equal in length. The straight part of the lateral line has 4 to 12 scales followed by 23 to 34 scutes. The breast is nearly completely scaled, occasionally having a partially naked midventral area, which rarely extends the entire length of the breast. In the western population, all individuals have this narrow naked midventral area extending the entire length of the breast. Both jaws have an irregular row of small conical teeth, with the upper jaw also having a narrow band of teeth anteriorly. The gill raker count also varies between the two populations, with the eastern population having 32 to 37 in total, while the western population has 40 to 47. There are 24 vertebrae.
  The brownback trevally is silvery blue-grey dorsally, shading to silvery underneath, sometimes with a broad brassy midlateral zone. There is no dark opercular spot. The distal area of the second dorsal fin lobe is strongly black, usually with a white tip while the remainder of the fin is dusky. The caudal fin is yellow and all other fins are whitish to hyaline.
caption: An anglers catch of brownback trevally
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