{{Short description|Species of fish}} {{Speciesbox | image = Brownback Trevally.jpg | status = LC | status_system = IUCN3.1 | status_ref= <ref name="iucn status 20 November 2021">{{cite iucn |author=Smith-Vaniz, W.F. |author2=Carpenter, K.E. |author3=Borsa, P. |author4=Obota, C. |author5=Jiddawi, N. |author6=Yahya, S. |date=2018 |title=''Carangoides praeustus'' |volume=2018 |article-number=e.T20429981A46664084 |doi=10.2305/IUCN.UK.2018-2.RLTS.T20429981A46664084.en |access-date=20 November 2021}}</ref> | taxon = Carangoides praeustus | authority = (Anonymous [ [[Edward Turner Bennett|E. T. Bennett]] ], 1830) | range_map = Carangoides praeustus distribution.PNG | range_map_caption = Approximate range of the brownback trevally | synonyms = * ''Caranx praeustus''<br /><small> Anonymous [Bennett], 1830</small> * ''Caranx ire''<br /><small> [[Georges Cuvier|Cuvier]], 1833</small> * ''Caranx melanostethos''<br /><small>[[Francis Day|Day]], 1865</small> | synonyms_ref = <ref name = "fishbase"/> }} The '''brownback trevally''' (''Carangoides praeustus''), also known as the '''brown-backed trevally''', is a species of small [[inshore]] [[marine (ocean)|marine]] [[fish]] classified in the jack [[Family (taxonomy)|family]], [[Carangidae]]. The brownback trevally is distributed in two populations through the [[tropical]] waters of the [[Indo-pacific|Indo-west Pacific]] region, ranging from the [[Persian Gulf]] east to [[India]], [[South East Asia]] and the [[Indonesia]]n 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 [[bay]]s and [[estuaries]], where it preys on demersal [[crustacean]]s 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 [[trawling|trawls]]. William Smith-Vaniz has recently suggested the two distinct populations may actually represent two distinct species.
==Taxonomy and naming== The brownback trevally is classified within the [[genus]] ''[[Carangoides]]'', one of a number of groups of fish referred to as jacks and trevallies. ''Carangoides'' falls into the jack and horse mackerel family [[Carangidae]], the Carangidae are part of the [[Order (biology)|order]] [[Carangiformes]].<ref name = Nelson5>{{cite book |title=Fishes of the World |edition=5th |author1=J. S. Nelson |author2=T. C. Grande |author3=M. V. H. Wilson |year=2016 |pages=380–387 |publisher=Wiley |isbn=978-1-118-34233-6 |url=https://sites.google.com/site/fotw5th/ |access-date=2019-11-24 |archive-date=2019-04-08 |archive-url=https://web.archive.org/web/20190408194051/https://sites.google.com/site/fotw5th/ }}</ref>
The species was first [[scientific classification|scientifically described]] by an unknown author in a publication entitled 'Memoir of the Life and Public Services of Sir [[Thomas Stamford Raffles]]', in which a chapter was dedicated to fish specimens Raffles had collected. The author is usually presumed to be the English [[zoologist]] [[Edward Turner Bennett]],<ref name = "London">{{cite book | last = Ludwig | first = Albert Carl |author2=Gotthilf Günther | title = Catalogue of the Fishes in the British Museum | publisher = British Museum (Natural History). Dept. of Zoology | year = 1860 | page = 238 }}</ref> but due to a lack of evidence to support this, his name is placed in parentheses as required by the [[International Code of Zoological Nomenclature|ICZN]] code. The species was here published under the name of ''Caranx praeustus'', with the [[holotype]] collected from [[Sumatra]], Indonesia. This classification was later changed to the genus ''Carangoides'' by [[Pieter Bleeker]], where it has remained.<ref name = "London"/> Two [[junior synonym]]s have been applied to the species, ''Caranx ire'' and ''Caranx melanostethos'', which are invalid under ICZN rules. The species [[specific name (zoology)|specific epithet]] ''praeustus'' is [[Latin]]; meaning "burnt at the tip", in reference to its black dorsal lobe.{{Cn|date=January 2021}}
In the last revision of the carangids of the Indo-Pacific, William Smith-Vaniz found that the two separate populations have differing [[gill raker]] counts and breast squamation, leading him to suggest the possibility of these being two separate species. If further study indicates these are two separate species, the name ''Carangoides ire'' should be reinstated, as [[Georges Cuvier]] described a fish from this second western Indian Ocean population as ''Caranx ire''.<ref name = "FAO">{{cite book |editor-last=Carpenter |editor-first=Kent E. |editor2=Volker H. Niem | title = FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Volume 4: Bony fishes part 2 (Mugilidae to Carangidae) | publisher = FAO | year = 2001 | location = Rome |page= 2694 | url = ftp://ftp.fao.org/docrep/fao/009/x2400e/x2400e52.pdf | isbn = 92-5-104587-9}}</ref>
==Description== [[File:Brownback trevally catch.jpg|thumb|left|An anglers catch of brownback trevally]]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.<ref name = "Oman">{{cite book | last = Randall | first = John E. | title = Coastal Fishes of Oman | publisher = University of Hawaii Press | year = 1995 | location = Honolulu | page = 183 | isbn = 0-8248-1808-3 }}</ref> The species has a similar body profile to other trevallies in the same genus, having an elongate, compressed form with the [[anatomical terms of location#Dorsal and ventral|dorsal]] and [[anatomical terms of location#Dorsal and ventral|ventral]] profiles approximately equal in [[wikt:convex|convexity]].<ref name = "FAO"/> The [[dorsal fin]] is in two parts, the first consisting of 8 [[Fish anatomy#Spines and rays|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 [[Anatomical terms of location#Anterior and posterior|anteriorly]] detached spines followed by 1 spine and 18 to 20 [[Fish anatomy#Spines and rays|soft rays]].<ref name = "Oman"/> 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 [[scale (zoology)|scaled]], occasionally having a partially naked midventral area, which rarely extends the entire length of the breast.<ref name = "FAO"/> In the western population, all individuals have this narrow naked midventral area extending the entire length of the breast. Both [[jaw]]s 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]].<ref name = "FAO"/>
The brownback trevally is silvery blue-grey dorsally, shading to silvery underneath, sometimes with a broad [[brass]]y midlateral zone. There is no dark [[operculum (fish)|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]].<ref name = "HK">{{cite book | last = Sadovy | first = Yvonne |author2=Andrew S. Cornish | title = Reef Fishes of Hong Kong | url = https://archive.org/details/reeffisheshongko00sado | url-access = limited | publisher = Hong Kong University Press | year = 2001 | pages = [https://archive.org/details/reeffisheshongko00sado/page/n304 321] | isbn = 978-962-209-480-2 }}</ref>
==Distribution and habitat== The brownback trevally is distributed in two distinct [[Population (biology)|population]]s in the [[tropical]] waters of the [[Indo-Pacific|Indo-west pacific]] region.<ref name = "FAO"/> The western population extends from the waters of [[Iran]] in the [[Persian Gulf]] to the [[Bay of Bengal]] off [[Bangladesh]], with records also from the [[Maldives]] and [[Sri Lanka]]. The eastern population inhabits a wide region in the [[South East Asia]]n and [[Indonesia]]n region, from the [[Gulf of Thailand]] to [[Borneo]], [[Philippines]] and Indonesia.<ref name = "fishbase">{{FishBase | genus = Carangoides | species = praeustus | year = 2019 | month = August}}</ref>
The brownback trevally is a [[coastal]] species, inhabiting both rocky and [[coral reef]]s,<ref name = "HK"/> as well as [[bay]] and [[estuary]] environments.<ref>{{cite journal | last = Hajisamae | first = Sukree |author2=P. Yeesin |author3=S. Chaimongkol | title = Habitat utilization by fishes in a shallow, semi-enclosed estuarine bay in southern Gulf of Thailand | journal = [[Estuarine, Coastal and Shelf Science]] | volume = 68 | issue = 3–4 | pages = 647–655 | year = 2006 | doi = 10.1016/j.ecss.2006.03.020 }}<!--| access-date =2008-11-12 --></ref> The species prefers calm, sheltered waters.{{Cn|date=January 2021}}
==Biology and fishery== The biology of the brownback trevally is known only from a single research study on its diet, and observational evidence recorded by divers. The study was located in the [[South China Sea]], and focused on the diets of two species of [[Sillaginidae|sillaginids]], with investigations into the [[wikt:Special:Search/trophic|trophic]] relationships of fish in the region. It was found the brownback trevally primarily consumes [[shrimp]]s, with lesser amounts of [[calanoid]] [[copepod]]s and small fish also taken.<ref name = "Hajisamae">{{cite journal |last=Hajisamae |first=Sukree |author2=Pun Yeesin |author3=Sakri Ibrahim |date=August 2006 |title=Feeding ecology of two sillaginid fishes and trophic interrelations with other co-existing species in the southern part of South China Sea |journal=Environmental Biology of Fishes |volume=76 |issue=2–4 |pages=167–176 |doi=10.1007/s10641-006-9018-3}}</ref> Observations indicate the fish form schools of up to 13 fish, which patrol reefs, and are inquisitive of divers.<ref name = "HK"/> In [[Hong Kong]] waters, the fish is present from April to October, with a darkening of the fishes colour appearing to indicate [[spawn (biology)|spawning]] occurs in September at this locality.<ref name = "HK"/>
The brownback trevally is of minor importance to fisheries throughout its range, often taken as bycatch in various trawling and hook and line operations. It is generally not distinguished from other trevally species, and no catch statistics are reported. It is also often taken by small artisanal fisheries by various inshore fish traps.<ref name = "FAO"/>
==References== {{Reflist|2}}
==External links== *[http://www.fishbase.org/Summary/SpeciesSummary.php?id=1911 Brownback trevally at Fishbase] *[https://web.archive.org/web/20110716183310/http://research.kahaku.go.jp/zoology/Fishes_of_Libong/data/p033_01b.html Factsheet and picture]
{{Taxonbar|from=Q1860479}}
[[Category:Carangoides|brownback trevally]] [[Category:Marine fauna of South Asia]] [[Category:Fish described in 1830|brownback trevally]]