Island trevally

{{Short description|Species of ray-finned fish}} {{Speciesbox | image = Carangoides orthogrammus.jpg | status = LC | status_system = IUCN3.1 | status_ref = <ref name = iucn>{{cite iucn | author1 = Smith-Vaniz, W.F. | author2 = Williams, I. | name-list-style = amp | year = 2016 | title = ''Carangoides orthogrammus'' |errata=2017 | volume = 2016 | article-number = e.T20429869A115375664 | doi = 10.2305/IUCN.UK.2016-3.RLTS.T20429869A65927753.en }}</ref> | taxon = Ferdauia orthogrammus | authority = ([[David Starr Jordan|D. S. Jordan]] & [[Charles Henry Gilbert|C. H. Gilbert]], 1881) | range_map = Carangoides orthogrammus distribution.png | range_map_caption = Approximate range of the island trevally | synonyms = *''Caranx orthogrammus'' Jordan & Gilbert, 1882 *''Carangoides orthogrammus'' (Jordan & Gilbert, 1882) *''Carangoides gymnostethoides evermanni'' [[John Treadwell Nichols|Nichols]], 1921 *''Carangoides jordani'' Nichols, 1922 *''Carangoides ferdau jordani'' Nichols, 1922 *''Carangoides nitidus'' [[Margaret Mary Smith|M.M. Smith]], 1972 }}

The '''island trevally''', '''island jack''', '''thicklip trevally''' or '''false bluefin trevally''' (''Ferdauia orthogrammus'') is a widespread species of offshore [[marine (ocean)|marine]] [[ray-finned fish]] classified in the jack [[Family (taxonomy)|family]] [[Carangidae]]. The island trevally is common through the tropical regions of the [[Indian Ocean|Indian]] and [[Pacific Ocean]]s, ranging from [[Mozambique]] and the [[Seychelles]] in the west to [[Hawaii]] and the [[Revillagigedo Islands]] in the central and eastern Pacific. The species is almost completely absent from the [[continental shelves]], instead inhabiting [[Shore|offshore]] islands, where it is found in [[lagoon]]s and on [[reef]] systems. It is a moderately large fish, growing to a maximum recorded length of 75 cm and 6.6 kg in weight, and is distinguishable by its angular snout and yellow spots, as well as more detailed anatomical features. The island trevally often moves in small schools, preying on a variety of small fishes and [[crustacean]]s. It is of moderate importance to [[fisheries]] throughout its range, often taken by [[trawling|trawls]], hook-and-line, and various inshore netting methods, and is sold fresh or [[salting (food)|salted]] at market.

==Taxonomy and naming== The island trevally is classified in the genus ''[[Ferdauia]]'' together with the [[blue trevally]] (''Ferdauia ferdau'').<ref name="ECoF species">{{Catalog of Fishes |genus=Carangichthys |list=species |date=12 February 2026}}</ref><ref name = "fishbase">{{FishBase | Ferdauia | orthogrammus | year = 2026 | month = February}}</ref> ''Ferdauia'' falls into the jack and horse mackerel family [[Carangidae]], and Carangidae is 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 the American [[ichthyologist]]s [[David Starr Jordan|Jordan]] and [[Charles Henry Gilbert|Gilbert]] in 1881 based on a specimen taken from the [[Revillagigedo Islands]], which was designated to be the [[holotype]].<ref name = "Zoocat" >{{cite book | last = Hosese | first = D.F. |author2=Bray, D.J. |author3=Paxton, J.R. |author4=Alen, G.R. | title = Zoological Catalogue of Australia Vol. 35 (2) Fishes | publisher = CSIRO | date = 2007 | location = Sydney | page = 1150 | isbn =978-0-643-09334-8 }}</ref> They named this new species ''[[Caranx]] orthogrammus'', but it was later moved to ''[[Carangoides]]'' after further revision of the family had occurred. The species was independently redescribed a number of times, with the fish placed in [[subspecies]] status twice. [[John Treadwell Nichols]] considered his ''C. ferdau jordani'' to be separate from ''C. orthogrammus'', or possibly a subspecies of the blue trevally, ''C. ferdau'', and was later transferred to ''C. jordani''.<ref>{{cite journal | last = Nichols | first = John T. | title = ''Carangoides jordani'' from the Hawaiian Islands with notes on related fishes | journal = American Museum Novitates | issue = 50 | pages = 1–4 | date = 1922 | hdl = 2246/4619 }}</ref> It was also considered a subspecies or a synonym of the [[bludger (fish)|bludger]], ''C. gymnostethoides'', and was also renamed as ''C. nitidus''. The fish is now considered a separate species, with the subspecies names and the later names rendered invalid under the [[International Code of Zoological Nomenclature|ICZN]] naming rules. The species is commonly known as island trevally in reference to its preferred offshore habitat, with the names thicklip trevally and false bluefin trevally<ref name = "Hutchins" >{{cite book | last = Hutchins | first = B. |author2=Swainston, R. | title = Sea Fishes of Southern Australia: Complete Field Guide for Anglers and Divers | publisher = Swainston Publishing | date = 1986 | location = Melbourne | pages = 1–187 | isbn = 978-1-86252-661-7}}</ref> also used as descriptive names. The [[specific name (zoology)|specific epithet]] means "straight lined" in [[Greek language|Greek]].<ref name = "Zoocat" />

==Description== [[File:Thicklip trevally.JPG|left|thumb|The fleshy lips of the island trevally are a distinguishing feature.]]

The island trevally is a moderately large fish, growing to a maximum recorded length of 75 cm and 6.61 kg in weight.<ref name = "fishbase" /> The species is quite similar to ''F. ferdau'', although the prominent yellow spots serve as a quick identifying feature.<ref name = "Barrier">{{cite book | last = Randall | first = John Ernest |author2=Roger C. Steene |author3=Gerald R. Allen | title = Fishes of the Great Barrier Reef and Coral Sea | publisher = University of Hawaii Press | date = 1997 | page = 161 | isbn = 978-0-8248-1895-1 }}</ref> The island trevally has a compressed oblong shaped body with the [[anatomical terms of location#Dorsal and ventral|dorsal]] profile more convex than the [[anatomical terms of location#Dorsal and ventral|ventral]] profile and the snout usually being slightly rounded.<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 5. Bony fishes part 3 (Menidae to Pomacentridae) | publisher = FAO | date = 2001 | location = Rome | page = 2684 | url = ftp://ftp.fao.org/docrep/fao/009/y4160e/y4160e00.pdf | isbn = 978-92-5-104587-9 }}</ref> The [[dorsal fin]] is in two sections, the first consisting of eight [[Fish anatomy#Spines and rays|spines]] and the second of one spine and 28 to 31 [[Fish anatomy#Spines and rays|soft rays]], with the lobe of the second dorsal fin being slightly [[Ichthyology terms#F|falcate]] in younger individuals, but is always shorter than the head length. The [[anal fin]] has two detached spines followed by one spine attached to 24 to 26 soft rays, while the [[pelvic fin]] has one spine attached to 21 or 22 soft rays.<ref name = "Lin1999">{{cite journal | last = Lin | first = Pai-Lei | author2 = Shao, Kwang-Tsao | title = A Review of the Carangid Fishes (Family Carangidae) From Taiwan with Descriptions of Four New Records | journal = Zoological Studies | volume = 38 | issue = 1 | pages = 33–68 | date = 1999 | url = http://cat.inist.fr/?aModele=afficheN&cpsidt=10055944 | access-date = 2008-10-31 | archive-date = 2012-02-29 | archive-url = https://web.archive.org/web/20120229173915/http://cat.inist.fr/?aModele=afficheN&cpsidt=10055944 }}</ref> The [[lateral line]] has a very slight anterior arch, with the intersection of the straight and curved sections between the 15th and 19th soft rays of the dorsal fin. The curved section contains 96 to 106 [[scale (zoology)|scales]], while the straight section contains 20 to 30 scales and 21 to 28 [[scute]]s.<ref name = "Lin1999"/> The breast is scaleless ventrally until the origin of pelvic fins, often with a small patch of prepelvic scales. Laterally, this naked area of the breast is separated from the naked base of the [[pectoral fin]]s by a moderate band of scales. The lips are notably fleshy in adults, with both jaws containing narrow bands of [[Ichthyology terms#V|villiform]] teeth which become [[obsolescent]] with age. There are 28 to 32 [[gill raker]]s in total and 24 [[vertebrae]].<ref name = "FAO"/>

The island trevally is a pale blue-green above, becoming more silvery below, with adults having several quite large, [[Ellipse|elliptical]], yellow to brassy spots scattered on their bodies close to the midline. Nine 9 or 10 dark vertical bars may be on the body from the head to the [[caudal peduncle]]. The soft dorsal, anal, and [[caudal fin]]s are a pale brownish- to brilliant-blue, with all other fins being pale green to [[hyaline]] in colour.<ref name = "Gunn">{{cite journal | doi = 10.3853/j.0812-7387.12.1990.92 | last = Gunn | first = John S. | title = A revision of selected genera of the family Carangidae (Pisces) from Australian waters | journal = Records of the Australian Museum Supplement| volume = 12 | pages =1–78 | date = 1990 | doi-access = free }}</ref>

==Distribution and habitat== [[File:Island trevally solomons.jpg|thumb|Anglers catch of island trevally]] The island trevally is distributed throughout the [[Shore|offshore]] waters of the tropical and subtropical regions of the [[Indian Ocean|Indian]] and [[Pacific Ocean]]s. In the Indian Ocean, it ranges from [[Mozambique]] on the east coast of Africa north to the [[Gulf of Aden]], but has not been recorded further north until [[India]] and [[Sri Lanka]].<ref name = "fishbase"/> Its range extends throughout [[Southeast Asia]], [[Indonesia]], and [[northern Australia]] in the eastern Indian Ocean. In the Pacific, the species has been recorded from [[Taiwan]], [[Japan]], and [[Hawaii]] to the [[Revillagigedo Islands]] off [[Mexico]] in the eastern Pacific, as well as many Pacific islands.<ref name = "fishbase"/>

As the species common name partly suggests, the island trevally very rarely is found on the [[continental shelves]], instead living around offshore islands formed by [[volcanism|volcanic activity]] or isolated slivers of continental material remaining from continental drifting. These islands are often quite large, and have most of the geographical features of the continental environment, including [[beaches]], [[reef]]s, [[lagoon]]s, and even [[estuaries]]. The island trevally is known from all of these habitats, as well as slightly deeper seaward reefs up to 50 m deep.<ref>{{cite journal | last = Robertson | first = D.R. |author2=G.R. Allen | title = Zoogeography of the shorefish fauna of Clipperton Atoll | journal = Coral Reefs | volume = 15 | issue = 2 | pages = 121–131 | date = 1996 | doi=10.1007/bf01771902| bibcode = 1996CorRe..15..121R | s2cid = 41906452 }}</ref> In Hawaii, the species is less frequently found inside protected bays, and more often slightly further offshore presumably due to competition with other species.<ref name = "Hawaiijack">{{cite journal | last = Meyer | first = Carl G. |author2=Kim N. Holland |author3=Bradley M. Wetherbee |author4=Christopher G. Lowe | title = Diet, resource partitioning and gear vulnerability of Hawaiian jacks captured in fishing tournaments | journal = Fisheries Research | volume = 53 | issue = 2 | pages = 105–113 | date = 2001 | doi = 10.1016/S0165-7836(00)00285-X | bibcode = 2001FishR..53..105M }}</ref> The island trevally is one of a number of carangid species known to be attracted to man-made fish-attracting devices, which are installed to aggregate fish for anglers.<ref>{{cite journal | last = Gaertner | first = J.C. |author2=M. Taquet |author3=L. Dagorn |author4=B. Mérigot |author5=R. Aumeeruddy |author6=G. Sancho |author7=D. Itano | title = Visual censuses around drifting fish aggregating devices (FADs): a new approach for assessing the diversity of fish in open-ocean waters | journal = Marine Ecology Progress Series | volume = 366 | issue = 3 | pages = 175–186 | date = 2008 | doi = 10.3354/meps07554 | bibcode = 2008MEPS..366..175G | doi-access = free }}</ref>

==Biology and fishery== The island trevally moves both as a solitary individual or in small [[Shoaling and schooling|schools]] through its habitat, with the species often accounting for large proportions of an areas immediate [[biomass]] when moving in schools.<ref>{{cite journal | last = Brock | first = R.E. | title = Community Structure of Fishand Macrobenthosat Selected Sites Fronting Sand Island, O'Ahu, Hawaii, in Relation to the Sand Island Ocean Outfall, Year 9 - 1998 | journal = Water Resources Research Centre Project Report | volume = PR-99-07 | pages = 1–49 | date = 1998 | url = http://browser.grik.net/browser.php/www.epa.gov/region09/water/npdes/pdf/sand-island/SI-application-attG-4.pdf | access-date = 2008-10-28}} {{Dead link|date=November 2010|bot=H3llBot}}</ref> The species' diet consists of small fish species and [[crustacean]]s, with studies on their exact diet composition finding these fish take different species and different ratios of prey throughout their range. A study conducted in [[New Caledonia]] found the species consumed 98% fish, with only 1% [[crab]]s and [[shrimp]],<ref>{{cite journal | last = Kulbicki | first = Michel |author2=Yves-Marie Bozec |author3=Pierre Labrosse |author4=Yves Letourneur |author5=Gérard Mou-Tham |author6=Laurent Wantiez | title = Diet composition of carnivorous fishes from coral reef lagoons of New Caledonia | journal = Aquatic Living Resources | volume = 18 | issue = 3 | pages = 231–250 | date = 2005 | doi = 10.1051/alr:2005029 | s2cid = 54954245 | doi-access = free }}</ref> while a large study in Hawaii found it took 64.7% crustaceans including crabs, shrimp, and [[stomatopod]]s, while taking only 32.3% fish consisting of [[gobies]] and benthic fishes of the order [[Scorpaeniformes]], as well as 2% [[cephalopod]]s.<ref name = "Hawaiijack"/> In this setting, the major carangid species in the region apparently alter their diets to reduce [[interspecific competition]], but change this partitioning elsewhere in their range where they co-occur.<ref name = "Hawaiijack"/> [[Reproduction]] and growth are poorly studied in the species, with only a general estimate of spawning timing of March in the [[Solomon Island]]s.<ref>{{cite journal | last = Rhodes | first = K.L. | title = Solomon Islands Spawning Aggregation Monitoring Training Workshop Report Gizo, Western Province, Solomon Islands 13-21 March 2004 | journal = TNC Pacific Island Countries Report | volume = 2 | issue = 4 | pages = 1–15 | publisher = The Nature Conservancy | date = 2004 | url = http://pdf.usaid.gov/pdf_docs/PNADI933.pdf | archive-url = https://web.archive.org/web/20110522071337/http://pdf.usaid.gov/pdf_docs/PNADI933.pdf | archive-date = May 22, 2011 | access-date = 2008-10-28}}</ref>

The island trevally is of moderate importance to [[fisheries]] throughout its range, often taken by hook and line, [[trawl]]s, and various types of artisanal gear.<ref name = "FAO"/> The species is generally only caught as bycatch, with catch numbers often very small in comparison to the target species of the fishery.<ref>{{cite journal | last = Hardman | first = E.R. | author2 = F.E.I. Blais | author3 = M.S. Desiré | author4 = J.S.J. Raffin | author5 = S. Perrine | author6 = R.M. Chinien-Chetty | author7 = S. Meunier | title = Annual Report on the Status of the Artisanal Seine Net Fishery of Rodrigues 2006 | journal = Shoals Rodrigues, Pointe Monier, Rodrigues | pages = 1–67 | date = 2006 | url = http://www.ncl.ac.uk/tcmweb/tmr/fisheries_2006.pdf | access-date = 2008-10-29 | archive-url = https://web.archive.org/web/20160303183327/http://www.ncl.ac.uk/tcmweb/tmr/fisheries_2006.pdf | archive-date = 2016-03-03 }}</ref> Throughout most of its range, catch statistics are not kept. The species is marketed fresh, dry, or [[salting (food)|salted]], and is considered a good [[table fish]].<ref name = "fishbase"/>

==See also== * [[Blue trevally]]

==References== {{Reflist|2}}

==External links== *[http://www.fishbase.org/Summary/SpeciesSummary.php?id=1909 Island trevally at Fishbase] *[http://www.amonline.net.au/fishes/fishfacts/fish/corthogram.htm Australian Museum Online fact sheet] *[http://www.bishopmuseum.org/research/natsci/fish/images/yellowulua.html Bishop Museum Online] {{Webarchive|url=https://web.archive.org/web/20080621111126/http://www.bishopmuseum.org/research/natsci/fish/images/yellowulua.html |date=2008-06-21 }} * {{SealifePhotos|218393}}

[[Category:Caranginae]] [[Category:Marine fish of East Africa]] [[Category:Fish of the Pacific Ocean]] [[Category:Fish of Hawaii]] [[Category:Fish described in 1881|island trevally]] [[Category:Taxa named by David Starr Jordan]] [[Category:Taxa named by Charles Henry Gilbert]]