The Arabian scad (''Trachurus indicus'') 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 in ...

from the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Carangidae which is found in the Western Indian Ocean.

Description

The Arabian scad has an elongate and slightly compressed body with the upper and lower profiles being roughly equal. The eye is moderately large and has a well-developed adipose eyelid which normally covers almost all of the eye apart from a vertical oval with the pupil in the centre. It has a reasonably wide upper jaw which extends to underneath the forward anterior edge of the eye. The mouth is equipped with small teeth, having a single row in each jaw. It has two separate

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 having 8 spines with the second having a single spine and 28 to 35 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 s ...

has 2 detached spines to its front followed by a single spine and 24 to 30 soft rays. 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 ...

s are as long or longer than the length of the head. The scales in the lateral line and large and form scutes. It has a black spot on the upper margin of the operculum and the upper part of the body is dark dusky to almost black or greenish to bluish while the flanks and belly are silvery to white. The fins are not coloured It grows to a maximum

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

of .

Distribution

The Arabian scad is found in the western Indian Ocean from the

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; ...

and Somalia through the

Persian Gulf The Persian Gulf ( fa, خلیج فارس, translit=xalij-e fârs, lit=Gulf of Fars, ), sometimes called the ( ar, اَلْخَلِيْجُ ٱلْعَرَبِيُّ, Al-Khalīj al-ˁArabī), is a mediterranean sea in Western Asia. The bo ...

east as far as Pakistan and south to the

Saya de Malha Bank The Saya de Malha Bank (also the Sahia de Malha Bank, modern Portuguese: ''saia de malha'', English: ''mesh skirt'') or Mesh Skirt Bank, is one of the largest submerged ocean banks in the world, a part of the vast undersea Mascarene Plateau. ...

. The species was reported for the first time in 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 the ...

in 2004 off Turkey.Atlas of Exotic Fishes in the Mediterranean Sea (Trachurus indicus). 2nd Edition. 2021. 366p. CIESM Publishers, Paris, Monaco.https://ciesm.org/atlas/fishes_2nd_edition/Trachurus_indicus.pdf

Habitat and biology

The Arabian scad is a semi-pelagic, demersal fish which forms schools in nearshore waters at depths between , but mostly frequently recorded in waters of less than depth. It apparently is not recorded where the water temperature is below or where the saturation level of oxygen is less than 30%. Sexual maturity is reached in the fish's first year of life when it attains a length of . In the seas off Oman, however, sexual maturity was attained at about in total length for males and for females.

Spawning 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 aqua ...

takes place in the

Gulf of Oman The Gulf of Oman or Sea of Oman ( ar, خليج عمان ''khalīj ʿumān''; fa, دریای عمان ''daryâ-ye omân''), also known as Gulf of Makran or Sea of Makran ( ar, خلیج مکران ''khalīj makrān''; fa, دریای مکرا� ...

from August to November, peaking during September and October. They reach is at least seven years of age and the estimated generation length is three and a half years. Its diet consists largely of fish fry and small crustaceans.

Fisheries

The Arabian scad is caught as bycatch in some fisheries and is often discarded due to its low market value. It, and two congeneric species, are targeted by purse seine fisheries in the

Gulf of Suez The Gulf of Suez ( ar, خليج السويس, khalīǧ as-suwais; formerly , ', "Sea of Calm") is a gulf at the northern end of the Red Sea, to the west of the Sinai Peninsula. Situated to the east of the Sinai Peninsula is the smaller Gulf o ...

, while in Somalia it is targeted by subsistence and artisanal fisheries.

Taxonomy

''Trachurus indicus'' was described in 1966 by the

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 33,400 species of fish had been described as of October ...

V.V. Nekrasov as the subspecies ''indicus'' of ''

Trachurus mediterraneus The Mediterranean horse mackerel (''Trachurus mediterraneus''), also known as the Black Sea horse mackerel, horse mackerel, Mediterranean scad, common scad, or simply scad, is a species of mackerel in the family Carangidae found in the eastern At ...

'' with the

type locality Type locality may refer to: * Type locality (biology) * Type locality (geology) See also * Local (disambiguation) * Locality (disambiguation) {{disambiguation ...

given as the

Gulf of Aden The Gulf of Aden ( ar, خليج عدن, so, Gacanka Cadmeed 𐒅𐒖𐒐𐒕𐒌 𐒋𐒖𐒆𐒗𐒒) is a deepwater gulf of the Indian Ocean between Yemen to the north, the Arabian Sea to the east, Djibouti to the west, and the Guardafui Chan ...

. It is now considered a valid species.

References

{{taxonbar, from=Q2404924 Trachurus delagoa Fish described in 1970