Herring scad

{{short description|Species of fish}} {{Speciesbox | image = Herring scad.JPG | status = LC | status_system = IUCN3.1 | status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Collen, B. |author2=Richman, N. |author3=Beresford, A. |author4=Chenery, A. |author5=Ram, M. |collaboration=Sampled Red List Index Coordinating Team |date=2010 |title=''Alepes vari'' |volume=2010 |article-number=e.T155134A4725434 |doi=10.2305/IUCN.UK.2010-4.RLTS.T155134A4725434.en |access-date=19 November 2021}}</ref> | taxon = Alepes vari | authority = (G. Cuvier, 1833) | synonyms = *''Caranx vari'', G. Cuvier, 1833 *''Selar macrurus'', Bleeker, 1851 *''Caranx macrurus'', (Bleeker, 1851) *''Alepes macrurus'', (Bleeker, 1851) *''Alepes glabra'', Fowler, 1904 | range_map = Alepes vari distribution.PNG | range_map_caption = Approximate range of the herring scad }}

The '''herring scad''' ('''''Alepes vari''''') (also known as the '''duskyfin crevalle''' and '''trevally scad'''), is a common species of tropical marine fish in the jack family Carangidae. The species inhabits the surface waters of coastal regions throughout the Indo-West Pacific region, feeding on a variety of crustaceans and small fishes. It is the largest fish of the scad genus ''Alepes'', growing to a recorded length of 56 cm. The herring scad is identified among the genus ''Alepes'' by its more numerous and smaller scutes and the number of gill rakers on the first arch. It is of minor importance to fisheries throughout its range.

==Taxonomy and naming== The herring scad is one of five extant species in the scad genus ''Alepes'', a group of fish in the jack family, Carangidae. The Carangidae are part of the 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=2019-11-23 |archive-date=2019-04-08 |archive-url=https://web.archive.org/web/20190408194051/https://sites.google.com/site/fotw5th/ }}</ref>

The species was first scientifically described by the French naturalist Georges Cuvier in 1833 from a specimen now lost to science.<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 | year = 2007 | location = Sydney | page = 1150 | isbn =978-0-643-09334-8 }}</ref> He named the species ''Caranx vari'', believing the fish was closely affiliated with the large jacks of that genus. The species was later transferred to the scad genus ''Alepes'' by Gushiken in 1983, and a specimen from Puducherry, India was designated to be the lectotype the following year by Smith-Vaniz.<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 | url = http://cat.inist.fr/?aModele=afficheN&cpsidt=10055944 | date = 2 April 1999 | access-date = 29 January 2008 | archive-date = 29 February 2012 | archive-url = https://web.archive.org/web/20120229173915/http://cat.inist.fr/?aModele=afficheN&cpsidt=10055944 }}</ref> The species was redescribed and renamed twice after Cuvier's description, first by Pieter Bleeker as ''Selar macrurus'' and then by Henry Fowler as ''Alepes glabra'', both of which are junior synonyms discarded under ICZN rules. Although commonly called the 'herring scad', the names duskyfin crevalle, trevally scad and, incorrectly, blackfin scad (''A. melanoptera'') are applied to the species.<ref>{{cite web |last=Zipcode Zoo |title=''Alepes vari'' |publisher=BayScience Foundation, Inc |url=http://zipcodezoo.com/animals/a/alepes_vari/ |access-date=2008-01-28 |archive-url=https://web.archive.org/web/20090727111418/http://zipcodezoo.com/Animals/A/Alepes_vari/ |archive-date=2009-07-27 }}</ref>

==Description== thumb|200px|left|The herring scad is an ovate shape, commonly blue green above and silver belowThe herring scad has a body profile very similar to other members of the genus ''Alepes'', having a strongly compressed, ovate body. The ventral and dorsal profiles of the fish are almost evenly convex, joined anteriorally by a pointed snout. There are two separate dorsal fins, the first containing 8 spines while the second has a single spine followed by 24 to 27 soft rays. The anal fin consists of two anteriorally detached small spines followed by a single spine connected to 20 to 23 soft rays.<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 lateral line is strongly arched anteriorally with the junction of the curved and straight sections located the origin of second dorsal to the third soft ray. The curved section contains 42 to 50 scales and 0 to 2 scutes, while the straight section has 0 to 7 scales and 48 to 69 scutes.<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 | year = 1990 | doi-access = free }}</ref> There is a well-developed adipose eyelid on the posterior half of the eye. The jaws hold a single row of numerous comb like teeth. There are 32 to 38 gill rakers and a total of 24 vertebrae. The herring scad is by far the largest species in ''Alepes'', growing to 56 cm in total length, although is more commonly encountered at below 30 cm.<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 | year = 2001 | location = Rome | page = 2684 | url = ftp://ftp.fao.org/docrep/fao/009/y4160e/y4160e00.pdf | isbn = 92-5-104587-9 }}</ref>

The species is an ash blue above, fading to a silvery white below, with a diffuse dusky blotch on margin of operculum. The fins are dusky with the exception of the spinous dorsal fin which is pale to dark dusky. The amount of dark pigment in the fins is sexually dimorphic, with males developing darker spinous dorsal fin, lobes of soft dorsal and anal fins, and pelvic fins than females.<ref name = "FAO"/>

==Distribution and habitat== The herring scad is distributed throughout tropical to subtropical regions of the Indo-West Pacific oceans. The species has been recorded from the Red Sea, eastward to Sri Lanka, India, Southeast Asia, China, Indonesia, the Philippines, New Guinea, and as far north as Taiwan<ref name = "Lin1999"/> and as far south as northern Australia.<ref name = "fishbase">{{FishBase species | genus = Alepes | species = vari | year = 2008 | month = January}}</ref> The herring scad is most commonly found in shallow coastal regions where it inhabits the surface layers of the ocean over a variety of substrates.<ref name = "FAO"/>

==Biology and fishery== [[File:Parasite140007-fig2 Philometra austropacifica Moravec & Justine, 2014 (Nematoda, Philometridae).tif|thumb|left|200 px|''Philometra austropacifica'' (Nematoda, Philometridae), a parasite of the ovary of the herring scad. SEM.]]

The herring scad is a carnivorous species, known to consume a variety of crustaceans including shrimps, copepods and decapods as well as other small fishes. It is one of a number of pelagic fish from the Red Sea found to have high numbers of luminescent bacteria in its gut, living symbiotically with the fish as part of the gut flora.<ref>{{cite journal | last = Makemson | first = John C. |author2=Gregorio V. Hermosa Jr | title = Luminous bacteria cultured from fish guts in the Gulf of Oman | journal = Luminescence | volume = 14 | issue = 3 | pages = 161–168 | publisher = John Wiley & Sons, Ltd. | year = 1999 | url = http://www3.interscience.wiley.com/cgi-bin/abstract/62500642/ABSTRACT | archive-url = https://archive.today/20121217200432/http://www3.interscience.wiley.com/cgi-bin/abstract/62500642/ABSTRACT | archive-date = 2012-12-17 | access-date = 2008-01-29 | doi = 10.1002/(SICI)1522-7243(199905/06)14:3<161::AID-BIO538>3.0.CO;2-A | pmid = 10423577| url-access = subscription }}</ref>

Parasites of the herring scad include the philometrid nematode ''Philometra austropacifica'', which lives inside the ovary of the females.<ref name="MoravecJustine2014">{{cite journal|last1=Moravec|first1=František|last2=Justine|first2=Jean-Lou|title=Philometrids (Nematoda: Philometridae) in carangid and serranid fishes off New Caledonia, including three new species|journal=Parasite|volume=21|year=2014|page=21|issn=1776-1042|doi=10.1051/parasite/2014022|pmid=24836940|pmc=4023622}} {{open access}}</ref>

The species is of little importance to fisheries, taken occasionally on hook and line gear.<ref name = "FAO"/>

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

==External links== *[http://www.fishbase.org/Summary/SpeciesSummary.php?id=1891 Herring scad at Fishbase] *[https://web.archive.org/web/20120210054917/http://zipcodezoo.com/Animals/A/Alepes_vari.asp Zipcode Zoo page] * {{sealifephotos|218383}}

{{DEFAULTSORT:Herring Scad}} Category:Alepes Category:Fish described in 1833 Category:Taxa named by Georges Cuvier