Rainbow runner
Encyclopedia
The rainbow runner , also known as the rainbow yellowtail, Spanish jack and Hawaiian salmon, is a common species
of pelagic marine
fish
of the jack family, Carangidae
. The species is widespread throughout the tropical and subtropical waters of the world, inhabiting both coastal as well as far offshore areas. The species is the only member of the genus Elagatis, which was created 15 years after its initial description, and is closely related to the amberjack
s. The rainbow runner is easily distinguished by its body shape, and the brilliant colouration which gives the fish its name. It is a fast swimming predator, taking small fish, cephalopod
s and a wide variety of plankton
ic crustaceans. The species reaches sexual maturity
at around 60 cm (23.6 in), and spawning
takes place at different times, with some populations spawning year round, while others only spawn at certain times of the year. The species is a well known game fish
, taken by a variety of fishing methods and is a well rated table fish. Large amounts of the species are taken as bycatch in tuna
and shark
fishing operations and marketed.
genus Elagatis, which is one of thirty genera in the jack family, Carangidae
. The Carangidae are Perciform fishes in the suborder Percoidei
. The species was first scientifically described in 1825 by French
zoologists Jean René Constant Quoy
and Joseph Paul Gaimard
based on the type specimen collected from the Indian Ocean, somewhere in the Malay Archipelago
. They named the species Seriola
bipinnulata, believing the species was related to the amberjacks. This was later revised to the genus Seriolichthys by Bleeker before it was concluded the species warranted a new genus. The genus Micropteryx was initially created, but was already in use in the Lepidoptera
. In 1840, Edward Bennett
was recognized as the author of the genus Elagatis, taken from a name published in a whaling voyage memoir, which he used in combination with the species name of bipinnulatus, which was deemed to be incorrect and the original spelling of bipinnulata reinstalled. Phylogenetically, the species is most closely related to the amberjack genus, Seriola, being the most basal member identified of the carangid subfamily Naucratini. This has been determined by the sequencing of the mitochondrial cytochrome b
genome, as well as older morphological studies.
The species wide range has led to a wide array of local common name
s, with the most common English
name being 'rainbow runner' in reference to its colouring. Other names frequently applied include rainbow yellowtail, Hawaiian salmon, Salmon (incorrectly), Spanish Jack, as well as over twenty other names in various languages.
The rainbow runner has a body that is atypical of the jack family, which generally have deep, compressed bodies. The rainbow runner has a subcylindrical, elongated to almost fusiform body, with a long pointed head and snout and a tapering rear end before the caudal fin emerges. The eye is relatively small and the teeth are arranged on jaws in villiform bands, with minute teeth also present on the roof of the mouth and tongue. The fish has two dorsal fin
s, although the posterior rays of the long second fin have separated into a finlet. The first dorsal consists of 6 spines, the second of a single spine and 25 to 30 soft rays, with the last two as a separate finlet. Approximately 4% of rainbow runner have only five spines in the first dorsal fin, and are apparently born without them.
The anal fin consists of one spine detached from the fin anteriorally, while the main fin has a single spine and 18 to 22 soft rays, with the last two detached to form a finlet like the dorsal fin. The dorsal and anal fins are quite low, and the dorsal fin is much longer than the anal. The pectoral fin is small for a carangid, about the length of the pelvic fin and is non-falcate with 20 rays. The pelvic fin consists of one spine and five branched soft rays. The caudal fin is also highly diagnostic, being deeply forked and consisting of 17 caudal rays, 9 dorsally and 8 ventrally. The lateral line
has a slight anterior arch and there are no scute
s present on the line, but possesses about 100 scales. The scales covering the body and parts of the operculum
, cheek, pectoral fins, pelvic fins, and caudal fins are ctenoid in shape. The species has 24 vertebrae.
The colour of the fish is possibly the easiest way to identify the rainbow runner, with the name taken from the species striking colours. The upper body is a dark olive blue to green and fading to white underneath. There are two narrow light blue to bluish white stripes running longitudinal
ly along the sides, with a broader olive to yellow stripe between them. The maximum length of the species is somewhat contentious, with most sources giving a known maximum length of between 107 cm (42.1 in) and 120 cm (47.2 in) cm, while one source asserts the species reaches 180 cm (70.9 in) in length. The maximum known weight is confidently known to be 46.2 kg, as recorded by the IGFA
.
and Bermuda
to north eastern Brazil
, including the northern and southern Gulf of Mexico
, the Bahamas and the Greater and Lesser Antilles
, extending east to at least the Azores
.
The species is widespread throughout the Pacific Ocean
, but appears to be slightly less abundant in parts of the Indian Ocean
, and rare or absent in the Persian Gulf
.
The species is an occasional visitor to the Mediterranean Sea
, generally as a Lessepsian immigrant through the Suez Canal
, but has not taken up permanent residence like other species. The species also inhabits the nearby Canary Islands
, possibly entering the Mediterranean from the east also.
The species is primarily pelagic, inhabiting the upper 164 m of the water column,
sometimes close to land over rock and coral reef
systems, as well as far offshore. The species occasionally comes quite close to shore, known to inhabits lagoons for short periods, and juveniles have even been reported in a Taiwanese estuary
system. Rainbow runner, like other carangids such as Yellowtail kingfish are easily attracted to special Fish Attracting Devices (FAD's), floating buoy type structures. The species has been shown to occupy a water zone outside of the FAD up to 12 m deep and 10 m wide, treating it as if it were a stationary object.
The species often forms schools of variable sizes ranging from a few individuals to several hundred. The species is also highly migratory
, and biochemical studies on the species have shown that the muscles contain unusually high levels of a fatty acid
called DHA
. The reason for this is probably that the muscle is also low in lipids due to accumulation of these in other organs. Other migratory fishes such as tuna also have this adaptation, suggesting it is a convergent
trait.
s and pelagic or planktonic crustacean
s including, shrimp
s and crab
s. It has been demonstrated that the species shows selectivity of its prey, with fish in the Pacific Ocean taking higher amounts of Decapterus macarellus, a small fish, than any other prey available. It was also found in the same study that rainbow runner may increase the swimming and prey searching abilities rapidly with their growth, becoming more efficient at finding their preferred prey items. Rainbow runner are also one of a number of pelagic fish
es that prey on open-ocean species of sea-skaters (Halobates
spp.), a type of insect which rest on the surface of the ocean.
Rainbow runner themselves are important prey items for a number of larger species, with positively identified predators being Fraser's Dolphin
(Lagenodelphis hosei), and a number of seabirds of the family Laridae.
is only confidently known for the female of the species, being around 600 mm in fork length, although the male has been estimated to reach maturity at between 600 and 650 mm.
In the Atlantic, the species is known to spawn from spring through to early autumn,
although fish living in waters greater than 27 degrees Celsius spawn year round. However, even when year-round spawning occurs, there are seasonal peaks, with fish in the Western Pacific Ocean showing these peaks in May and in December – January.
The fish is oviparous, producing pelagic eggs and larva
e. The larval stages have been studied in detail by Richards (2006), with the diagnostic features of the larvae include a supraoccupital crest and distinctive patterns of pigment
and melanophores. The growth of the fish has also been studied, with the size of fish at 1, 2, 3, 4 and 5 years ages are estimated to be 30, 46, 59, 69 and 77 cm in length respectively. The migration pattern of juveniles is poorly known, with only a migration from equatorial spawning grounds to the coasts of Japan
recorded, often floating in the currents under large mats of Sargassum
.
Rainbow runner are not a major commercial species like tuna or herring
, but are taken in large quantities as bycatch. Their flesh is said to be of fair to excellent standard, depending on personal preferences, but generally fetch a low price at markets because they are relatively unknown. Archaeological evidence from the Kapingamarangi and Nukuoro Atolls in the Caroline Islands
of Micronesia
suggests the prehistoric people of these islands caught large amounts of rainbow runner as food, thought to have been captured by 'trolling' lure hooks from canoes.
, however, large amounts of the species often turn up as bycatch from tuna and shark fisheries, with the bycatch from the West Indian Tuna Fishery alone totaling 720–1877 t between 1985–94. In recent years this figure has increased, with global catches as estimated by the FAO peaking at 18,940 t per year in 1998 before declining to around 15,000 t per year in 2000/01. This bycatch is nearly always kept and sold at market, either fresh, salted or frozen.
The methods used to take most rainbow runner are purse seines, as well as hook and line techniques and other native fishing methods. At least one case of ciguatera
poisoning has been reported from this species on the Virgin Islands
.
for rainbow runner in parts of the world. Often they are taken while trolling for other species such as tuna and mackerel, but are often targeted inshore by anglers on the west coast of the Americas using surface 'popper' style lures. The fish are caught on a wide variety of lures and baits, with deep diving lures, surface lures and even saltwater flies used to good measure. The species takes a wide variety of baits including live and cut fish, squid
, octopus
, and probably other crustaceans resembling their natural food. They are renowned as gamefish, especially at larger sizes. The species themselves are also commonly used as bait, either as live bait or dead bait rigged to be troll
ed behind game boats for larger species such as billfish
and tuna
.
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 pelagic marine
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
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 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 species is widespread throughout the tropical and subtropical waters of the world, inhabiting both coastal as well as far offshore areas. The species is the only member of the genus Elagatis, which was created 15 years after its initial description, and is closely related to the amberjack
Amberjack
Amberjack refers to 3 species of Atlantic fish of the Carangidae family , which includes the jacks and the pompanos.Greater amberjacks, Seriola dumerili, are the largest of the jacks. They usually have dark stripes extending from nose to in front of their dorsal fins...
s. The rainbow runner is easily distinguished by its body shape, and the brilliant colouration which gives the fish its name. It is a fast swimming predator, taking small fish, cephalopod
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
s and a wide variety of plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
ic crustaceans. The species reaches 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 60 cm (23.6 in), and 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...
takes place at different times, with some populations spawning year round, while others only spawn at certain times of the year. The species is a well known game fish
Game fish
Game fish are fish pursued for sport by recreational anglers. They can be freshwater or marine fish. Game fish can be eaten after being caught, though increasingly anglers practise catch and release to improve fish populations. Some game fish are also targeted commercially, particularly...
, taken by a variety of fishing methods and is a well rated table fish. Large amounts of the species are taken as bycatch in tuna
Tuna
Tuna is a salt water fish from the family Scombridae, mostly in the genus Thunnus. Tuna are fast swimmers, and some species are capable of speeds of . Unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red coloration derives from myoglobin, an...
and shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....
fishing operations and marketed.
Taxonomy and naming
The rainbow runner is the only species in the monotypicMonotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus Elagatis, which is one of thirty genera 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 Carangidae are Perciform fishes in the suborder Percoidei
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:...
. The species was first scientifically described in 1825 by French
French people
The French are a nation that share a common French culture and speak the French language as a mother tongue. Historically, the French population are descended from peoples of Celtic, Latin and Germanic origin, and are today a mixture of several ethnic groups...
zoologists Jean René Constant Quoy
Jean René Constant Quoy
Jean René Constant Quoy was a French zoologist.Along with Joseph Paul Gaimard he served as naturalist aboard La Coquille under Louis Isidore Duperrey during its circumnavigation of the globe , and the Astrolabe under the command of Jules Dumont d'Urville...
and Joseph Paul Gaimard
Joseph Paul Gaimard
Joseph Paul Gaimard was a French naval surgeon and naturalist.Along with Jean René Constant Quoy he served as naturalist on the ships L'Uranie under Louis de Freycinet 1817-1820, and L'Astrolabe under Jules Dumont d'Urville 1826-1829...
based on the type specimen collected from the Indian Ocean, somewhere in the Malay Archipelago
Malay Archipelago
The Malay Archipelago refers to the archipelago between mainland Southeastern Asia and Australia. The name was derived from the anachronistic concept of a Malay race....
. They named the species Seriola
Seriola
Seriola is a genus of bony fish, commonly known as amberjacks. Nine species are currently recognized, although these were formerly split into many more...
bipinnulata, believing the species was related to the amberjacks. This was later revised to the genus Seriolichthys by Bleeker before it was concluded the species warranted a new genus. The genus Micropteryx was initially created, but was already in use in the Lepidoptera
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
. In 1840, Edward Bennett
Edward Turner Bennett
Edward Turner Bennett was an English zoologist and writer. He was the elder brother of the botanist John Joseph Bennett. Bennett was born at Hackney and practiced as a surgeon, but his chief pursuit was always zoology...
was recognized as the author of the genus Elagatis, taken from a name published in a whaling voyage memoir, which he used in combination with the species name of bipinnulatus, which was deemed to be incorrect and the original spelling of bipinnulata reinstalled. Phylogenetically, the species is most closely related to the amberjack genus, Seriola, being the most basal member identified of the carangid subfamily Naucratini. This has been determined by the sequencing of the mitochondrial cytochrome b
Cytochrome b
Cytochrome b/b6 is the main subunit of transmembrane cytochrome bc1 and b6f complexes. In addition, it commonly refers to a region of mtDNA used for population genetics and phylogenetics.- Function :...
genome, as well as older morphological studies.
The species wide range has led to a wide array of local common name
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...
s, with the most common English
English language
English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...
name being 'rainbow runner' in reference to its colouring. Other names frequently applied include rainbow yellowtail, Hawaiian salmon, Salmon (incorrectly), Spanish Jack, as well as over twenty other names in various languages.
Description
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...
s, although the posterior rays of the long second fin have separated into a finlet. The first dorsal consists of 6 spines, the second of a single spine and 25 to 30 soft rays, with the last two as a separate finlet. Approximately 4% of rainbow runner have only five spines in the first dorsal fin, and are apparently born without them.
The anal fin consists of one spine detached from the fin anteriorally, while the main fin has a single spine and 18 to 22 soft rays, with the last two detached to form a finlet like the dorsal fin. The dorsal and anal fins are quite low, and the dorsal fin is much longer than the anal. The pectoral fin is small for a carangid, about the length of the pelvic fin and is non-falcate with 20 rays. The pelvic fin consists of one spine and five branched soft rays. The caudal fin is also highly diagnostic, being deeply forked and consisting of 17 caudal rays, 9 dorsally and 8 ventrally. 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...
has a slight anterior arch and there are no 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 present on the line, but possesses about 100 scales. The scales covering the body and parts 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....
, cheek, pectoral fins, pelvic fins, and caudal fins are ctenoid in shape. The species has 24 vertebrae.
The colour of the fish is possibly the easiest way to identify the rainbow runner, with the name taken from the species striking colours. The upper body is a dark olive blue to green and fading to white underneath. There are two narrow light blue to bluish white stripes running longitudinal
Longitude
Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....
ly along the sides, with a broader olive to yellow stripe between them. The maximum length of the species is somewhat contentious, with most sources giving a known maximum length of between 107 cm (42.1 in) and 120 cm (47.2 in) cm, while one source asserts the species reaches 180 cm (70.9 in) in length. The maximum known weight is confidently known to be 46.2 kg, as recorded by the IGFA
International Game Fish Association
The International Game Fish Association is the leading authority on angling pursuits and the keeper of the most current World Record fishing catches by fish categories. Fishermen who are sport fishers are careful to follow their stringent rules for fair play and line requirements in order to...
.
Distribution and habitat
The rainbow runner has a circumtropical distribution, inhabiting tropical and some subtropical waters worldwide. In the Western Atlantic, the species occurs from MassachusettsMassachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
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...
to north eastern Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, including the northern and southern 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...
, the Bahamas and the Greater and Lesser Antilles
Antilles
The Antilles islands form the greater part of the West Indies in the Caribbean Sea. The Antilles are divided into two major groups: the "Greater Antilles" to the north and west, including the larger islands of Cuba, Jamaica, Hispaniola , and Puerto Rico; and the smaller "Lesser Antilles" on the...
, extending east to at least the Azores
Azores
The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...
.
The species is widespread throughout the 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...
, but appears to be slightly less abundant in parts of 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...
, and rare or absent in the Persian Gulf
Persian Gulf
The Persian Gulf, in Southwest Asia, is an extension of the Indian Ocean located between Iran and the Arabian Peninsula.The Persian Gulf was the focus of the 1980–1988 Iran-Iraq War, in which each side attacked the other's oil tankers...
.
The species is an occasional visitor to 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...
, generally as a Lessepsian immigrant through the Suez Canal
Suez Canal
The Suez Canal , also known by the nickname "The Highway to India", is an artificial sea-level waterway in Egypt, connecting the Mediterranean Sea and the Red Sea. Opened in November 1869 after 10 years of construction work, it allows water transportation between Europe and Asia without navigation...
, but has not taken up permanent residence like other species. The species also inhabits the nearby Canary Islands
Canary Islands
The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...
, possibly entering the Mediterranean from the east also.
The species is primarily pelagic, inhabiting the upper 164 m of the water column,
sometimes close to land over rock and coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
systems, as well as far offshore. The species occasionally comes quite close to shore, known to inhabits lagoons for short periods, and juveniles have even been reported in a Taiwanese estuary
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
system. Rainbow runner, like other carangids such as Yellowtail kingfish are easily attracted to special Fish Attracting Devices (FAD's), floating buoy type structures. The species has been shown to occupy a water zone outside of the FAD up to 12 m deep and 10 m wide, treating it as if it were a stationary object.
Biology
Fish migration
Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres...
, and biochemical studies on the species have shown that the muscles contain unusually high levels of a fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
called DHA
Docosahexaenoic acid
Docosahexaenoic acid is an omega-3 fatty acid that is a primary structural component of the human brain and retina. In chemical structure, DHA is a carboxylic acid with a 22-carbon chain and six cis double bonds; the first double bond is located at the third carbon from the omega end...
. The reason for this is probably that the muscle is also low in lipids due to accumulation of these in other organs. Other migratory fishes such as tuna also have this adaptation, suggesting it is a convergent
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
trait.
Diet
Rainbow runner are fast swimming carnivores that take a wide range of prey including a wide variety of small fishes, cephalopodCephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
s and pelagic or planktonic 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, shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
s 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. It has been demonstrated that the species shows selectivity of its prey, with fish in the Pacific Ocean taking higher amounts of Decapterus macarellus, a small fish, than any other prey available. It was also found in the same study that rainbow runner may increase the swimming and prey searching abilities rapidly with their growth, becoming more efficient at finding their preferred prey items. Rainbow runner are also one of a number of pelagic fish
Pelagic fish
Pelagic fish live near the surface or in the water column of coastal, ocean and lake waters, but not on the bottom of the sea or the lake. They can be contrasted with demersal fish, which do live on or near the bottom, and reef fish which are associated with coral reefs.The marine pelagic...
es that prey on open-ocean species of sea-skaters (Halobates
Halobates
Halobates or sea skaters are a genus with over 40 species of water striders. While many are coastal, about five of these are able to survive and stand on the surface of the open ocean, a habitat containing very few insect species. They are predators, coastal species feeding mainly on fallen...
spp.), a type of insect which rest on the surface of the ocean.
Rainbow runner themselves are important prey items for a number of larger species, with positively identified predators being Fraser's Dolphin
Fraser's Dolphin
Fraser's Dolphin or Sarawak Dolphin is a cetacean in the family Delphinidae found in deep waters in the Pacific Ocean and to a lesser extent in the Indian and Atlantic Oceans.-Taxonomy:...
(Lagenodelphis hosei), and a number of seabirds of the family Laridae.
Reproduction
The size at sexual maturitySexual 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 only confidently known for the female of the species, being around 600 mm in fork length, although the male has been estimated to reach maturity at between 600 and 650 mm.
In the Atlantic, the species is known to spawn from spring through to early autumn,
although fish living in waters greater than 27 degrees Celsius spawn year round. However, even when year-round spawning occurs, there are seasonal peaks, with fish in the Western Pacific Ocean showing these peaks in May and in December – January.
The fish is oviparous, producing pelagic eggs and larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e. The larval stages have been studied in detail by Richards (2006), with the diagnostic features of the larvae include a supraoccupital crest and distinctive patterns of pigment
Pigment
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...
and melanophores. The growth of the fish has also been studied, with the size of fish at 1, 2, 3, 4 and 5 years ages are estimated to be 30, 46, 59, 69 and 77 cm in length respectively. The migration pattern of juveniles is poorly known, with only a migration from equatorial spawning grounds to the coasts of Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
recorded, often floating in the currents under large mats of Sargassum
Sargassum
Sargassum is a genus of brown macroalga in the order Fucales. Numerous species are distributed throughout the temperate and tropical oceans of the world, where they generally inhabit shallow water and coral reefs. However, the genus may be best known for its planktonic species...
.
Importance to humans
Herring
Herring is an oily fish of the genus Clupea, found in the shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea. Three species of Clupea are recognized. The main taxa, the Atlantic herring and the Pacific herring may each be divided into subspecies...
, but are taken in large quantities as bycatch. Their flesh is said to be of fair to excellent standard, depending on personal preferences, but generally fetch a low price at markets because they are relatively unknown. Archaeological evidence from the Kapingamarangi and Nukuoro Atolls in the Caroline Islands
Caroline Islands
The Caroline Islands are a widely scattered archipelago of tiny islands in the western Pacific Ocean, to the north of New Guinea. Politically they are divided between the Federated States of Micronesia in the eastern part of the group, and Palau at the extreme western end...
of Micronesia
Micronesia
Micronesia is a subregion of Oceania, comprising thousands of small islands in the western Pacific Ocean. It is distinct from Melanesia to the south, and Polynesia to the east. The Philippines lie to the west, and Indonesia to the southwest....
suggests the prehistoric people of these islands caught large amounts of rainbow runner as food, thought to have been captured by 'trolling' lure hooks from canoes.
Commercial fishery
The rainbow runner is rarely targeted as a commercial fishFishery
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,...
, however, large amounts of the species often turn up as bycatch from tuna and shark fisheries, with the bycatch from the West Indian Tuna Fishery alone totaling 720–1877 t between 1985–94. In recent years this figure has increased, with global catches as estimated by the FAO peaking at 18,940 t per year in 1998 before declining to around 15,000 t per year in 2000/01. This bycatch is nearly always kept and sold at market, either fresh, salted or frozen.
The methods used to take most rainbow runner are purse seines, as well as hook and line techniques and other native fishing methods. At least one case 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 has been reported from this species on the Virgin Islands
Virgin Islands
The Virgin Islands are the western island group of the Leeward Islands, which are the northern part of the Lesser Antilles, which form the border between the Caribbean Sea and the Atlantic Ocean...
.
Recreational fishery
There is a minor recreational fisheryAngling
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...
for rainbow runner in parts of the world. Often they are taken while trolling for other species such as tuna and mackerel, but are often targeted inshore by anglers on the west coast of the Americas using surface 'popper' style lures. The fish are caught on a wide variety of lures and baits, with deep diving lures, surface lures and even saltwater flies used to good measure. The species takes a wide variety of baits including live and cut fish, squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
, octopus
Octopus
The octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms...
, and probably other crustaceans resembling their natural food. They are renowned as gamefish, especially at larger sizes. The species themselves are also commonly used as bait, either as live bait or dead bait rigged to be troll
Troll
A troll is a supernatural being in Norse mythology and Scandinavian folklore. In origin, the term troll was a generally negative synonym for a jötunn , a being in Norse mythology...
ed behind game boats for larger species such as billfish
Billfish
The term billfish is applied to a number of different large, predatory fish characterised by their large size and their long, sword-like bill. Billfish include the sailfish and marlin, which make up the family Istiophoridae, and the swordfish, sole member of the family Xiphiidae...
and tuna
Tuna
Tuna is a salt water fish from the family Scombridae, mostly in the genus Thunnus. Tuna are fast swimmers, and some species are capable of speeds of . Unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red coloration derives from myoglobin, an...
.