The Atlantic horse mackerel (''Trachurus trachurus''), also known as the European horse mackerel or common scad, is a species of

jack mackerel Jack mackerels or saurels are marine fish in the genus ''Trachurus'' of the family Carangidae. The name of the genus derives from the Greek words ''trachys'' ("rough") and ''oura'' ("tail"). Some species, such as ''T. murphyi'', are harvested i ...

in the family

Carangidae The Carangidae are a family of ray-finned fish which includes the jacks, pompanos, jack mackerels, runners, and scads. It is the largest of the six families included within the order Carangiformes. Some authorities classify it as the only family ...

, the jacks, pompanos and trevallies. It is found in the eastern Atlantic Ocean off Europe and Africa and into the south-eastern Indian Ocean. It is an important species in commercial fisheries and is listed as a

Vulnerable species A vulnerable species is a species which has been categorized by the International Union for Conservation of Nature as being threatened with extinction unless the circumstances that are threatening its survival and reproduction improve. Vulnera ...

The IUCN Red List of Threatened Species The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...

Description

The Atlantic horse mackerel has quite a slender, quite compressed body with a large head in which the rear of the upper jaw reaches the front of the eye and the lower jaw projects beyond the upper jaw. The eye has a well developed adipose eyelid. It has two

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

s, the first is tall and has seven thin spines, with the final spine being much shorter than the others. The second dorsal fin is separated from the first by a narrow gap and is considerably longer than the first with 29-33 soft rays. The

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as see ...

is about as long as the second dorsal fin and there are two separate spines at its anterior end. The moderately sized

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two ...

has a single spine and five soft rays and has its origin below the end of the

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

base. A curved line of 33–40 bony scutes runs from the head to the tail, each having a small spine which increase in size and become bonier towards the tail. The

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

has a total of 66–67 scales, of which 31–36 are scutes. It is dark blue in colour with silvery flanks and a white belly, there is a dark spot on the operculum. This species attains a maximum fork length of , although they are normally around and a weight of .

Distribution

The Atlantic horse mackerel occurs in the north and eastern

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

, the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on ...

and Sea of Marmara and the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Rom ...

. In the Atlantic it is found from

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...

where it may extend around the

Cape of Good Hope The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa. A common misconception is that the Cape of Good Hope is ...

along the southern African

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by ...

coast

Maputo Maputo (), formerly named Lourenço Marques until 1976, is the capital, and largest city of Mozambique. Located near the southern end of the country, it is within of the borders with Eswatini and South Africa. The city has a population of 1,0 ...

Mozambique Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi ...

. However, if ''

Trachurus capensis The Cape horse mackerel (''Trachurus capensis'') is a mackerel-like species in the family Carangidae. It is a pelagic species of the south eastern Atlantic Ocean which is a target of fisheries, mainly as bycatch. Description The Cape horse macke ...

'' is considered to be a valid species then this species is restricted to the north east Atlantic. It has been recorded in

Cape Verde , national_anthem = () , official_languages = Portuguese , national_languages = Cape Verdean Creole , capital = Praia , coordinates = , largest_city = capital , demonym ...

but is thought to occur there only as a vagrant.

Habitat and biology

The Atlantic horse mackerel is a benthopelagic species which normally occurs over sandy substrates at depths of , although it has been reported as deep as and it is sometimes found nearer the surface waters. It is a migratory species, moving northwards in the summer months and returning southwards when the sea temperature starts to fall. In the north east Atlantic two stocks are recognised, the western stock

spawns Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquati ...

in a wide area from Ireland to the

Bay of Biscay The Bay of Biscay (), known in Spain as the Gulf of Biscay ( es, Golfo de Vizcaya, eu, Bizkaiko Golkoa), and in France and some border regions as the Gulf of Gascony (french: Golfe de Gascogne, oc, Golf de Gasconha, br, Pleg-mor Gwaskogn), ...

in the early Spring and moves northward to the southern coats of Norway and the northern

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian ...

in the summer. The North Sea stock spawns in the southern part of the North Sea during the summer and then migrates northwards into the central North Sea, the

Skagerrak The Skagerrak (, , ) is a strait running between the Jutland peninsula of Denmark, the southeast coast of Norway and the west coast of Sweden, connecting the North Sea and the Kattegat sea area through the Danish Straits to the Baltic Sea. T ...

and the Kattegat. Off Mauritania this species has its main spawning season in November to January while the related Cunene horse mackerel (''Trachurus trecae'') spawns in June and August. Off Ireland spawning occurs irregularly during the summer from June to August reaching its peak in July. The females spawn in batches, each of up to 140,000 eggs and hatching larvae in length. Spawning is indeterminate meaning that the total number of eggs a female can produce is dependent on factors which can change over the course of a spawning season. The eggs and larvae are

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...

. The juveniles of thus species frequently often shoal with the juveniles of other fish species, mainly

Atlantic herring Atlantic herring (''Clupea harengus'') is a herring in the family Clupeidae. It is one of the most abundant fish species in the world. Atlantic herrings can be found on both sides of the Atlantic Ocean, congregating in large schools. They can ...

(''Clupea clupea'') and with other species of horse mackerels such as the Mediterranean horse mackerel (''T. mediterraneus'') and blue jack mackerel (''T. picturatus''). Juveniles are also often encountered sheltering in the tentacles of

jellyfish Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbre ...

. In South Africa the maximum recorded age is 24 years while 40 years of age has been recorded in the northeast Atlantic. They are thought to breed from two to four years old for females. Off Mauritania, the juveniles are caught at depths of while mature fish are taken in shallower waters of less than .The age and growth of the Atlantic horse mackerel vary across its extensive range and are affected by the levels to which stocks are exploited. The diet of this species, in both juveniles and adults, is

copepods Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (inhabiting sea waters), some are benthic (living on the ocean floor), a number of species have p ...

, shrimps, small fishes and

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fittin ...

s. An examination of the stomach contents of Atlantic horse mackerels caught in the

Aegean Sea The Aegean Sea ; tr, Ege Denizi ( Greek: Αιγαίο Πέλαγος: "Egéo Pélagos", Turkish: "Ege Denizi" or "Adalar Denizi") is an elongated embayment of the Mediterranean Sea between Europe and Asia. It is located between the Balkans ...

recorded a total of 60 different prey species which belonged to five major systematic groups,

polychaetes Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made ...

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean g ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is est ...

arrow worms The Chaetognatha or chaetognaths (meaning ''bristle-jaws'') are a phylum of predatory marine worms that are a major component of plankton worldwide. Commonly known as arrow worms, about 20% of the known Chaetognatha species are benthic, and can ...

and

bony fish Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartil ...

Copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (inhabiting sea waters), some are benthic (living on the ocean floor), a number of species have ...

s, Euphasids and Mysids made up the highest percentage of food eaten. Bony fish were the secondmost numerous food ingested, while polychaeta and arrow worms were infrequently recorded food items. The diet showed very little seasonal variation with copepods and mysids making up the largest proportion of prey throughout the year, with fishes being most frequent prey except in the spring. Larger fish – those over – feed largely on the larvae of bony fishes. No less than 45 species of copeopod were identified in this study, and ''

Acartia clausi ''Acartia clausi'' is a species of marine copepod belonging to the family Acartiidae. This species was previously thought to have a worldwide distribution but recent research has restricted its range to coastal regions of the north-eastern Atlan ...

'' and '' Oncea media'' were numerous and important throughout the year. Crustaceans were the most important prey to be eaten by this species in all seasons, however, bony fish were the most important prey items for larger fish. Abstract

Taxonomy and naming

The Atlantic horse mackerel is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specim ...

of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

Trachurus Jack mackerels or saurels are marine fish in the genus ''Trachurus'' of the family Carangidae. The name of the genus derives from the Greek words ''trachys'' ("rough") and ''oura'' ("tail"). Some species, such as ''T. murphyi'', are harvested in ...

'' but when

Constantine Samuel Rafinesque Constantine Samuel Rafinesque-Schmaltz (; October 22, 1783September 18, 1840) was a French 19th-century polymath born near Constantinople in the Ottoman Empire and self-educated in France. He traveled as a young man in the United States, ultimat ...

created the genus in 1810 he used ''Trachurus saurus'' as the type species but

Carolus Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, th ...

had used the name '' Scomber saurus'' and had already described ''Scomber trachurus'' so Rafinesque's name was invalid. The genus ''Trachurus'' is part of the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus Genus ( plural genera ) is a taxonomic rank used in the biological classifica ...

Caranginae Caranginae is a subfamily of ray-finned fish from the family Carangidae which consists of twenty genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In th ...

of the family Carangidae, which is the largest family in the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

Carangiformes Carangiformes is an order of the ray-finned fishes. The order is part of a clade which is a sister clade to the Ovalentaria, the other orders in the clade being Synbranchiformes, Anabantiformes, Istiophoriformes and Pleuronectiformes. The Carangi ...

. The

generic Generic or generics may refer to: In business * Generic term, a common name used for a range or class of similar things not protected by trademark * Generic brand, a brand for a product that does not have an associated brand or trademark, other ...

and specific names are a compound of the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

''trachys'' meaning "rough" and ''oura'' meaning "tail", this appears to be an ancient name for horse mackerels, presumably in reference to the spiny scutes on the caudal peduncle. The common name horse mackerel has been said to derive from the belief that other fishes rode on its back but it may derive from the old Dutch word ''Horsmakreel'' which means a mackerel which spawns over a shallow or bank, a ''hors'', and this was taken into

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ...

as "horse mackerel". The Cape horse mackerel (''Trachurus capensis'') is considered to be the

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

''T. trachurus capensis'' of the Atlantic horse mackerel by some authorities and it is thought that there is no adequate series of these specimens of this taxa along the coast of Africa available to confirm the validity of this taxon.

Fisheries

The Atlantic horse mackerel is fished for commercially using trawls, longlines, purse seines (using artificial light), traps and on line gear. In 1999 the

Food and Agriculture Organization The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...

stated that the total catch reported to it was 322 207 tonnes with the largest catches being in the Netherlands and in Ireland. There is a total allowable catch (TAC) in the North Sea for this species and landings have consistently been below this level but the TAC is not in line with the scientific advice. There have been calls to create a management plan for the Atlantic horse mackerel in the North Sea but currently there are no specific management objectives for it. The stock needs to be assessed and management objectives should be set before the fishery can be shown to be sustainable.

Conservation

The

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

classify the Atlantic horse mackerel as Vulnerable because even if there has been no decline in the population in European waters there have been greater than ninety percent declines off the West African coast which means that this species will have undergone a decline of at least 35-40% over the past three generation lengths, which are estimated at 30–35 years. The

International Council for the Exploration of the Sea The International Council for the Exploration of the Sea (ICES; french: Conseil International de l'Exploration de la Mer, ''CIEM'') is a regional fishery advisory body and the world's oldest intergovernmental science organization. ICES is headqua ...

(ICES) classifies the population of this species as below the safe biological limit for exploitation. The populations are experiencing a slow decline with increased fishing pressure at the maximum sustainable yield since 2006 with low recruitment since 2004.

Human uses

The Atlantic horse mackerel is consumed fresh. It may be preserved by freezing, salting and drying,

smoking Smoking is a practice in which a substance is burned and the resulting smoke is typically breathed in to be tasted and absorbed into the bloodstream. Most commonly, the substance used is the dried leaves of the tobacco plant, which have b ...

and canning. It can be prepared by frying, broiling or baking. The flesh is said to have a pleasant flavour with an oily delicate texture which is a good source of

omega-3 fatty acid Omega−3 fatty acids, also called Omega-3 oils, ω−3 fatty acids or ''n''−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond, three atoms away from the terminal methyl group in their chem ...

s. Nutritionally 100g of the flesh of the Atlantic horse mackerel provides 97 kcal of energy and is made up of: Chicharros en escabeche

*Water: 77.4 g *Protein: 19.8 g *Fat: 2 g *

Cholesterol Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell memb ...

: 64.4 mg *Total minerals: 1.3 g *

Phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ea ...

: 224 mg In Iberia it may be prepared as an

escabeche __NOTOC__ Escabeche is the name for a number of dishes in Spanish, Portuguese, Filipino and Latin American cuisines, consisting of marinated fish, meat or vegetables, cooked or pickled in an acidic sauce (usually with vinegar), and colored w ...

while some are exported to Japan as ''aji'' to be used in

sushi is a Japanese dish of prepared , usually with some sugar and salt, accompanied by a variety of , such as seafood, often raw, and vegetables. Styles of sushi and its presentation vary widely, but the one key ingredient is "sushi rice," also ...

. They are also an important ingredient in Sicilian cuisine.

References

{{Authority control Atlantic horse mackerel Fish of the East Atlantic Fish of the Mediterranean Sea Fish of the Black Sea Fish of the North Sea Marine fish of Europe Marine fish of Africa Atlantic horse mackerel Atlantic horse mackerel eu:Txitxarro