Longfin crevalle jack
Encyclopedia
The longfin crevalle jack, Caranx fischeri, is a recently described species
of large marine
fish classified in the jack family, Carangidae
. It inhabits the subtropical waters of the east Atlantic Ocean
, ranging along the Africa
n coast from Mauritania
south at least to Moçamedes
in southern Angola
, with the species historically present in the Mediterranean Sea
. It is an inshore species, known to occasionally penetrate estuaries, possibly to spawn
. The species is very similar to the crevalle jack
, Caranx hippos, and is separated by its extended dorsal
and anal fin lobes as well as more detailed anatomical features including dorsal and anal fin ray counts. The fish is known to reach 127 cm in length and 20.9 kg
in weight. The longfin crevalle jack is a predatory fish, taking small fish as its main prey. Due to longstanding confusion between C. fischeri and C. hippos, the importance of each species to African fisheries is poorly understood, with a known combined catch in this region of between 2,233 and 10,054 tonne
s per year in 1995-2004. Like its close relatives, the species is considered a powerful gamefish and highly sought after, although their coarse flesh makes for relatively poor quality food
.
, 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
, a group of percoid
fishes in the order Perciformes
.
The species belongs to the "Caranx hippos complex" as defined by William Smith-Vaniz and Kent Carpenter, which includes C. fischeri, C. hippos and C. caninus
. The identity of the species was entangled with C. hippos until William Smith-Vaniz and Ken Carpenter described the species in full in 2007, anatomically setting it aside from C. hippos. The holotype
specimen is derived from a specimen collected in 1978 off Cameroon
, and was initially referred to C. hippos. The species has no synonym
s due to its recent description, but the species has been misidentified as both C. hippos and C. carangus (now synonymous with C. hippos). The specific epithet is in reference to Dr. Walter Fischer, a former official of the FAO
who initiated the Species Identification and Data Program. The naming of the new species was presented at an IGCC and FAO meeting. The species common name as defined by Smith-Vaniz and Carpenter is 'longfin crevalle jack', referring to the extended fin lobes which separates the species from the crevalle jack.
as measured by Smith-Vaniz and Carpenter in their description. Discussion on the angling
merits of the species in the same publication indicate that the species grows significantly larger, recorded up to 127 cm by anglers mistaking it for C. hippos. It has a body profile similar to most of the large species in Caranx, possessing a strongly compressed approximately oblong
form. The dorsal profile is much more convex than the ventral profile, with the caudal peduncle quite slender. The dorsal fin
is in two parts, the first consisting of 8 spines and the second of 1 spine followed by 21 to 24 soft rays. The dorsal and anal fin lobes are slightly elongated on the species, which distinguishes from the similar crevalle jack
. The anal fin consists of 2 detached spines anterior to the main bulk of the fin, which consists of 1 spine followed by 17 to 19 soft rays. The lateral line
is moderately arched anteriorly, with this section containing 50 to 73 scale
s, while the straight section has 0 to 16 scales and 24 to 41 scute
s. The breast is devoid of scales up to the origin of the pelvic fins and is separated from the base of the pectoral fins by a narrow band of scales. there are 20 to 25 gill raker
s in total and 24 vertebrae.
The longfin crevalle jack is olive to greenish blue in colour dorsally, fading to pale and white ventrally. The dorsal fin dark brown to grey while the anal fin is brownish yellow, becoming white towards the lobe. The caudal fin is brown-yellow and the pelvic fins white. The species has a dark spot both on its opercle
and lower pectoral fin rays.
, currently known to range from Mauritania
south to at least Moçamedes
in southern Angola
. Publications describing historical fish specimens collected in the Mediterranean confirm Caranx fischeri was present in this region, although no recent specimens are known. The species appears to be able to travel long distances, with one adult collected from Ascension Island
in the mid-Atlantic.
The longfin crevalle jack appears to be primarily an inshore species based the limited data available, although captures such as those in the Ascension Island indicate the species may live pelagically. In the inshore environment they are known from reef
s, as well as estuarine environments, possibly penetrating the upper reaches of river
s.
, other carangids and porgies of the family Sparidae. Small jacks, probably including C. fischeri also are known to take invertebrates including shrimps and crab
s. Reproduction is poorly known, with spawning
possibly occurring in estuaries and rivers.
Due to confusion with C. hippos, the species contribution to fisheries is also poorly understood. A combined total of 2233 to 10054 t
per year for C. hippos and C. fischeri was recorded from several Africa
n countries by the FAO in the 1995 to 2004 interval, indicating it is of moderate importance. Like the other crevalle jacks, the species is a strong gamefish and sought after by anglers in West Africa. Taken by lures or bait, the species is not considered a good table fish
, having coarse, tasteless flesh.
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 large marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
fish classified in the jack family, 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...
. It inhabits the subtropical waters of the east Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
, ranging along the Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
n coast from Mauritania
Mauritania
Mauritania is a country in the Maghreb and West Africa. It is bordered by the Atlantic Ocean in the west, by Western Sahara in the north, by Algeria in the northeast, by Mali in the east and southeast, and by Senegal in the southwest...
south at least to Moçamedes
Moçamedes
Moçâmedes may refer to:*Moçâmedes, was the name of a region and its chief city in the Portuguese Overseas Province of Angola, the present-day Namibe province and city, in South-Western Angola....
in southern Angola
Angola
Angola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...
, with the species historically present in the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
. It is an inshore species, known to occasionally penetrate estuaries, possibly to spawn
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
. The species is very similar to the crevalle jack
Crevalle jack
The crevalle jack, Caranx hippos is a common species of large marine fish classified within the jack family, Carangidae...
, Caranx hippos, and is separated by its extended 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 anal fin lobes as well as more detailed anatomical features including dorsal and anal fin ray counts. The fish is known to reach 127 cm in length and 20.9 kg
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...
in weight. The longfin crevalle jack is a predatory fish, taking small fish as its main prey. Due to longstanding confusion between C. fischeri and C. hippos, the importance of each species to African fisheries is poorly understood, with a known combined catch in this region of between 2,233 and 10,054 tonne
Tonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
s per year in 1995-2004. Like its close relatives, the species is considered a powerful gamefish and highly sought after, although their coarse flesh makes for relatively poor quality food
Fish (food)
Fish is a food consumed by many species, including humans. The word "fish" refers to both the animal and to the food prepared from it. Fish has been an important source of protein for humans throughout recorded history.-Terminology:...
.
Taxonomy and naming
The longfin crevalle jack is classified within the genus CaranxCaranx
Caranx is a genus of tropical to subtropical marine fish 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...
, 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
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...
, a group of percoid
Percoidei
Percoidei is one of eighteen suborders of bony fish in the order Perciformes. Many commercially harvested fish species are contained in this suborder, including the snappers, jacks, whitings, groupers, bass, perches and porgies.-Divisions:...
fishes in the order Perciformes
Perciformes
The Perciformes, also called the Percomorphi or Acanthopteri, is one of the largest orders of vertebrates, containing about 40% of all bony fish. Perciformes means perch-like. They belong to the class of ray-finned fish and comprise over 7,000 species found in almost all aquatic environments...
.
The species belongs to the "Caranx hippos complex" as defined by William Smith-Vaniz and Kent Carpenter, which includes C. fischeri, C. hippos and C. caninus
Pacific crevalle jack
The Pacific crevalle jack, Caranx caninus, is a species of large marine fish classified in the jack family Carangidae. The Pacific crevalle jack is distributed through the tropical waters of the eastern Pacific Ocean from California in the north to Peru in the south, including several offshore...
. The identity of the species was entangled with C. hippos until William Smith-Vaniz and Ken Carpenter described the species in full in 2007, anatomically setting it aside from C. hippos. The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
specimen is derived from a specimen collected in 1978 off Cameroon
Cameroon
Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...
, and was initially referred to C. hippos. The species has no synonym
Synonym
Synonyms are different words with almost identical or similar meanings. Words that are synonyms are said to be synonymous, and the state of being a synonym is called synonymy. The word comes from Ancient Greek syn and onoma . The words car and automobile are synonyms...
s due to its recent description, but the species has been misidentified as both C. hippos and C. carangus (now synonymous with C. hippos). The specific epithet is in reference to Dr. Walter Fischer, a former official of the FAO
Fão
Fão is a town in Esposende Municipality in Portugal....
who initiated the Species Identification and Data Program. The naming of the new species was presented at an IGCC and FAO meeting. The species common name as defined by Smith-Vaniz and Carpenter is 'longfin crevalle jack', referring to the extended fin lobes which separates the species from the crevalle jack.
Description
The longfin crevalle jack is large species, growing to a maximum recorded size of 53 cmCentimetre
A centimetre is a unit of length in the metric system, equal to one hundredth of a metre, which is the SI base unit of length. Centi is the SI prefix for a factor of . Hence a centimetre can be written as or — meaning or respectively...
as measured by Smith-Vaniz and Carpenter in their description. Discussion on the angling
Angling
Angling is a method of fishing by means of an "angle" . The hook is usually attached to a fishing line and the line is often attached to a fishing rod. Fishing rods are usually fitted with a fishing reel that functions as a mechanism for storing, retrieving and paying out the line. The hook itself...
merits of the species in the same publication indicate that the species grows significantly larger, recorded up to 127 cm by anglers mistaking it for C. hippos. It has a body profile similar to most of the large species in Caranx, possessing a strongly compressed approximately oblong
Rectangle
In Euclidean plane geometry, a rectangle is any quadrilateral with four right angles. The term "oblong" is occasionally used to refer to a non-square rectangle...
form. The dorsal profile is much more convex than the ventral profile, with the caudal peduncle quite slender. The dorsal fin
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...
is in two parts, the first consisting of 8 spines and the second of 1 spine followed by 21 to 24 soft rays. The dorsal and anal fin lobes are slightly elongated on the species, which distinguishes from the similar crevalle jack
Crevalle jack
The crevalle jack, Caranx hippos is a common species of large marine fish classified within the jack family, Carangidae...
. The anal fin consists of 2 detached spines anterior to the main bulk of the fin, which consists of 1 spine followed by 17 to 19 soft rays. 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...
is moderately arched anteriorly, with this section containing 50 to 73 scale
Scale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
s, while the straight section has 0 to 16 scales and 24 to 41 scute
Scute
A scute or scutum is a bony external plate or scale, as on the shell of a turtle, the skin of crocodilians, the feet of some birds or the anterior portion of the mesonotum in insects.-Properties:...
s. The breast is devoid of scales up to the origin of the pelvic fins and is separated from the base of the pectoral fins by a narrow band of scales. there are 20 to 25 gill raker
Gill raker
Gill rakers in fish are bony or cartilaginous processes that project from the branchial arch and are involved with filter feeding tiny prey. They are not to be confused with the gill filaments that compose the bony part of the gill. Rakers are usually present in two rows, projecting from both the...
s in total and 24 vertebrae.
The longfin crevalle jack is olive to greenish blue in colour dorsally, fading to pale and white ventrally. The dorsal fin dark brown to grey while the anal fin is brownish yellow, becoming white towards the lobe. The caudal fin is brown-yellow and the pelvic fins white. The species has a dark spot both on its opercle
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....
and lower pectoral fin rays.
Distribution and habitat
The longfin crevalle jack inhabits the subtropical waters of the east Atlantic OceanAtlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
, currently known to range from Mauritania
Mauritania
Mauritania is a country in the Maghreb and West Africa. It is bordered by the Atlantic Ocean in the west, by Western Sahara in the north, by Algeria in the northeast, by Mali in the east and southeast, and by Senegal in the southwest...
south to at least Moçamedes
Moçamedes
Moçâmedes may refer to:*Moçâmedes, was the name of a region and its chief city in the Portuguese Overseas Province of Angola, the present-day Namibe province and city, in South-Western Angola....
in southern Angola
Angola
Angola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...
. Publications describing historical fish specimens collected in the Mediterranean confirm Caranx fischeri was present in this region, although no recent specimens are known. The species appears to be able to travel long distances, with one adult collected from 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...
in the mid-Atlantic.
The longfin crevalle jack appears to be primarily an inshore species based the limited data available, although captures such as those in the Ascension Island indicate the species may live pelagically. In the inshore environment they are known from reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s, as well as estuarine environments, possibly penetrating the upper reaches of river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
s.
Biology and fishery
The specifics of the longfin crevalle jack's biology are not known due its recent description and previous confusion with C. hippos. It is clear that all species of crevalle jack are powerful predators, taking a variety of small, schooling fish species including herringsClupeidae
Clupeidae is the family of the herrings, shads, sardines, hilsa and menhadens. It includes many of the most important food fishes in the world.-Description and biology:...
, other carangids and porgies of the family Sparidae. Small jacks, probably including C. fischeri also are known to take invertebrates including shrimps and crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s. Reproduction is poorly known, with spawning
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
possibly occurring in estuaries and rivers.
Due to confusion with C. hippos, the species contribution to fisheries is also poorly understood. A combined total of 2233 to 10054 t
Tonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
per year for C. hippos and C. fischeri was recorded from several Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
n countries by the FAO in the 1995 to 2004 interval, indicating it is of moderate importance. Like the other crevalle jacks, the species is a strong gamefish and sought after by anglers in West Africa. Taken by lures or bait, the species is not considered a good table fish
Fish (food)
Fish is a food consumed by many species, including humans. The word "fish" refers to both the animal and to the food prepared from it. Fish has been an important source of protein for humans throughout recorded history.-Terminology:...
, having coarse, tasteless flesh.