Mackerel scad
Encyclopedia
The Mackerel scad, Decapterus macarellus, is a species
of fish
of the family
, Carangidae
. While Mackerel scad are considered gamefish, they are usually used as bait.
, located between the dorsal
and caudal fins. Mackerel scad have 9 spines
and 31-36 rays on their dorsal fins, while there are 7 spines and 27-30 ray's on their anal fins.
The mackerel scad's fins are black metallic to blue green and its belly is white. The edge of the operculum
has a small, black spot, while there are no spots on the lateral line
. Mackerel scad's caudal fins have been described as reddish to yellow-green.
and Bermuda
, south to Rio de Janeiro
, although they do not seem common in the Gulf of Mexico
. In the eastern Atlantic, mackerel scad have been found off St. Helena, Ascension island
, and Cape Verde
. They have also been recorded in the Gulf of Guinea
, The Azores, and Madeira
. In the Indian ocean
, mackerel scad have been found in the Red sea
and the Gulf of Aden
they are also known from South Africa
, the Mascarenes, the Seychelles
, and Sri Lanka
. In the eastern Pacific, they are known from Revillagigedo Island
, the Gulf of California
, and the coast of Ecuador
.
Mackerel scad usually live in sub-tropical seas at depths up to 400 m. They prefer clear water, and are frequently found around island
s. Although mackerel scad have been found at the surface, they are usually caught at depths between 40 and 200 meters. They feed mainly on zooplankton
.
, and are more often used as bait, since large gamefish such as the Blue-spotted Grouper
, Giant trevally
, and the Onespot snapper are all known to feed on them.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, Carangidae
Carangidae
Carangidae is a family of fish which includes the jacks, pompanos, jack mackerels, and scads.They are marine fish found in the Atlantic, Indian and Pacific Oceans...
. While Mackerel scad are considered gamefish, they are usually used as bait.
Description
The largest mackerel scad recorded was 46 cm long. They have elongated bodies that look somewhat circular when viewed head on. They are distinguishable by a small, detached finFin
A fin is a surface used for stability and/or to produce lift and thrust or to steer while traveling in water, air, or other fluid media, . The first use of the word was for the limbs of fish, but has been extended to include other animal limbs and man-made devices...
, located between the dorsal
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
and caudal fins. Mackerel scad have 9 spines
Spine (zoology)
A spine is a hard, thorny or needle-like structure which occurs on various animals. Animals such as porcupines and sea urchins grow spines as a self-defense mechanism. Spines are often formed of keratin...
and 31-36 rays on their dorsal fins, while there are 7 spines and 27-30 ray's on their anal fins.
The mackerel scad's fins are black metallic to blue green and its belly is white. The edge of the operculum
Operculum (fish)
The operculum of a bony fish is the hard bony flap covering and protecting the gills. In most fish, the rear edge of the operculum roughly marks the division between the head and the body....
has a small, black spot, while there are no spots on the lateral line
Lateral line
The lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...
. Mackerel scad's caudal fins have been described as reddish to yellow-green.
Distribution and habitat
The mackerel scad's range covers most of the world's oceans. In the western Atlantic, they have been found off Nova ScotiaNova Scotia
Nova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...
and Bermuda
Bermuda
Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...
, south to Rio de Janeiro
Rio de Janeiro
Rio de Janeiro , commonly referred to simply as Rio, is the capital city of the State of Rio de Janeiro, the second largest city of Brazil, and the third largest metropolitan area and agglomeration in South America, boasting approximately 6.3 million people within the city proper, making it the 6th...
, although they do not seem common in the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
. In the eastern Atlantic, mackerel scad have been found off St. Helena, Ascension island
Ascension Island
Ascension Island is an isolated volcanic island in the equatorial waters of the South Atlantic Ocean, around from the coast of Africa and from the coast of South America, which is roughly midway between the horn of South America and Africa...
, and Cape Verde
Cape Verde
The Republic of Cape Verde is an island country, spanning an archipelago of 10 islands located in the central Atlantic Ocean, 570 kilometres off the coast of Western Africa...
. They have also been recorded in the Gulf of Guinea
Gulf of Guinea
The Gulf of Guinea is the northeasternmost part of the tropical Atlantic Ocean between Cape Lopez in Gabon, north and west to Cape Palmas in Liberia. The intersection of the Equator and Prime Meridian is in the gulf....
, The Azores, and Madeira
Madeira
Madeira is a Portuguese archipelago that lies between and , just under 400 km north of Tenerife, Canary Islands, in the north Atlantic Ocean and an outermost region of the European Union...
. In the Indian ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
, mackerel scad have been found in the Red sea
Red Sea
The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...
and the Gulf of Aden
Gulf of Aden
The Gulf of Aden is located in the Arabian Sea between Yemen, on the south coast of the Arabian Peninsula, and Somalia in the Horn of Africa. In the northwest, it connects with the Red Sea through the Bab-el-Mandeb strait, which is about 20 miles wide....
they are also known from South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, the Mascarenes, the Seychelles
Seychelles
Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
, and Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
. In the eastern Pacific, they are known from Revillagigedo Island
Revillagigedo Island
Revillagigedo Island is an island in the Alexander Archipelago in Ketchikan Gateway Borough of the southeastern region of the U.S. state of Alaska. Running about 89 km north-south and 48 km east-west, it is 2,754.835 km² in area, making it the 12th largest island in the United...
, the Gulf of California
Gulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
, and the coast of Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
.
Mackerel scad usually live in sub-tropical seas at depths up to 400 m. They prefer clear water, and are frequently found around island
Island
An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, cays or keys. An island in a river or lake may be called an eyot , or holm...
s. Although mackerel scad have been found at the surface, they are usually caught at depths between 40 and 200 meters. They feed mainly on zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
.
Relationship with humans
Mackerel scad are fairly important both to fisheries and to sportfishing. They can be used as food, but are known to carry ciguateraCiguatera
Ciguatera is a foodborne illness caused by eating certain reef fishes whose flesh is contaminated with toxins originally produced by dinoflagellates such as Gambierdiscus toxicus which lives in tropical and subtropical waters. These dinoflagellates adhere to coral, algae and seaweed, where they are...
, and are more often used as bait, since large gamefish such as the Blue-spotted Grouper
Blue-Spotted Grouper
Cephalopholis argus, also known as: Blue-spotted Grouper, Argus Grouper, Peacock Hind, Peacock Grouper or Peacock Rockcod is a fish from the Indo-Pacific which is variously a commercial gamefish, an invasive species and occasionally an aquarium resident...
, Giant trevally
Giant trevally
The giant trevally, Caranx ignobilis , is a species of large marine fish classified in the jack family, Carangidae...
, and the Onespot snapper are all known to feed on them.
External links
- http://www.gma.org/fogm/Decapterus_macarellus.htm
- http://www.thejump.net/id/mackerel-scad.htm
- http://www.fishbase.org/summary/SpeciesSummary.php?id=993