Blue runner

{{Short description|Species of fish}} {{Use dmy dates|date=September 2020}} {{Speciesbox | image = Blue runner (Caranx crysos).jpg | status = LC | status_system = IUCN3.1 | status_ref =<ref name="iucn status 19 November 2021">{{cite iucn |author=Herdson, D. |date=2010 |title=''Caranx crysos'' |volume=2010 |article-number=e.T154807A4637970 |doi=10.2305/IUCN.UK.2010-4.RLTS.T154807A4637970.en |access-date=19 November 2021}}</ref> | taxon = Caranx crysos | authority = (Mitchill, 1815) | range_map = Caranx crysos distribution.png | range_map_caption = Approximate range of the blue runner | synonyms = *''Scomber crysos'' Mitchill, 1815 *''Carangoides crysos'' (Mitchill, 1815) *''Paratractus crysos'' (Mitchill, 1815) *''Caranx fusus'' Geoffroy Saint-Hilaire, 1817 *''Carangoides fusus'' (Geoffroy Saint-Hilaire, 1817) *''Caranx pisquetus'' Cuvier, 1833 *''Trachurus squamosus'' Gronow, 1854 }}

The '''blue runner''' ('''''Caranx crysos'''''), also known as the '''bluestripe jack''', '''Egyptian scad''', '''hardtail jack''', or '''hardnose''', is a common species of moderately large marine fish classified in the jack family, Carangidae. The blue runner is distributed across the Atlantic Ocean, ranging from Brazil to Canada in the western Atlantic and from Angola to Great Britain including the Mediterranean in the east Atlantic. The blue runner is distinguished from similar species by several morphological features, including the extent of the upper jaw, gill raker count, and lateral line scale counts. The blue runner is known to reach a maximum length of 70 cm and 5.05 kg in weight, but is much more common below 35 cm. The species inhabits both inshore and offshore environments, predominantly over reefs, but it is known to congregate around large, man-made, offshore structures such as oil platforms. Juveniles tend to inhabit shallower reef and lagoon waters, before moving to deeper waters as adults.

The blue runner is a schooling, predatory fish, predominantly taking fish in inshore environments, as well as various crustaceans and other invertebrates. Fish living offshore feed nearly exclusively on zooplankton. The species reaches sexual maturity between 225 and 280 mm across its range, with spawning occurring offshore year-round, although this peaks during the warmer months. Larvae and juveniles live pelagically, often under sargassum mats or jellyfish until they move inshore. The blue runner is of high importance to fisheries, with an annual catch between 6000 and 7000 tonnes taken from the Americas in the last five years. The species is also a light-tackle gamefish, taking baits, lures, and flies, but is often used as bait itself, being a mediocre table fish. Some suggest that the eastern Pacific species ''Caranx caballus'', the green jack, may be conspecific with ''C. crysos'', although this currently remains unresolved.

==Taxonomy and naming== The blue runner is classified within the genus ''Caranx'', one of a number of groups known as the jacks or trevallies. ''Caranx'' itself is part of the larger jack and horse mackerel family Carangidae, 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=25 November 2019 |archive-date=8 April 2019 |archive-url=https://web.archive.org/web/20190408194051/https://sites.google.com/site/fotw5th/ }}</ref>

The species was first scientifically described by American ichthyologist Samuel L. Mitchill in 1815, based on a specimen taken from the waters of New York Bay, USA, which was designated to be the holotype.<ref name = "mitch">{{cite journal | last = Mitchill | first = S.L. | title = The fishes of New York described and arranged | journal=Transactions of the Literary and Philosophical Society of New York | volume = 1 | pages = 355–492 | publisher=Van Winkle and Wiley | year = 1815 }}</ref> He named the species ''Scomber crysos'' and suggested a common name of 'yellow mackerel', with the specific epithet reflecting this, meaning "gold" in Greek.<ref name = "mitch"/> The taxon has been variably placed in either ''Caranx'', ''Carangoides'' or ''Paratractus'', but is now considered valid as ''Caranx crysos''.<ref name = "fishbase">{{FishBase | genus = Caranx | species = crysos | year = 2009 | month = May}}</ref> The species has been independently redescribed three times, first as ''Caranx fusus'', which is still incorrectly used by some authors<ref name = "Carrib">{{cite book|last= Munro|first= J. L.|title= Caribbean Coral Reef Fishery Resources|year= 1983|orig-date= 1974|type= A second edition of ''The biology, ecology, exploitation, and management of Caribbean reef fishes'' : scientific report of the ODA/UWI Fisheries Ecology Research Project, 1969-1973, University of the West Indies, Jamaica.|publisher= International Center for Living Aquatic Resources Management|location= Manila|isbn= 971-10-2201-X|pages= [https://archive.org/details/caribbeancoralre0000unse/page/82 82–94]|chapter= The Biology, Ecology and Bionomics of the Jacks, Carangidae|chapter-url= https://archive.org/details/caribbeancoralre0000unse/page/82}}</ref> (occasionally as ''Carangoides fusus''), and later as ''Caranx pisquetus'' and ''Trachurus squamosus''. These names are considered invalid junior synonyms under ICZN rules. The species has many common names, with the most common being blue runner. Other, less commonly used names include bluestripe jack, Egyptian scad, hardtail jack, hardnose, white-back cavalli, yellow-tail cavalli, ands a variety of broad names such as mackerel, runner, and crevalle.<ref name = "fishbase"/><ref>{{cite book | last = Jennings | first = G.H. | title = Sea fishes of the Caribbean Sea & Gulf of Mexico: Guyana to Florida: a classified taxonomic checklist of recorded species from the West Central Atlantic area | publisher=Calypso Publications | year = 1999 | page = 149 | isbn = 978-0-906301-88-3 }}</ref>

The blue runner may be conspecific with the eastern Pacific species ''Caranx caballus'' (green jack), although no specific studies have been undertaken to examine this relationship.<ref name = "nichols1920">{{cite journal | last = Nichols | first = J.T. | title = On ''Caranx crysos'', Etc | journal=Copeia | volume = 81| pages = 29–30 | year = 1920 | jstor = 1435930 | issue = 81 | publisher=American Society of Ichthyologists and Herpetologists | doi=10.2307/1435929}}</ref><ref name = "FAOPCO">{{cite book | last = Fischer | first = W. |author2=Krupp F. |author3=Schneider W. |author4=Sommer C. |author5=Carpenter K.E. |author6=Niem V.H. | title = Guía FAO para la identificación de especies para los fines de la pesca. Pacífico centro-oriental. Volumen II. Vertebrados – Parte 1. | publisher=FAO | year = 1995 | location = Rome | page = 953 | url = http://www.fao.org/fishery/sidp/3,1/en#Ecp | isbn = 92-5-303409-2 }}</ref> Both species were included in a recent genetic analysis of the entire family Carangidae, with results showing both species are very closely related, although the authors did not comment on genetic distance between the two.<ref>{{cite journal | last = Reed | first = David L. |author2=Carpenter, Kent E. |author3=deGravelle, Martin J. | title = Molecular systematics of the Jacks (Perciformes: Carangidae) based on mitochondrial cytochrome b sequences using parsimony, likelihood, and Bayesian approaches | journal=Molecular Phylogenetics and Evolution | volume = 23 | issue = 3 | pages = 513–524 | year = 2002 | doi = 10.1016/S1055-7903(02)00036-2 | pmid = 12099802 | bibcode = 2002MolPE..23..513R }}</ref>

==Description== 240 px|thumb|left|A small blue runner in profile The blue runner is moderately large in size, growing to a maximum confirmed length of 70 cm and 5.05 kg in weight, but is more common at lengths less than 35 cm.<ref name = "fishbase"/> The blue runner is morphologically similar to a number of other carangids, having an elongated, moderately compressed body with dorsal and ventral profiles of approximately equal convexity and a slightly pointed snout.<ref name = "FAO">{{cite book | editor-last = Carpenter | editor-first = K.E. | title = The living marine resources of the Western Central Atlantic. Volume 3: Bony fishes part 2 (Opistognathidae to Molidae), sea turtles and marine mammals |series= FAO Species Identification Guide for Fishery Purposes and American Society of Ichthyologists and Herpetologists Special Publication No. 5 | publisher=FAO | year = 2002 | location = Rome | page = 1438 | url = ftp://ftp.fao.org/docrep/fao/009/y4162e/y4162e00.pdf | isbn = 92-5-104827-4 }}</ref> The posterior section of the eye is covered by a moderately well developed adipose eyelid, and the posterior extremity of the jaw is vertically under the center of the eye.<ref name = "Fishid">{{cite book | last = Fischer | first = W |author2=Bianchi, G. |author3=Scott, W.B. | title = FAO Species Identification Sheets for Fishery Purposes: Eastern Central Atlantic Vol 1 | publisher=Food and Agricultural Organization of the United Nations | year = 1981 | location = Ottawa | url = http://www.fao.org/fishery/sidp/3,1/en#Eca }}</ref> The dorsal fin is in two parts, the first consisting of eight spines and the second of one spine followed by 22 to 25 soft rays. The anal fin consists of two anteriorly detached spines followed by one spine and 19 to 21 soft rays.<ref name = "FAO"/> The pectoral fins become more falcated with age,<ref name = "nichols1920"/> having 21 to 23 rays, and are slightly longer than the head.<ref name = "Mexico">{{cite book | last = McEachran | first = J.D. |author2=J.D. Fechhelm | title = Fishes of the Gulf of Mexico: Scorpaeniformes to tetraodontiformes | publisher=University of Texas Press | year = 2005 | location = Austin, TX | page = 1014 | isbn = 978-0-292-70634-7}}</ref> The lateral line has a pronounced but short anterior arch, with the curved section intersecting the straight section below the spine of the second dorsal fin. The straight section contains from none up to seven scales followed by 46 to 56 very strong scutes, with bilateral keels present on the caudal peduncle. From 86 to 98 scales and scutes are over the entire lateral line.<ref>{{cite journal | last = Berry | first = F.H. | title = Scale and scute development of the carangid fish ''Caranx crysos'' (Mitchill) | journal=Quarterly Journal of the Florida Academy of Sciences | volume = 23 | pages = 59–66 | year = 1960 }}</ref> The chest is completely scaled. The upper jaw contains an irregular series of outer canines with an inner band of small, regularly spaced teeth, while the lower jaw contains a single band of small teeth.<ref name = "Fishid"/> The species has 35 to 42 gill rakers in total, 10 to 14 on the upper limb and 25 to 28 on the lower limb, with this the only feature that differs between ''C. crysos'' and ''C. caballus''. Twenty-five vertebrae are present.<ref name = "FAO"/>

The blue runner's colour varies from bluish green to olive green dorsally, becoming silvery grey to brassy below. Juveniles often have seven dark, vertical bands on their bodies. Fin colour also varies, with all fins ranging from to dusky or hyaline to olive green. The species also has a dusky spot, which may not be distinct on the upper operculum.<ref name = "Fishid"/><ref name = "Mexico"/>

==Distribution== The blue runner is extensively distributed throughout the tropical and temperate waters of the Atlantic Ocean, ranging widely along both the eastern American coastline and the western African and European coastlines.<ref name = "fishbase"/> In the western Atlantic, the species' southernmost record comes from Maceio, Brazil,<ref name = "FAO"/> with the species ranging north along the Central American coastline, and throughout the Caribbean and the numerous archipelagos throughout.<ref name = "Mexico"/> From the Gulf of Mexico, its distribution extends north along the U.S. coast and as far north as Nova Scotia in Canada, also taking in several north-west Atlantic islands.<ref name = "fishbase"/> The blue runner is also present on several central Atlantic islands, making its distribution Atlantic-wide.{{Citation needed|date=July 2021}}

In the eastern Atlantic, the southernmost record is from Angola, with the blue runner distributed extensively along the west African coast north to Morocco and into the Mediterranean Sea.<ref name = "Fishid"/> The blue runner is found throughout the Mediterranean, having been recorded from nearly all the countries on its shores.<ref name = "fishbase"/> The species is rarely found north of Portugal in the north-east Atlantic, although records do exist of isolated catches from Madeira Island<ref>{{cite journal | last = Wirtz | first = P. |author2=R. Fricke|author3=M.J. Biscoito | title = The coastal fishes of Madeira Island – new records and an annotated check-list | journal=Zootaxa | volume = 1715 | pages = 1–26 | year = 2008 | issn = 1175-5326 | doi = 10.11646/zootaxa.1715.1.1 }}</ref> and Galicia, Spain.<ref>{{cite journal| last = Banon Diaz | first = R. |author2=J.M. Casas Sanchez | title = First record of ''Caranx crysos'' (Mitchill, 1815), in Galician waters | journal=Boletin del Instituto Espanol de Oceanografia | volume = 31 | issue = 1–2 | pages = 79–81 | year = 1998 | issn = 0074-0195 }}</ref> The furthest north it has been reported is southern Great Britain, where two specimens were taken in 1992 and 1993.<ref>{{cite journal | last = Swaby | first = S.E. |author2=G.W. Potts|author3=J. Lees | title = The first records of the blue runner ''Caranx crysos'' (Pisces: Carangidae) in British waters | journal=Journal of the Marine Biological Association of the United Kingdom | volume = 76 | issue = 2 | pages = 543–544 | year = 1996 | issn = 0025-3154 | doi = 10.1017/S0025315400030745 | bibcode = 1996JMBUK..76..543S | s2cid = 84294903 }}</ref> A trend has been seen of having this and other tropical species found further north more often, with publications indicating the blue runner has recently established stable populations in the Canary Islands, where it had been rarely sighted. Some authors have attributed this northward migration to rising sea surface temperatures, possibly the result of climate change.<ref>{{cite journal | last = Brito | first = A. |author2=J.M. Falcon|author3=R. Herrera | title = Sobre la tropicalizacion reciente de la ictiofauna litoral de las islas Canarias y su relacion con cambios ambientales y actividades antropicas | journal=Vieraea | volume = 33 | pages = 515–525 | year = 2005 | issn = 0210-945X }}</ref>

==Habitat== thumb|240 px|A shoal of blue runner under an oil platform in the Gulf of Mexico The blue runner is primarily an inshore fish throughout most of its range, but it is known to live on reefs in water depths greater than 100 m.<ref name = "Fishid"/> Throughout much of its Central American range, it is quite rare inshore, instead more commonly sighted on the outer reefs.<ref name = "FAO"/> The blue runner is primarily a semipelagic fish, inhabiting both inshore reefs and the outer shelf edges, sill reefs, and upper slopes of the deep reef.<ref name = "Carrib"/> Those individuals on shallower reefs often move between reef patches over large sand expanses. Juvenile fish are also known to inhabit the shallow waters of inshore lagoons, taking refuge around mangroves<ref name = "FAO"/> or in seagrass amongst coral reef patches.<ref>{{cite journal | last = Alvarez-Guillen | first = H. |author2=M.L.C. Garcia-Abad |author3=M. Tapia Garcia |author4=G.J. Villalobos Zapata |author5=A. Yanez-Arancibia | title = Ichthyoecological survey in the sea grass zone of the reef lagoon of Puerto Morelos Quintana Roo Mexico Summer 1984 | journal=Anales del Instituto de Ciencias del Mar y Limnologia Universidad Nacional Autonoma de Mexico | volume = 13 | issue = 3 | pages = 317–336 | year = 1986 | issn = 0185-3287 }}</ref> Fishermen have also taken the species in the Mississippi Delta, indicating it can tolerate lower salinities in almost estuarine environments.<ref name = "goodwin">{{cite journal | last = Goodwin | first = J.M. |author2=A.G. Johnson | title = Age growth and mortality of blue runner ''Caranx crysos'' from the northern Gulf of Mexico | journal=Northeast Gulf Science | volume = 8 | issue = 2 | pages = 107–114 | year = 1986 | issn = 0148-9836 | doi = 10.18785/negs.0802.02 | doi-access = free }}</ref>

Blue runner are easily attracted to any large underwater or floating device, either natural or man made. Several studies have shown the species congregates around floating, buoy-like fish aggregating devices, both in shallower waters and in extremely deep (2500 m) waters, indicating the species may move around pelagically.<ref name = "antilles">{{cite journal | last = Doray | first = M. |author2=E. Josse |author3=P. Gervain |author4=L. Reynal |author5=J. Chantrel | title = Joint use of echosounding, fishing and video techniques to assess the structure of fish aggregations around moored Fish Aggregating Devices in Martinique (Lesser Antilles) | journal=Aquatic Living Resources | volume = 20 | issue = 4 | pages = 357–366 | year = 2007 | doi = 10.1051/alr:2008004 | s2cid = 17177578 |url=http://hal.univ-brest.fr/hal-00636918/document | doi-access = free }}</ref> In these situations, blue runner always form small aggregations at the water surface, while other larger species tend to congregate slightly deeper.<ref name = "antilles"/> A number of investigations around oil and gas platforms in the Gulf of Mexico have found blue runner congregate in large numbers around these in the warmer months, where they modify their feeding behavior to take advantage of the structure.<ref name = "gasoil">{{cite journal | last = Stanley | first = D.R. |author2=B.A. Scarborough | title = Seasonal and spatial variation in the biomass and size frequency distribution of fish associated with oil and gas platforms in the northern Gulf of Mexico | journal=Fisheries, Reefs, and Offshore Development | volume = 36 | pages = 123–153 | year = 2003 | issn = 0892-2284 }}</ref> Purpose-built artificial reefs<ref>{{cite journal | last = Brotto | first = D.S. |author2=W. Krohling |author3=S. Brum |author4=I.R. Zalmon | title = Usage patterns of an artificial reef by the fish community on the northern coast of Rio de Janeiro – Brazil | journal=Journal of Coastal Research | volume = 3 | issue = Special Issue 39 | pages = 1276–1280 | year = 2006 | issn = 0749-0208 }}</ref> and marine aquaculture cage structures are also known to attract the species, with the former having the added benefit of dispersing wayward food scraps.<ref>{{cite journal| last = Vega Fernandez | first = T. |author2=G. D'Anna |author3=F. Badalamenti |author4=C. Pipitone |author5=M. Coppola |author6=G. Rivas |author7=A. Modica | title = Fish fauna associated to an off-shore aquaculture system in the Gulf of Castellammare (NW Sicily) | journal=Biologia Marina Mediterranea | volume = 10 | issue = 2 (Supp.) | pages = 755–759 | year = 2003 | issn = 1123-4245 }}</ref>

==Biology== The blue runner normally moves either in small schools or as solitary individuals,<ref name = "FAO"/> although large aggregations of up to 10,000 individuals are known in unusual circumstances.<ref name = "gasoil"/> Throughout some parts of its range, it is one of the most abundant species; for example, statistics from Santa Catarina Island indicate it is the third-most abundant species.<ref name="Martins 2008 413–423">{{cite journal | last = Martins | first = R.S. | author2 = M.J.A. Perez | title = Artisanal Fish-Trap Fishery Around Santa Catarina Island During Spring/Summer: Characteristics, Species Interactions and the Influence of the Winds on the Catches | journal = Boletim do Instituto de Pesca | volume = 34 | issue = 3 | pages = 413–423 | year = 2008 | url = https://institutodepesca.org/index.php/bip/article/download/810/793/2926 }}</ref> Their biology, particularly reproductive and growth biology, has been quite extensively studied in the blue runner due to this high abundance in the Atlantic, and its importance to fisheries and the ecology of its environment.{{Citation needed|date=July 2021}}

===Diet and feeding=== The blue runner is a fast-swimming predator, which primarily takes small, benthic fishes as prey in inshore waters.<ref name = "FAO"/> Studies on the species' diet on both side of the Atlantic have shown similar results. A Puerto Rican study found the species supplements its fish-dominated diet with crabs, shrimp, copepods, and other small crustaceans.<ref>{{cite journal | last = Randall | first = J.E. | title = Food habits of reef fishes of the West Indies | journal=Studies in Tropical Oceanography | volume = 5 | pages = 665–847 | year = 1967 | issn = 0081-8720 }}</ref> More detailed research in Cape Verde found as well as fish, blue runner take shrimp, prawns, lobsters, jellyfish, and other small invertebrates.<ref>{{cite book | last = da Silva Monteiro | first = V.M. | title = Peixes de Cabo Verde | publisher=Ministério do Mar, Gabinete do Secretário de Estado da Cultura. M2- Artes Gráficas, Lda | year = 1998 | location = Lisbon | page = 179 }}</ref> The diet of juveniles is more zooplankton-dominated, with young fish predominantly taking cyclopoid and calanoid copepods, and gradually moving to a more fish-based diet.<ref>{{cite journal | last = Mirto | first = S. |author2=M. Bellavia|author3=T. La Rosa | title = Primi dati sulle abitudini alimentari di giovanili di ''Caranx crysos'' nel Golfo di Castellammare (Sicilia nord occidentale) | journal=Biologia Marina Mediterranea | volume = 9 | issue = 1 (Supp.) | pages = 726–728 | year = 2002 | issn = 1123-4245 }}</ref> Adults living offshore or aggregating around oil and gas platforms tend to have less fish in their diet, foraging extensively on larger zooplankton during the summer, with larval decapods and stomatopods, hyperiid amphipods, pteropods, and larval and juvenile fishes also taken.<ref name = "foodoil">{{cite book | last = Keenan | first = S.F. |author2=M.C. Benfield| title = Importance of zooplankton in the diets of Blue Runner (''Caranx crysos'') near offshore petroleum platforms in the Northern Gulf of Mexico|series=OCS Study MMS 2003-029 | publisher=Coastal Fisheries Institute, Louisiana State University. U.S. Dept. of the Interior | year = 2003 | location = New Orleans | page = 129 }}</ref>

Studies around these platforms has found blue runner feed with equal intensity during both day and night, with larger prey such as fish taken preferentially at night, with smaller crustaceans taken during the day.<ref name = "foodoil"/> Blue runner are one of a number of carangids known to forage in small schools alongside actively feeding spinner dolphins (''Stenella longirostris''), taking advantage of any scraps of food left by the feeding mammals, or any organisms displaced while they forage.<ref name = "dolph">{{cite journal | last = Sazima | first = I. |author2=C. Sazima|author3=J.M. da Silva | title = Fishes associated with spinner dolphins at Fernando de Noronha Archipelago, tropical Western Atlantic: an update and overview | journal=Neotropical Ichthyology | volume = 4 | issue = 4 | pages = 451–455 | year = 2006 | url = http://www.scielo.br/pdf/ni/v4n4/a09v4n4.pdf| doi = 10.1590/S1679-62252006000400009 | doi-access = free }}</ref> The species is also known to eat the dolphins' excrement.<ref name = "dolph"/> As well as being important predators, they are also important prey to many larger species, including fishes, birds, and dolphins.<ref name = "fishbase"/><ref>{{cite journal | last = Beltran-Pedrerosde | first = S. |author2=T.M. Araujo Pantoja | title = Feeding habits of ''Sotalia fluviatilis'' in the amazonian estuary | journal=Acta Scientiarum Biological Sciences | volume = 28 | issue = 4 | pages = 389–393 | year = 2006 | url = http://www.periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/viewFile/173/243 | access-date = 22 May 2009}}</ref>

===Reproduction and growth=== thumb|240 px|A school of blue runner in Spain The blue runner reaches sexual maturity at slightly different lengths throughout its range, with all such studies occurring in the west Atlantic. Research in northwest Florida found a length at maturity of 267 mm,<ref name = "goodwin2">{{cite journal | last = Goodwin | first = J.M. |author2=J.H. Finucane | title = Reproductive biology of blue runner ''Caranx crysos'' from the eastern Gulf of Mexico | journal=Northeast Gulf Science | volume = 7 | issue = 2 | pages = 139–146 | year = 1985 | issn = 0148-9836 | doi = 10.18785/negs.0702.02 | doi-access = free }}</ref> a study in Louisiana showed the species reaches sexual maturity at 247–267 mm in females and 225 mm in males, and in Jamaica lengths of 260 mm for males and 280 for females were estimated.<ref name = "shaw">{{cite journal | last = Shaw | first = R.F. |author2=D.L. Drullinger | title = Early-Life-History Profiles, Seasonal Abundance, and Distribution of Four Species of Carangid Larvae off Louisiana, 1982 and 1983 | journal=NOAA Technical Report NMFS | volume = 89 | pages = 1–44 | publisher=US Department of Commerce | year = 1990 }}</ref> Spawning appears to occur offshore year round, although several peaks in spawning activity have been found in different areas through the species range. Peak spawning season in the Gulf of Mexico occurs from June to August, with a secondary peak in spawning during October in northwest Florida.<ref name = "goodwin2"/> Elsewhere, peaks in larval abundance indicate spawning in the warmer summer months.<ref name = "shaw"/> Each female releases between 41,000 and 1,546,000 eggs on average, with larger fish producing more eggs.<ref name = "goodwin2"/> Both the eggs and larvae are pelagic.<ref>{{cite journal | last = Samira | first =S.S | title = Reproductive biology, spermatogenesis and ultrastructure of testes ''Caranx crysos'' (Mitchill, 1815) | journal=Bulletin of the National Institute of Oceanography and Fisheries | volume = 25 | pages = 311–329 | year = 1999 | issn = 1110-0354 }}</ref>

The blue runner's larval stage has been extensively described, with distinguishing features including a slightly shallower body than other larval ''Caranx'' species, and a heavily pigmented head and body.<ref name = "larv">{{cite book | last = Richards | first = William J. | title = Early Stages of Atlantic Fishes: An Identification Guide for the Western Central North Atlantic | publisher=CRC Press | year = 2006 | pages = 2640 pp | isbn = 978-0-8493-1916-7 }}</ref> During this early juvenile stage, there are several dark vertical bars clearly present on the side.<ref name = "larv"/> Larvae and small juveniles remain offshore, living either at depths of around 10 to 20 m,<ref name = "shaw"/> or congregating around floating objects, particularly Sargassum mats and large jellyfish.<ref>{{cite journal | last = Wells | first = R.J.D.|author2=J.R. Rooker | title = Spatial and temporal patterns of habitat use by fishes associated with Sargassum mats in the northwestern Gulf of Mexico | journal=Bulletin of Marine Science | volume = 74 | issue = 1 | pages = 81–99 | year = 2004 | url = http://www.tamug.edu/rooker/pdf/DavePaperBMS2004.pdf | access-date =22 May 2009 }}</ref> As the fish grow, they often move to more inshore lagoons and reefs, before slowly making their way to deeper outer reefs at the onset of sexual maturity.<ref name = "Carrib"/> Absolute growth rates are not well known, but the species has all the adult characteristics by a length of 59.3 mm.<ref>{{cite journal | last = Assem | first = S.S. | title = The reproductive biology and histological characteristics of pelagic carangid female ''Caranx crysos'' from the Egyptian Mediterranean Sea | journal=Journal of the Egyptian German Society of Zoology | volume = 31 | issue = C | pages = 195–215 | year = 2000 | issn = 1110-5348 }}</ref> In all cases studied, there are more females in the adult population than males, with female to male ratios ranging from 1.15F:1M to 1.91F:1M.<ref name = "goodwin2"/> Annual mortality rates for the population in the Gulf of Mexico range from 0.41 to 0.53. The oldest known individual was 11 years old based on otolith rings.<ref name = "goodwin"/>

==Relationship to humans== The blue runner is a highly important species to commercial fisheries throughout parts of its range. Due to its abundance, it may be one of the primary species in a fishery. The availability of fisheries statistics for the species is variable throughout its range, with the Americas having separate statistics kept for the species, while in Africa and Europe, it is lumped in with other carangids in statistics.<ref name = "fisheries">{{cite web | last = Fisheries and Agricultural Organisation | title = Global Production Statistics 1950–2007 | work = Blue runner | publisher = FAO | url = http://www.fao.org/figis/servlet/TabSelector | access-date = 19 May 2009 | archive-date = 15 May 2012 | archive-url = https://web.archive.org/web/20120515030053/http://www.fao.org/figis/servlet/TabSelector }}</ref> In the Americas, recent catch data suggests an increased amount of the species is being taken (or reported), with the 2006 and 2007 catch averaging between 6000 and 7000 tonnes, while during the 1980s and 1990s, the annual catch was rarely greater than 1000 tonnes.<ref name = "fisheries"/> Research on the fisheries of local regions has shown how important the fish is to certain fisheries. Artisanal fisheries in Santa Catarina Island have shown blue runner to be third-most important and abundant species, making up 5.6% of landings, or 4.38 tonnes.<ref name="Martins 2008 413–423"/> Even subsistence fisheries at the edge of its range in Brazil show a catch of 388 kg in two years from beach seines.<ref>{{cite journal | last = Tubino | first = R.D. |author2=C. Monteiro |author3=L.E.D. Moraes |author4=E.T. Paes | title = Artisanal fisheries production in the coastal zone of Itaipu, Niteroi, RJ, Brazil | journal=Brazilian Journal of Oceanography | volume = 55 | issue = 3 | pages = 187–197 | year = 2007 | url = http://www.scielo.br/pdf/bjoce/v55n3/v55n3a03.pdf| doi=10.1590/s1679-87592007000300003| doi-access = free }}</ref> Throughout its range, the blue runner is commercially taken by haul seines, lampara nets, purse seines, gill nets, and hook-and-line methods.<ref name = "FAO"/> The fish is sold at market either fresh, dried, or smoked, or as fishmeal, oil or bait.<ref name = "Fishid"/>

Blue runner is also of high importance to recreational fisheries, with anglers often taking the species both for food and to use as bait. The blue runner has a reputation as an excellent gamefish on light tackle, taking both fish baits and a variety of lures, including hard-bodied bibbed lures, spoons, metal jigs, and soft plastic jigs.<ref>{{cite book | last = Ristori | first = Al | title = Complete Guide to Saltwater Fishing | publisher=Woods N' Water, Inc. | year = 2002 | page = 59 | isbn = 0-9707493-5-X }}</ref> The species is also a target for light tackle saltwater fly fishermen, and can push lightweight fly tackle to its limits.<ref>{{cite book | last = Thomas Jr. | first = E. Donnall |author2=E. Donnall Thomas | title = Redfish, Bluefish, Sheefish, Snook: Far-Flung Tales of Fly-Fishing Adventure | publisher=Skyhorse Publishing Inc | year = 2007 | page = 256 | isbn = 978-1-60239-119-2 }}</ref> The IGFA world record for blue runner stands at 5.05 kg (11 lb, 2 oz) caught off Dauphin Island by Stacey Moiren in 1997,<ref>{{cite web |title=Record Details |url=http://wrec.igfa.org/WRecDetail.aspx?uid=18730&cn=Runner,%20blue#.W-pT37aZMcg |website=igfa.org |publisher=International Game Fish Association}}</ref> previous records have also come from the eastern North Atlantic.<ref>{{cite web |title=Record History |url=http://wrec.igfa.org/WRecHistory.aspx?lc=All-Tackle&cn=Runner,%20blue |website=igfa.org |publisher=International Game Fish Association |access-date=13 November 2018}}</ref> The blue runner is used extensively as live bait for larger fish, including billfish, cobia, and amberjack. It is considered a fairly low-quality table fish,<ref name = "FAO"/> and larger specimens are known to carry the ciguatera toxin in their flesh, with several cases reported from the Virgin Islands.<ref>{{cite journal | last = Morris | first = J.G. |author2=P. Lewin |author3=C.W. Smith |author4=P.A. Blake |author5=R. Schneider | title = Ciguatera Fish Poisoning – Epidemiology of the Disease on St. Thomas, United States Virgin Islands | journal= The American Journal of Tropical Medicine and Hygiene| volume = 31 | issue = 3 | pages = 574–578 | year = 1982 | issn = 0002-9637 | doi = 10.4269/ajtmh.1982.31.574 | pmid = 7200733 }}</ref>

==References== {{reflist}}

==External links== *[http://www.gma.org/fogm/Caranx_crysos.htm Blue runner (''Caranx crysos'')] at [http://www.gma.org Gulf of Maine Research Institute] *[https://web.archive.org/web/20090601221102/http://indian-river.fl.us/fishing/fish/jackblue.html Blue runner (''Caranx crysos'')] at [http://indian-river.fl.us Indian River] *[http://www.fishing-boating.com/baitprofiles/bluerunner.htm Blue runner (''Caranx crysos'')] {{Webarchive|url=https://web.archive.org/web/20210915195739/http://www.fishing-boating.com/baitprofiles/bluerunner.htm |date=15 September 2021 }} at [http://www.fishing-boating.com Fishing-boating.com] {{Webarchive|url=https://web.archive.org/web/20210915195740/http://www.fishing-boating.com/ |date=15 September 2021 }} *[http://www.combat-fishing.com/fishencyclo1/jacks/bluerunner.html Blue runner (''Caranx crysos'')] at [http://www.combat-fishing.com Combat Fishing] * {{sealifephotos|126802}}

blue runner Category:Fauna of Portugal Category:Fish of the Atlantic Ocean Category:Fish of the Mediterranean Sea Category:Marine fish of Nicaragua Category:Fish of Aruba blue runner Category:Taxa named by Samuel Latham Mitchill