Pacific jack mackerel

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Pacific jack mackerel
Pacific Jack Mackerel School, 2007.jpg
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Carangiformes
Family: Carangidae
Genus: Trachurus
Species:
T. symmetricus
Binomial name
Trachurus symmetricus
(Ayres, 1855)
Synonyms
  • Caranx symmetricus,
    Ayres, 1855
  • Decapterus polyaspis,
    Walford & Myers, 1944
  • Trachurus symmetricus symmetricus,
    (Ayres, 1855)
  • Trachurus picturatus symmetricus,
    (Ayres, 1855)

The Pacific jack mackerel (Trachurus symmetricus), also known as the Californian jack mackerel or simply jack mackerel, is an abundant species of pelagic marine fish in the jack family, Carangidae. It is distributed along the western coast of North America, ranging from Alaska in the north to the Gulf of California in the south, inhabiting both offshore and inshore environments. The Pacific jack mackerel is a moderately large fish, growing to a maximum recorded length of 81 cm, although commonly seen below 55 cm. It is very similar in appearance to other members of its genus, Trachurus , especially T. murphyi , which was once thought to be a subspecies of T. symmetricus, and inhabits waters further south. Pacific jack mackerel travel in large schools, ranging up to 600 miles offshore and to depths of 400 m, generally moving through the upper part of the water column.

Contents

Distribution and habitat

The Pacific jack mackerel is distributed through the eastern Pacific Ocean from Alaska in the north, south to the western North American seaboard to the Baja California peninsula in the Gulf of California. [2] It has been reported as far south as the Galápagos Islands, but at these latitudes it would be sympatric with T. murphyi, possibly resulting in confusion of the two species. Pacific jack mackerel occur in both pelagic and inshore environments, often venturing up to 600 miles offshore and to known depths of 400 m. In more coastal environments, they are known to inhabit bays and very shallow waters. [3]

Description

The Pacific jack mackerel is very similar to all other members of Trachurus and a number of other carangid genera, having an elongated, slightly compressed body with both the dorsal and ventral profiles of the body having the same degree of curvature. [3] It is a medium-to-large-sized fish, growing to a maximum known length of 81 cm (32 in), although more commonly below 55 cm. [2] The two separate dorsal fins are composed of eight spines and one spine followed by 31 to 35 soft rays, respectively. The anal fin is composed of two spines anteriorly detached followed by one spine connected to 26 to 30 soft rays. In some larger individuals, the last few rays at the posterior of the soft dorsal and anal fins are almost entirely separate from the rest of the fin, forming finlets. The caudal fin is strongly forked, typical amongst Carangidae, while the ventral fin consists of one spine and five soft rays. The pectoral fin terminates before the front of the anal fin, having 22 to 24 rays in total. The lateral line dips strongly after the pectoral fin, having 50 to 53 scales on the upper section and 43 to 52 keeled scutes posteriorly. The species' teeth are minute, with a patch of teeth on the tongue in a narrow club-shaped strip. There are 24 vertebrae in total. [3]

Pacific jack mackerel are metallic blue to olive-green dorsally, becoming more silvery ventrally, before transitioning to a white belly. The top of the head and area near eye is quite dark with a dark spot on the upper rear of the gill cover. The fins are mostly hyaline to dusky, although caudal fin may be yellow to reddish. [4]

Relationship to humans

A swirling mass of Pacific jack mackerel form a bait ball which draws feeding seabirds and marine mammals Trachurus symmetricus baitball.jpg
A swirling mass of Pacific jack mackerel form a bait ball which draws feeding seabirds and marine mammals

Pacific jack mackerel are fished commercially as well as for sport. They are often caught on baited hook from piers and boats, and also while salmon trolling. Commercial fishing occurs along the coast. Large individuals often move inshore and north in the summer. Pacific jack mackerel is canned in the same manner as salmon. Fish are cleaned, gutted and finned, then packed into cans with salt and water.[ citations needed ]

History

Before 1947, the pacific jack mackerel was of minor importance. It was referred to as the horse mackerel, and had little market appeal. However, in 1948, the US Food and Drug Administration decided to allow the use of "jack mackerel" on all labeling, and that affected its appeal. The new label, combined with low catches of Pacific sardine in 1947-48 and increased catches of pacific jack mackerel during the same time, resulted in the fish gaining importance. [5] In the past, mackerel consumption was considered a sign of low income. In the segregated American South, it was often associated with African Americans. Today, most of these stereotypes are gone.[ citation needed ]

As food

Pacific jack mackerel tastes similar to canned sardines. It may be used interchangeably with salmon or tuna in recipes. Jack mackerel is considered safer to consume than tuna because it is a smaller fish, and not a top predator, thus avoiding accumulation of heavy metals such as mercury.[ citation needed ]

Taxonomy and naming

The Pacific jack mackerel is classified within the genus Trachurus, commonly known as the horse mackerels or jack mackerels. Trachurus is part of the jack family Carangidae, which is classified within the order Carangiformes. [6] Recent genetic studies have divided the Carangidae into four subfamilies, with the genus Trachurus falling into Caranginae (or tribe Carangini), being most closely related to the 'scads' of the genera Decapterus and Selar . [7] [8]

The species was first scientifically described by William Orville Ayres in 1855 based on the holotype specimen taken from San Francisco Bay, California. [9] He named the species Caranx symmetricus, correctly identifying its relationship to the jacks, but incorporating it into what was later found to be the wrong genus. The fish was redescribed in 1944 under a different name, Decapterus polyaspis, from a specimen caught in Oregon, [4] which under the ICZN rules classifies as a junior synonym, and it is therefore discarded. In 1983, C. symmetricus was transferred to Trachurus symmetricus by William N. Eschmeyer and Earl Herald. The species has twice been treated as a subspecies; once as Trachurus picturatus symmetricus (a subspecies of the blue jack mackerel), and the second more commonly used subspecies of Trachurus symmetricus symmetricus. For many years, the latter was accepted as a valid combination, with Trachurus symmetricus murphyi considered to be a southern subspecies population. Mitochondrial DNA analysis has now confirmed these subspecies to be separate species, with T. s. murphyi now simply Trachurus murphyi , the Inca scad. The divergence time of these two species was deemed relatively recent, at around 250,000 years ago. [10]

T. symmetricus is known commonly as the 'Pacific jack mackerel' in reference to its distribution, with the species often called simply 'jack mackerel' or 'mackereljack' [2]

Related Research Articles

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Shrimp scad Species of fish

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Rainbow runner Species of fish

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<i>Alepes</i> Genus of fishes

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Yellowtail scad Species of fish

The yellowtail scad, is an abundant species of small inshore marine fish of the jack family, Carangidae. The species is widespread in the Indo-Pacific region from east Africa in the west to Hawaii in the east, extending north to Japan and south to Australia. The yellowtail scad is the only member of the monotypic genus Atule and is distinguished from similar species by a well-developed adipose eyelid and finlet-like extensions of the last rays of the dorsal and anal fins. It inhabits coastal areas such as bays and coral reefs, preying on small fishes and crustaceans. Spawning has been well studied in Hawaii, where fish enter bays to spawn, releasing up to 161,000 eggs each between March and October. The yellowtail scad is an important component of fisheries throughout its range, taken by a number of netting and hook-and-line methods. It is a prized food fish in some regions and is cooked or preserved by a variety of methods.

<i>Carangoides</i> Genus of fishes

Carangoides is a genus of tropical to subtropical marine fishes in the jack family, Carangidae. They are small- to large-sized, deep-bodied fish characterised by a certain gill raker and jaw morphology, often appearing very similar to jacks in the genus Caranx. They inhabit the subtropical and tropical regions of the Indian, Pacific, and Atlantic Oceans, often occupying coastal areas, including reefs, bays, and estuaries, rarely venturing far offshore. They are all predatory fishes, taking a variety of smaller fishes, crustaceans and cephalopods as prey. The genus was first erected in 1851 by Pieter Bleeker for an unknown taxon and currently contains 20 species. Many make up significant proportions of various fisheries, although a number of ciguatera cases have been attributed to them.

Green jack Species of fish

The green jack, also known as the horse jack, is an abundant species of coastal marine fish in the jack family Carangidae. The species is distributed in the eastern Pacific Ocean along the American coastline from Santa Cruz Island off California in the north to Peru in the south, as well as a number of islands including the Galapagos and recently, Hawaii. The green jack is distinguished from other similar carangid species by a number of features including gill raker and lateral line scale counts, and the presence of an adipose eyelid. It is a moderately large species, growing to at least 55 cm in length and 2.81 kg, although unconfirmed reports suggest a much larger maximum size. It lives in a wide range of continental shelf environments including estuaries, bays, reefs and offshore seamounts, living both pelagically and demersally. The green jack is a predatory species, preying on a variety of fish, crustaceans and cephalopods, as well as zooplankton. Most fish are sexually mature by the time they attain 38 cm, with spawning occurring between May and October. The species is of high importance to fisheries throughout its range, caught by pelagic trawls, a variety of netting methods and hook and line. The green jack is also of interest to anglers, taken by bait and lures, although is considered to only be fair in eating quality.

<i>Caranx</i> Genus of fishes

Caranx is a genus of tropical to subtropical marine fishes in the jack family Carangidae, commonly known as jacks, trevallies and kingfishes. They are moderate- to large-sized, deep-bodied fishes which are distinguished from other carangid genera by specific gill raker, fin ray and dentition characteristics. The genus is represented in the Pacific, Indian and Atlantic Oceans, inhabiting both inshore and offshore regions, ranging from estuaries and bays to deep reefs and offshore islands. All species are powerful predators, taking a variety of fish, crustaceans and cephalopods, while they in turn are prey to larger pelagic fishes and sharks. A number of fish in the genus have a reputation as powerful gamefish and are highly sought by anglers. They often make up high amounts of the catch in various fisheries, but are generally considered poor to fair table fishes.

Whitefin trevally Species of fish

The whitefin trevally, also known as the horse trevally, is a species of deep water offshore fish in the jack family Carangidae. The species inhabits the tropical to temperate waters of the Indo-Pacific and central Pacific, ranging from South Africa in the west to Hawaii in the east. The whitefin trevally is a moderate-sized fish, growing to 37 cm, and is distinguished by a number of morphological traits, including fin size, gill raker count, and colour. It inhabits the continental shelf and slope at depths to 200 m over sand and mud substrates, where it preys on fish, crustaceans, and cephalopods. Studies in Japan indicate a length at sexual maturity of 17.4 cm on average, with spawning occurring between May and October, with each individual spawning multiple times. Whitefin trevallies are of high importance to fisheries in Japan, where they are taken by trawlers, although the catch numbers have halved since the 1980s. It is of minor importance elsewhere throughout its range, but is considered a good table fish.

Blue trevally Species of fish

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Bumpnose trevally Species of fish

The bumpnose trevally, also known as the bumpnose kingfish or onion kingfish, is a species of relatively small inshore marine fish classified in the jack family Carangidae. The bumpnose trevally is fairly common in the tropical and subtropical waters of the Indo-west Pacific region, ranging from South Africa in the west to Japan and Samoa in the east. It is a small species by carangid standards, reaching a maximum known length of 32 cm, and can be distinguished from the similarly shaped Carangoides armatus by a distinct 'bump' on the snout, which gives the fish its common name. The species inhabits coastal waters, often living along bays and beaches, where it takes shrimp, small crabs, and juvenile fish as prey. The bumpnose trevally is of minor importance to fisheries throughout its range, taken by hook and line, trawls, and seine nets. It is also of minor importance to anglers, taken by baits from beaches and piers, and is considered a modest table fish.

Duskyshoulder trevally Species of fish

The duskyshoulder trevally or epaulet trevally, is a species of small inshore marine fish in the jack family, Carangidae. It is distributed through the eastern Indian and western Pacific Oceans, ranging from eastern India to northern Australia and Taiwan. It is relatively small by carangid standards, reaching only 27 cm maximum length, and can be distinguished by the large, black blotches on its shoulders. The duskyshoulder trevally is an inshore fish living in waters less than 50 m deep, over sandy substrates in bays and on the continental shelf. It is a predatory fish, taking demersal fishes, crustaceans, and cephalopods, with nothing known of its reproductive habits. It is of little value to fisheries, often taken as bycatch in prawn trawling operations.

Coachwhip trevally Species of fish

The coachwhip trevally, also known as the oblong trevally or oblique-banded trevally, is a species of inshore marine fish classified in the jack family Carangidae. The coachwhip trevally is distributed through the Indo-west Pacific region, ranging from South Africa in the west to Fiji and Japan in the east. It is a moderately large fish, growing to a known maximum length of 46 cm and can be distinguished from similar species by an array of detailed morphological features including dentition, fin ray counts and scale patterns. The coachwhip trevally inhabits coastal waters throughout its range, known to prefer estuarine waters in a number of localities. Nothing is known of its diet or reproductive biology, and is of little importance to fisheries, occasionally taken as bycatch in trawl and hook and line fisheries.

Island trevally Species of fish

The island trevally, island jack, thicklip trevally or false bluefin trevally is a widespread species of offshore marine fish classified in the jack family Carangidae. The island trevally is common through the tropical regions of the Indian and Pacific Oceans, 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 offshore islands, where it is found in lagoons 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 crustaceans. It is of moderate importance to fisheries throughout its range, often taken by trawls, hook-and-line, and various inshore netting methods, and is sold fresh or salted at market.

False scad Species of fish

The false scad, also known as the spotfin scad, ten-finned horse mackerel and yellow horse mackerel, is a species of medium-sized marine fish classified in the jack family Carangidae. The false scad is distributed throughout the tropical and temperate waters of the eastern Atlantic Ocean from Namibia in the south to Spain and throughout most of the Mediterranean in the north. The species has an atypical body form compared to other species of Caranx, and can be distinguished from these on its elongate 'scad-like' body shape alone. Distinguishing the species from members of Decapterus and Trachurus is more difficult, requiring detailed anatomical analysis. The false scad is known to grow to a length of 60 cm and a weight of 1 kg. The species lives both pelagically and demersally in continental shelf waters, ranging from depths of 15 to 200 m. It is a predatory fish, taking small fishes, crustaceans including euphausiids and shrimps, and cephalopods as its main prey, with significant dietary shifts as it ages. The false scad reaches sexual maturity at 2 years of age, with spawning occurring between April and July in shallow inshore waters, where the juveniles remain. The species is of major importance to fisheries throughout its range, but particularly from Morocco to Senegal, with annual catches ranging from 500 to 19000 t. The species is caught using trawls, seine nets and gill nets and sold fresh, frozen or salted.

<i>Chloroscombrus</i> Genus of fishes

Chloroscombrus is a genus containing two species of tropical to temperate water marine fish in the jack and horse mackerel family Carangidae. Both members are commonly known as bumpers or bumperfish, with one species endemic to the Atlantic and the other to the eastern Pacific. They have a convex ventral profile compared to most other carangids, with small oblique mouths and low dorsal and anal fins. Phylogenetic studies have found they are most closely related to the jacks of the genus Hemicaranx, with these genera plus Selar, Selaroides and possibly Alepes, making up a clade within the Caranginae subfamily. They are predatory fish which live in both inshore and offshore environments ranging from estuaries to the edge of the continental shelf, and are of moderate importance to fisheries.

Torpedo scad Species of fish

The torpedo scad, also known as the hardtail scad, finny scad, finletted mackerel scad or cordyla scad, is a species of moderately large marine fish classified in the jack and horse mackerel family, Carangidae. The torpedo scad is distributed throughout the tropical Indo-Pacific region, ranging from South Africa in the west to Tonga in the east, extending to Japan in the north and Australia in south. It is a schooling pelagic fish which occupies the surface layers of both inshore and offshore oceanic waters. The torpedo scad is easily identified by both its 'torpedo' shaped body and a series of detached finlets at the rear of both the dorsal and anal fins. The largest recorded individual was 80 cm long and weighed 4 kg, although it is more common at lengths less than 40 cm. It is a predatory species, taking a variety of fish, cephalopods and crustaceans by both active and filter feeding. There is a shift in diet as the species grow; however fish is the dominant prey in all size classes. Torpedo scad reach sexual maturity at 22 cm in females and 26.4 cm in males, with spawning occurring between March and July in India, where significant research into larval growth and morphometrics has been carried out.

Chilean jack mackerel Species of fish

The Chilean jack mackerel, sometimes called the Inca scad or Peruvian jack mackerel, is a species of jack mackerel in the genus Trachurus of the family Carangidae. Since the 1970s, it has become one of the world's more important commercial fish species. High volumes have been harvested, but the fishery may now be in danger of collapsing.

Yellowstripe scad Species of fish

The yellowstripe scad, also known as the yellowstripe trevally, yellow-banded trevally, smooth-tailed trevally, slender-scaled trevally and slender trevally, is a species of small inshore fish in the jack and horse mackerel family Carangidae, and the only member of the genus Selaroides. The yellowstripe trevally is distributed throughout the tropical waters of the Indo-West Pacific region, ranging from the Persian Gulf in the west to Vanuatu and New Caledonia in the east. The species is distinguished by its prominent lateral yellow band, and differs from the scads of the genus Selar in having a smaller eye and different dentition. The yellowstripe scad reaches a maximum recorded length of 22 cm, however is normally encountered at sizes less than 15 cm. Phylogenetic studies indicate the yellowstripe scad is closely related to the scads of the genus Selar, although its exact placement in the family Carangidae is less well agreed upon.

<i>Decapterus russelli</i> Species of fish

The Indian Scad, also known as the Northern mackerel scad, round scad, Russell's mackerel scad, slender scad or the three lined grunter, is a species of ray-finned fish of the genus Decapterus which is part of the family Carangidae and which occurs in the Indian Ocean. It has colonised the eastern Mediterranean through the Suez Canal. It is an important species in coastal fisheries throughout its range.

References

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  3. 1 2 3 Fischer, W.; F. Krupp; W. Schneider; C. Sommer; K. Carpenter; V.H. Niem (1995). Guía FAO para la identificación de especies para los fines de la pesca. Pacífico centro-oriental. Volumen III. Vertebrados – Parte 2. Rome: FAO. p. 985. ISBN   92-5-303675-3.
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  5. Blunt C.E. Jr. (1969) "The jack mackerel (Trachurus symmetricus) resource of the eastern North Pacific" Calif. Alar. Ees. Comm., 13 : 16-52.
  6. J. S. Nelson; T. C. Grande; M. V. H. Wilson (2016). Fishes of the World (5th ed.). Wiley. pp. 380–387. ISBN   978-1-118-34233-6.
  7. Reed, David L.; Carpenter, Kent E.; deGravelle, Martin J. (2002). "Molecular systematics of the Jacks (Perciformes: Carangidae) based on mitochondrial cytochrome b sequences using parsimony, likelihood, and Bayesian approaches". Molecular Phylogenetics and Evolution. USA: Elsevier Science. 23 (3): 513–524. doi:10.1016/S1055-7903(02)00036-2. PMID   12099802.
  8. Zhu, Shi-Hua; Wen-Juan Zing; Ji-Xing Zou; Yin-Chung Yang; Xi-Quan Shen (2007). "Molecular phylogenetic relationship of Carangidae based on the sequences of complete mitochondrial cytochrome b gene". Acta Zoologica Sinica. 53 (4): 641–650. Retrieved 3 January 2008.
  9. Ayres, William O. (1855). "Descriptions of new species of Californian fishes". Proceedings of the California Academy of Sciences. Series 1. 1 (1): 23–77.
  10. Poulin, E.; L. Cardenas; C.E. Hernandez; I. Kornfield; F. P.Ojeda (2004). "Resolution of the taxonomic status of Chilean and Californian jack mackerels using mitochondrial DNA sequence". Journal of Fish Biology. The Fisheries Society of the British Isles. 65 (4): 1160–1164. doi:10.1111/j.0022-1112.2004.00514.x.