Bluespotted trevally
Encyclopedia
The bluespotted trevally, Caranx bucculentus (also known as the wide-mouthed trevally), is a species
of moderately large marine
fish
in the jack family Carangidae
. The bluespotted trevally is distributed through the tropical east Indian
and west Pacific Ocean
s, ranging from Taiwan
in the north to Australia
in the south. It is an inshore species
, found in sandy, muddy and seagrass
environments, often in large bay
s. The bluespotted trevally is distinguished by dark blue spots on its upper body, as well as a number of more detailed anatomical features. It is a benthopelagic predator, taking a variety of crustacean
s including crab
s and prawn
s as a juvenile, before shifting to a more fish dominated diet as an adult. It is one of the most common predators in the Gulf of Carpentaria
of northern Australia and is considered the most important predator of commercially important prawn species. Sexual maturity
is reached at 110 mm in length and 1 year of age, with spawning
occurring year round with a peak in spring. Growth is estimated to be 82.2 mm per year for both sexes, reaching a maximum known length of 66 cm. Bluespotted trevally are commonly taken as bycatch in prawn fisheries, however are of little commercial value and often discarded. They are occasionally taken by angler
s on lures and baits, but are considered mediocre table fare
.
, 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 was first scientifically described by the Australian zoologists Haynes Gibbs Alleyne and Sir William John Macleay
based on a specimen collected off Cape Grenville
, Queensland
, which was later designated to be the holotype
. They named the species Caranx bucculentus, with the specific epithet meaning 'with full cheeks' in Latin, referring to the species wide mouth gape. In the original volume of Proceedings of the Linnean Society of New South Wales
in which the species was described, the specific name is spelled as bucculantus in the legend, but is considered to be a typographical error
and ignored. The species placement in Caranx has never been challenged and there have been no attempts to independently rename the species, making it one of the few members of Caranx to have no synonyms. The commonly used
name of 'bluespotted trevally' is in reference to the fishes' body markings with 'wide-mouthed trevally' also infrequently used.
form with the dorsal profile, particularly anteriorly, much more convex than the ventral profile. The dorsal fin
is in two distinct sections, the first consisting of 8 spines while the second has 1 spine and 18 or 19 soft rays. The anal fin consists of 2 detached spines anteriorly followed by 1 spine and 15 to 17 soft rays, while the pelvic fin has 1 spine followed by 18 soft rays. The species lateral line
is very strongly curved over a short length, becoming straight before the origin of the second dorsal fin, with this straight section over 2.5 times the length of the curved section. The curved section contain 40 to 50 scales
while the straight section contains no scales, but 33 to 39 strong scute
s. The breast is naked ventrally, with this area extending to behind the origin of the pelvic fins and diagonally to the base of pectoral fins. The eyes have a moderately well developed posterior adipose eyelid which usually extends to the posterior edge of the pupil. The upper jaw
contains an outer row of strong canines
and an inner band of villiform teeth, while the lower jaw has only a single band of conical teeth. There are 26 to 31 gill rakers in total and 24 vertebrae in the species.
The bluespotted trevally is a pale olive green above, fading to a more silvery white below, with adults having numerous small blue spots on the upper half of their body. The upper end of the opercle
has a large dark spot, with a black spot also present at the upper base of the pectoral fins. All the fin
s are yellow green.
-West Pacific Ocean
, and is restricted to a smaller range than most of its relatives. The species range extends from the waters of the South China Sea
around Taiwan
and Borneo
south through eastern Indonesia
and the Arafura Sea
around Papua New Guinea
. The species is commonly found off northern Australia
, especially the Gulf of Carpentaria
, but is occasionally seen as far south as Gladstone, Queensland
.
The bluespotted trevally is an inshore fish, generally inhabiting coastal waters throughout its range. The species is known to inhabit shallow bay
s over sand
, mud
and rarely seagrass
bottoms as well as slightly deeper waters in bays. Extensive sampling across the Gulf of Carpentaria indicates the maximum biomass
for the species occurs at around 28.1 m depth, indicating the species preferentially inhabits substrate of this depth.
has been conducted on the bluespotted trevally in comparison to most other Indo-Pacific carangids, with this being partly due to the discovery of its abundance and importance in northern Australian shallow water ecosystem
s. It is one of the top ten most abundant secondary consumers in the system and the most important predator of commercially important prawn species. Successive sampling periods over a period between 1986 and 1991 found there was no systematic seasonal variations in the species abundance, although there were interannual variations in numbers. The species also appears to undergo diel vertical migration
s as evidenced by markedly decreased catches in demersal night trawls, possibly in response to prey movement.
Bluespotted trevally are predatory fish, consuming a range of crustacean
s and fish. Studies in the Gulf of Carpentaria and in particular, Albatross Bay, indicate the species is most common over known prawn
grounds. There is a shift in diet with age, with young fish less than 275 mm in length taking penaeids, brachyurans, other crustaceans, echinoderm
s and molluscs while larger fish take mostly small fish. The smaller trevally tend to forage during the day, taking species of small non-commercial species of prawn, while the larger fish took larger, commercially important species at night. Experimental studies indicate that the species has low success foraging
in seagrass beds and over soft strata where penaeids burrow during the day, but increase efficiency during the night when the prawns emerge to forage. There appears to be little seasonal variation in diet.
Bluespotted trevally reach sexual maturity
at around 110 mm in length, usually after their first year of life. This is much earlier than other members of the genus which attain similar lengths and reach maturity in the second or third years of life. The species spawns
year round in the Gulf of Carpentaria with a peak in spring, with between 18,000 and 650,000 eggs released during spawning. The bluespotted trevally grows at a rate of around 82.2 mm per year. Intensive feeding experiments indicate the species can increase its weight by 3.7% and 2.7% of its body weight per day when fed prawns and pilchards, respectively.
based around the species. They are taken by trawls and hook and line methods throughout their range, but form a considerable proportion of some prawn trawler bycatches. Despite this, they are generally considered of no worth due to their mediocre reputation as table fish, as well as the possibility of ciguatera
poisoning larger specimens.
Bluespotted trevally are occasionally caught by recreational fishermen
on various baits and lures and are considered to a good sport fish, but tend to be overshadowed by giant trevally
and bluefin trevally
in reputation.
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 moderately 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
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...
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...
. The bluespotted trevally is distributed through the tropical east Indian
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...
and west Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
s, ranging from Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
in the north to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
in the south. It is an inshore species
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...
, found in sandy, muddy and seagrass
Seagrass
Seagrasses are flowering plants from one of four plant families , all in the order Alismatales , which grow in marine, fully saline environments.-Ecology:...
environments, often in large bay
Bay
A bay is an area of water mostly surrounded by land. Bays generally have calmer waters than the surrounding sea, due to the surrounding land blocking some waves and often reducing winds. Bays also exist as an inlet in a lake or pond. A large bay may be called a gulf, a sea, a sound, or a bight...
s. The bluespotted trevally is distinguished by dark blue spots on its upper body, as well as a number of more detailed anatomical features. It is a benthopelagic predator, taking a variety of crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s including 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 and prawn
Prawn
Prawns are decapod crustaceans of the sub-order Dendrobranchiata. There are 540 extant species, in seven families, and a fossil record extending back to the Devonian...
s as a juvenile, before shifting to a more fish dominated diet as an adult. It is one of the most common predators in the Gulf of Carpentaria
Gulf of Carpentaria
The Gulf of Carpentaria is a large, shallow sea enclosed on three sides by northern Australia and bounded on the north by the Arafura Sea...
of northern Australia and is considered the most important predator of commercially important prawn species. Sexual maturity
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
is reached at 110 mm in length and 1 year of age, 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...
occurring year round with a peak in spring. Growth is estimated to be 82.2 mm per year for both sexes, reaching a maximum known length of 66 cm. Bluespotted trevally are commonly taken as bycatch in prawn fisheries, however are of little commercial value and often discarded. They are occasionally taken by angler
Anglerfish
Anglerfishes are members of the teleost order Lophiiformes . They are bony fishes named for their characteristic mode of predation, wherein a fleshy growth from the fish's head acts as a lure; this is considered analogous to angling.Some anglerfishes are pelagic , while others are benthic...
s on lures and baits, but are considered mediocre table fare
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 bluespotted trevally 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 was first scientifically described by the Australian zoologists Haynes Gibbs Alleyne and Sir William John Macleay
William John Macleay
Sir William John Macleay . was an Australian politician, zoologist and naturalist.-Early life:Macleay was born at Wick, Caithness, Scotland, second son of Kenneth Macleay of Keiss and his wife Barbara, née Horne...
based on a specimen collected off Cape Grenville
Cape Grenville
Cape Grenville , is a small, east-facing promontory along the Queensland, Australia coast of Cape York Peninsula. It lies between Shelburne Bay to the north and Temple Bay to the south. The nearest significant settlement is Weipa, Queensland, along the western coast of Cape York.The northern part...
, Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, which was later designated to be 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...
. They named the species Caranx bucculentus, with the specific epithet meaning 'with full cheeks' in Latin, referring to the species wide mouth gape. In the original volume of Proceedings of the Linnean Society of New South Wales
Linnean Society of New South Wales
The Linnean Society of New South Wales promotes the Cultivation and Study of the Science of Natural History in all its Branches and was founded in Sydney, New South Wales in 1874 and incorporated in 1884. It succeeded the Entomological Society of New South Wales, founded in 1862 and folded in...
in which the species was described, the specific name is spelled as bucculantus in the legend, but is considered to be a typographical error
Typographical error
A typographical error is a mistake made in, originally, the manual type-setting of printed material, or more recently, the typing process. The term includes errors due to mechanical failure or slips of the hand or finger, but usually excludes errors of ignorance, such as spelling errors...
and ignored. The species placement in Caranx has never been challenged and there have been no attempts to independently rename the species, making it one of the few members of Caranx to have no synonyms. The commonly used
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
name of 'bluespotted trevally' is in reference to the fishes' body markings with 'wide-mouthed trevally' also infrequently used.
Description
The bluespotted trevally is a moderately large fish, growing to a known maximum length of 66 cm. It has a body shape characteristic of many of the larger species of Caranx, possessing a strongly compressed oblongRectangle
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 with the dorsal profile, particularly anteriorly, much more convex than the ventral profile. 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 distinct sections, the first consisting of 8 spines while the second has 1 spine and 18 or 19 soft rays. The anal fin consists of 2 detached spines anteriorly followed by 1 spine and 15 to 17 soft rays, while the pelvic fin has 1 spine followed by 18 soft rays. The species 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 very strongly curved over a short length, becoming straight before the origin of the second dorsal fin, with this straight section over 2.5 times the length of the curved section. The curved section contain 40 to 50 scales
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...
while the straight section contains no scales, but 33 to 39 strong 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 naked ventrally, with this area extending to behind the origin of the pelvic fins and diagonally to the base of pectoral fins. The eyes have a moderately well developed posterior adipose eyelid which usually extends to the posterior edge of the pupil. The upper jaw
Jaw
The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...
contains an outer row of strong canines
Canine tooth
In mammalian oral anatomy, the canine teeth, also called cuspids, dogteeth, fangs, or eye teeth, are relatively long, pointed teeth...
and an inner band of villiform teeth, while the lower jaw has only a single band of conical teeth. There are 26 to 31 gill rakers in total and 24 vertebrae in the species.
The bluespotted trevally is a pale olive green above, fading to a more silvery white below, with adults having numerous small blue spots on the upper half of their body. The upper end of the 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....
has a large dark spot, with a black spot also present at the upper base of the pectoral fins. All the fin
Fin
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...
s are yellow green.
Distribution and habitat
The bluespotted trevally inhabits the tropical waters of the East IndianIndian 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...
-West Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
, and is restricted to a smaller range than most of its relatives. The species range extends from the waters of the South China Sea
South China Sea
The South China Sea is a marginal sea that is part of the Pacific Ocean, encompassing an area from the Singapore and Malacca Straits to the Strait of Taiwan of around...
around Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
and Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
south through eastern Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
and the Arafura Sea
Arafura Sea
The Arafura Sea lies west of the Pacific Ocean overlying the continental shelf between Australia and New Guinea.-Geography:The Arafura Sea is bordered by Torres Strait and through that the Coral Sea to the east, the Gulf of Carpentaria to the south, the Timor Sea to the west and the Banda and Ceram...
around Papua New Guinea
Papua New Guinea
Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...
. The species is commonly found off northern Australia
Northern Australia
The term northern Australia is generally known to include two State and Territories, being Queensland and the Northern Territory . The part of Western Australia north of latitude 26° south—a definition widely used in law and State government policy—is also usually included...
, especially the Gulf of Carpentaria
Gulf of Carpentaria
The Gulf of Carpentaria is a large, shallow sea enclosed on three sides by northern Australia and bounded on the north by the Arafura Sea...
, but is occasionally seen as far south as Gladstone, Queensland
Gladstone, Queensland
- Education :Gladstone has several primary schools, three high schools, and one university campus, Central Queensland University. It is also home to CQIT Gladstone Campus.- Recreation :...
.
The bluespotted trevally is an inshore fish, generally inhabiting coastal waters throughout its range. The species is known to inhabit shallow bay
Bay
A bay is an area of water mostly surrounded by land. Bays generally have calmer waters than the surrounding sea, due to the surrounding land blocking some waves and often reducing winds. Bays also exist as an inlet in a lake or pond. A large bay may be called a gulf, a sea, a sound, or a bight...
s over sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
, mud
Mud
Mud is a mixture of water and some combination of soil, silt, and clay. Ancient mud deposits harden over geological time to form sedimentary rock such as shale or mudstone . When geological deposits of mud are formed in estuaries the resultant layers are termed bay muds...
and rarely seagrass
Seagrass
Seagrasses are flowering plants from one of four plant families , all in the order Alismatales , which grow in marine, fully saline environments.-Ecology:...
bottoms as well as slightly deeper waters in bays. Extensive sampling across the Gulf of Carpentaria indicates the maximum biomass
Biomass
Biomass, as a renewable energy source, is biological material from living, or recently living organisms. As an energy source, biomass can either be used directly, or converted into other energy products such as biofuel....
for the species occurs at around 28.1 m depth, indicating the species preferentially inhabits substrate of this depth.
Biology
Considerable researchResearch
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...
has been conducted on the bluespotted trevally in comparison to most other Indo-Pacific carangids, with this being partly due to the discovery of its abundance and importance in northern Australian shallow water ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
s. It is one of the top ten most abundant secondary consumers in the system and the most important predator of commercially important prawn species. Successive sampling periods over a period between 1986 and 1991 found there was no systematic seasonal variations in the species abundance, although there were interannual variations in numbers. The species also appears to undergo diel vertical migration
Diel vertical migration
Diel vertical migration, also known as diurnal vertical migration, is a pattern of movement that some organisms living in the ocean and in lakes undertake each day. Usually organisms move up to the epipelagic zone at night and return to the mesopelagic zone of the oceans or to the hypolimnion zone...
s as evidenced by markedly decreased catches in demersal night trawls, possibly in response to prey movement.
Bluespotted trevally are predatory fish, consuming a range of crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s and fish. Studies in the Gulf of Carpentaria and in particular, Albatross Bay, indicate the species is most common over known prawn
Prawn
Prawns are decapod crustaceans of the sub-order Dendrobranchiata. There are 540 extant species, in seven families, and a fossil record extending back to the Devonian...
grounds. There is a shift in diet with age, with young fish less than 275 mm in length taking penaeids, brachyurans, other crustaceans, echinoderm
Echinoderm
Echinoderms are a phylum of marine animals. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone....
s and molluscs while larger fish take mostly small fish. The smaller trevally tend to forage during the day, taking species of small non-commercial species of prawn, while the larger fish took larger, commercially important species at night. Experimental studies indicate that the species has low success foraging
Foraging
- Definitions and significance of foraging behavior :Foraging is the act of searching for and exploiting food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce...
in seagrass beds and over soft strata where penaeids burrow during the day, but increase efficiency during the night when the prawns emerge to forage. There appears to be little seasonal variation in diet.
Bluespotted trevally reach sexual maturity
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
at around 110 mm in length, usually after their first year of life. This is much earlier than other members of the genus which attain similar lengths and reach maturity in the second or third years of life. The species spawns
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...
year round in the Gulf of Carpentaria with a peak in spring, with between 18,000 and 650,000 eggs released during spawning. The bluespotted trevally grows at a rate of around 82.2 mm per year. Intensive feeding experiments indicate the species can increase its weight by 3.7% and 2.7% of its body weight per day when fed prawns and pilchards, respectively.
Relationship to humans
Despite the large populations of bluespotted trevally, particularly in northern Australia, there is no major fisheryFishery
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...
based around the species. They are taken by trawls and hook and line methods throughout their range, but form a considerable proportion of some prawn trawler bycatches. Despite this, they are generally considered of no worth due to their mediocre reputation as table fish, as well as the possibility of ciguatera
Ciguatera
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...
poisoning larger specimens.
Bluespotted trevally are occasionally caught by recreational fishermen
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...
on various baits and lures and are considered to a good sport fish, but tend to be overshadowed by giant trevally
Giant trevally
The giant trevally, Caranx ignobilis , is a species of large marine fish classified in the jack family, Carangidae...
and bluefin trevally
Bluefin trevally
The bluefin trevally, Caranx melampygus , is a species of large, widely distributed marine fish classified in the jack family, Carangidae...
in reputation.