The
Atlantic blue marlin (
Makaira nigricans) is a species of
marlinMarlin, family Istiophoridae, are fish with an elongated body, a spear-like snout or bill, and a long rigid dorsal fin, which extends forward to form a crest. Its common name is thought to derive from its resemblance to a sailor's marlinspike...
endemic to the
Atlantic OceanThe 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...
. The Atlantic blue marlin (hereafter, marlin) feeds on a wide variety of
organismIn biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
s near the surface. By using its bill, it can stun, injure, or kill while knifing through a school of prey and then return later at its leisure to eat. Marlin is a popular
game fishGame 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...
and has commercial value because its meat has a relatively high fat content.
Marlin are distributed throughout the Atlantic's tropical and temperate waters; they are more populous in the western parts. It is a
blue waterMaritime geography is often discussed in terms of four loosely-defined regions: Riverine, brown water, green water, and blue water.-Brown water:...
fish that spends the majority of its life in the open sea, far away from land. Females can grow up to four times the weight of males, reaching 540–1800 kg (1,190.5–3,968.3 lb). Marlin have few predators apart from man; the World Conservation Union does not currently consider it a threatened species.
Some other historic English names for the Atlantic blue marlin are the
Cuban black marlin,
ocean gar, and
ocean guard.
Taxonomy and naming
The Atlantic blue marlin is one of three species in the genus
MakairaMakaira is a genus of marlins and spearfishes. It includes the black, Atlantic blue, and Indo-Pacific blue marlins.- Sustainable consumption :...
. This name is derived from the Greek word
machaira, meaning "a short sword or bent dagger", and the Latin
machaera, "sword".
The specific epithet
nigricans is Latin for "becoming black".
The Atlantic blue marlin is part of the
billfishThe 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...
family Istiophoridae and is in the
perchPerch is a common name for fish of the genus Perca, freshwater gamefish belonging to the family Percidae. The perch, of which there are three species in different geographical areas, lend their name to a large order of vertebrates: the Perciformes, from the Greek perke meaning spotted, and the...
-like order
PerciformesThe 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...
. In addition, it is in the suborder Xiphioidei and is a member of the subclass
NeopterygiiNeopterygii is a group of Actinopteri animals. Neopterygii means "new fins". There are only few changes during their evolution from the earlier actinopterygians. They appeared somewhere in the Late Permian, before the time of the dinosaurs. The Neopterygii is a very successful group of fishes,...
, which means "new wings". It is also in the class of
ActinopterygiiThe Actinopterygii or ray-finned fishes constitute a class or sub-class of the bony fishes.The ray-finned fishes are so called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines , as opposed to the fleshy, lobed fins that characterize...
, which includes ray-finned fishes and spiny rayed fishes, and the superclass
OsteichthyesOsteichthyes , also called bony fish, are a taxonomic group of fish that have bony, as opposed to cartilaginous, skeletons. The vast majority of fish are osteichthyes, which is an extremely diverse and abundant group consisting of over 29,000 species...
, which includes all of the bony fishes.
The Atlantic blue marlin was first described in 1802 by Bernard Germain de Lacépède. Some other names that have been used in the past are
Histiophorus herschelii (Gray, 1838),
Tetrapturus herschelii (Gray, 1838),
Makaira ampla ampla (Poey, 1860),
Tetrapturus amplus (Poey, 1860),
Orthocraeros bermudae (Mowbray, 1931), and
Makaira perezi (Buen, 1950).
The status of the Indo-Pacific blue marlin (
Makaira mazara) as a separate species is under debate. Genetic data suggests that, although the two groups are isolated from each other, they are both the same species. A separate study by V. P. Buonaccorsi, J. R. Mcdowell, and Graves indicated that both Indo-Pacific and Atlantic show "striking phylogeographic partitioning" of mitochondrial and microsatellite
lociIn the fields of genetics and genetic computation, a locus is the specific location of a gene or DNA sequence on a chromosome. A variant of the DNA sequence at a given locus is called an allele. The ordered list of loci known for a particular genome is called a genetic map...
. This study presented both populations as members of one species, with the only genetic exchange occurring when Indo-Pacific blue marlin migrate to and contribute genes to the Atlantic population.
Physical description
The biggest females are more than four times as heavy as the biggest males. Males rarely exceed 160 kilograms (352.7 lb) in weight, and females commonly weigh over 540 kilograms (1,190.5 lb). The longest females can reach a length of more than 4 metres (13.1 ft) with the bill, from eye to tip, constituting about 20% of the total body length. Both sexes have twenty-four vertebrae, of which eleven are precaudal and thirteen are caudal.
This marlin has two
dorsal finA 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 and two anal fins. The fins are supported by bony spines known as
raysThe Actinopterygii or ray-finned fishes constitute a class or sub-class of the bony fishes.The ray-finned fishes are so called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines , as opposed to the fleshy, lobed fins that characterize...
. Its first dorsal fin has 39 to 43 rays from front to back. Its second dorsal fin has 6 to 7 rays. Its first anal fin, which is similar in shape and size to the second dorsal fin, has 13 to 16 rays, and the second anal fin has 6 to 7 rays. The pectoral fins, which have 19 to 22 rays, are long and narrow and can be drawn in to the sides of the body. The pelvic fins are shorter than the pectorals, have a poorly developed membrane, and are depressible into ventral grooves. Its first anal fin, along with its pectoral and caudal fins, can be folded into grooves. This streamlines the fish and thereby reduces
dragIn fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...
.
The body is blue-black on top with a silvery white underside. It has about fifteen rows of pale, cobalt-colored stripes, each of which has round dots and/or thin bars, located on both sides of the fish. The first dorsal fin membrane is dark blue or almost black and has no dots or marks. Other fins are normally brownish-black, sometimes with a hint of dark blue. The bases of the first and second anal fins have a hint of silvery white.
Marlin can rapidly change color and usually appear bright blue when hunting. The coloration results from pigment-containing iridophores and light-reflecting cells.
The body is covered with thick, bony, elongated scales that have one, two, or three posterior points, with one being the most common form.
The bill is long and stout. Both the jaws and the palatines (the roof of the mouth) are covered with small, file-like teeth. The
lateral line systemThe 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 a group of
neuromastsThe 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...
rooted in lateral line canals that can sense weak water motions and large changes in pressure. It has the appearance of a net. It is obvious in immature specimens but unclear in adults, becoming progressively embedded in the skin. The anus is just in front of the origin of the first anal fin.
Range and migration
The Atlantic blue marlin is the most tropical of the
billfishThe 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...
es. Its latitudinal range changes seasonally and extends from about latitude 45°N to about
latitude 35°SThe 35th parallel south is a circle of latitude that is 35 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, the Indian Ocean, Australasia, the Pacific Ocean and South America....
. It is less abundant in the eastern Atlantic where it mostly occurs off Africa between the latitudes of
25°NThe 25th parallel north is a circle of latitude that is 25 degrees north of the Earth's equatorial plane. It crosses Africa, Asia, the Indian Ocean, the Pacific Ocean, North America and the Atlantic Ocean....
and
25°SThe 25th parallel south is a circle of latitude that is 25 degrees south of the Earth's equatorial plane, just south of the Tropic of Capricorn...
. The marlin usually inhabits waters warmer than 24 °C (75.2 °F) but has been found at surface water temperatures as high as 30.5 °C (86.9 °F) and as low as 21.7 °C (71.1 °F). Water color is also important, as marlin prefer
blue waterMaritime geography is often discussed in terms of four loosely-defined regions: Riverine, brown water, green water, and blue water.-Brown water:...
.
Its range expands northward during the warmer months and contracts towards the equator during colder months.
Marlin can undertake long migrations, including repeatedly between the
CaribbeanThe Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
Islands and
VenezuelaVenezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
and the Bahamas, as well as between the Caribbean
Saint Thomas, U.S. Virgin IslandsSaint Thomas is an island in the Caribbean Sea and with the islands of Saint John, Saint Croix, and Water Island a county and constituent district of the United States Virgin Islands , an unincorporated territory of the United States. Located on the island is the territorial capital and port of...
and West
AfricaAfrica 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...
. It is unknown if the trans-Atlantic fish ever return to the western Atlantic, despite an extensive tagging project in the eastern Atlantic. Several fish were later recaptured in the same general area where they were tagged, implying reverse migration after/over several years, but there is insufficient data to accurately determine seasonality.
Predators and parasites
The
great white sharkThe great white shark, scientific name Carcharodon carcharias, also known as the great white, white pointer, white shark, or white death, is a large lamniform shark found in coastal surface waters in all major oceans. It is known for its size, with the largest individuals known to have approached...
and shortfin mako are predators of the Atlantic blue marlin.
Blue marlins have many parasites. They include parasites from the following groups;
digeneaDigenea is a subclass within the Platyhelminthes consisting of parasitic flatworms with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults are particularly common in the digestive tract, but occur throughout the organ systems of all classes of vertebrates...
(flukes), didymozoidea (tissue flukes),
monogeneaMonogenea are a group of largely ectoparasitic members of the flatworm phylum Platyhelminthes, class Monogenea.-Characteristics:Monogenea are very small parasitic flatworms mainly found on skin or gills of fish....
(gillworms),
cestodaThis article describes the flatworm. For the medical condition, see Tapeworm infection.Cestoda is the name given to a class of parasitic flatworms, commonly called tapeworms, of the phylum Platyhelminthes. Its members live in the digestive tract of vertebrates as adults, and often in the bodies...
(tapeworms), nematoda (roundworms),
acanthocephalaAcanthocephala is a phylum of parasitic worms known as acanthocephales, thorny-headed worms, or spiny-headed worms, characterized by the presence of an evertable proboscis, armed with spines, which it uses to pierce and hold the gut wall of its host...
(spiny-headed worms), copepods,
barnacleA barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...
s
cookiecutter sharkThe cookiecutter shark , also called the cigar shark, is a species of small dogfish shark in the family Dalatiidae. This shark occurs in warm, oceanic waters worldwide, particularly near islands, and has been recorded from as deep as . It migrates vertically up to every day, approaching the...
s.
RemoraThe remora , sometimes called a suckerfish or sharksucker, is an elongated, brown fish in the order Perciformes and family Echeneidae...
s are commonly found attached to Blue marlins, often inside the opercula.
Life cycle
Growth and maturity
Atlantic blue marlin reaches
sexual maturitySexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
at the age of two to four years. Males reach sexual maturity at a weight of 35–44 kg (77.2–97 lb) and females at 47–61 kg (103.6–134.5 lb).
Marlin breed in late summer and fall. Females may spawn as many as four times in one season. They often release over seven million
eggsAn egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
at once, each approximately 1 millimetre (0.0393700787401575 in) in
diameterIn geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
. Few reach sexual maturity. The planktonic young drift freely in the ocean's
pelagic zoneAny water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...
. Larvae inhabit the west central Atlantic off
GeorgiaGeorgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
,
North CarolinaNorth Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
,
FloridaFlorida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
,
JamaicaJamaica is an island nation of the Greater Antilles, in length, up to in width and 10,990 square kilometres in area. It is situated in the Caribbean Sea, about south of Cuba, and west of Hispaniola, the island harbouring the nation-states Haiti and the Dominican Republic...
, Bahamas, and
AreciboArecibo may refer to:*Arecibo, Puerto Rico, a municipality located by the Atlantic Ocean*Arecibo Observatory, a very sensitive radio telescope located approximately south-southwest from the city of Arecibo...
and also the southwest Atlantic off
BrazilBrazil , 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...
.
The larvae may grow as much as 16 millimetre (0.62992125984252 in) in a day. On their sides and
dorsal surfaceIn anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
they are blue-black in color, while ventrally they are white. Both the caudal fin and the caudal peduncle (the narrow part of the fish's body to which the caudal or tail fin is attached) are clear. There are two iridescent blue patches on the head, and some individuals have darker spots on their back. In adolescents, the first dorsal fin is large and concave, gradually reducing in proportion to body size with continued growth. Males may live for 18 years, and females up to 27.
Diet and feeding
The larvae feed upon a variety of
zooplanktonZooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
along with drifting fish eggs and other larvae. They progress to feeding on a wide range of fishes, particularly scombrids such as
mackerelMackerel is a common name applied to a number of different species of fish, mostly, but not exclusively, from the family Scombridae. They may be found in all tropical and temperate seas. Most live offshore in the oceanic environment but a few, like the Spanish mackerel , enter bays and can be...
and
tunaTuna 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...
;
squidSquid 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...
; and also, especially near oceanic islands and
coral reefCoral 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...
s, on juvenile inshore fish. Studies of stomach contents in both the Atlantic and Pacific have found that smaller schooling scombrids such as frigate mackerel,
bullet tunaThe bullet tuna, Auxis rochei rochei, is a subspecies of tuna, in the family Scombridae, found circumglobally in tropical oceans in open surface waters to depths of 50m . Its maximum length is 50.0 cm....
, and
skipjack tunaThe skipjack tuna, Katsuwonus pelamis, is a medium-sized perciform fish in the tuna family, Scombridae. It is otherwise known as the aku, arctic bonito, mushmouth, oceanic bonito, striped tuna, or victor fish...
make up a substantial proportion of their diet. Squid, including the large
Humboldt squidThe Humboldt squid , also known as jumbo squid, jumbo flying squid, pota or diablo rojo , is a large, predatory squid found in the waters of the Humboldt Current in the Eastern Pacific Ocean. They are most commonly found at depths of , from Tierra del Fuego to California...
, and deep-sea fishes such as
pomfretPomfret are perciform fishes belonging to the family Bramidae.They are found in the Atlantic, Indian, and Pacific Oceans, and the largest species, the Atlantic pomfret, Brama brama, grows up to long....
and
snake mackerelGempylidae is a family of perciform fishes, commonly known as snake mackerels or escolars.They are elongate fishes with a similar appearance to barracudas, having a long dorsal fin, usually with one or finlets trailing it. The largest species, including the snoek, Thyrsites atun, grow up to two...
, are also important prey items in certain areas. Blue marlin have been recorded to take prey as large as
white marlinWhite Marlin are large, elongated fish with a large upper jaw that forms a spear which is round in cross-section. They are dark blue to chocolate-brown in color...
, as well as
yellowfinThe yellowfin tuna is a species of tuna found in pelagic waters of tropical and subtropical oceans worldwide.Yellowfin is often marketed as ahi, from its Hawaiian name ahi although the name ahi in Hawaiian also refers to the closely related bigeye tuna. The species name, albacares can lead to...
and
bigeye tunaThe bigeye tuna, Thunnus obesus, is an important food fish and prized recreational game fish. It is a true tuna of the genus Thunnus, belonging to the wider mackerel family Scombridae....
in the 100 pounds (45.4 kg) range. Conversely, they are also capable of feeding on small but numerous prey such as
filefishFilefish are tropical to subtropical tetraodontiform marine fish of the diverse family Monacanthidae. Found in the Atlantic, Pacific and Indian Oceans, the filefish family contains approximately 107 species in 26 genera...
and
snipefishThe snipefishes are two species of fishes found in tropical and subtropical oceans at depth down to . According to FishBase, they are part of the family Centriscidae, but some authorities split that family, in which case the genus Macroramphosus is in the family Macroramphosidae...
.
Scientists and fishermen have long debated the extent to which blue marlin and other billfish use their elongated upper jaw in feeding. A 2007 Japanese study of stomach contents of fish captured in a commercial trolling fishery found that 130 undigested prey items obtained from 227 blue marlin had spearing, slashing and other injuries that were judged to have been inflicted by the bill.
Economic importance
Marlin are often caught as
bycatchThe term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...
in tuna longline fisheries. Marlin has commercial value throughout the world, with landings totalling 3,064 metric tons in 2000. Their meat has a high fat content. It is particularly valued in Japan for
sashimiSashimi is a Japanese delicacy. It consists of very fresh raw meat, most commonly fish, sliced into thin pieces.-Origin:The word sashimi means "pierced body", i.e...
. In Hawaii, Blue marlin meat is commonly smoked and sold by roadside vendors.
Because of their relative rarity, beauty, and sporting qualities, marlin are considered one of the most prestigious catches a recreational fisherman can make. The IGFA (International Game Fish Association) all-tackle world record is 1,402 pounds 2 ounces (636 kg). The sportfishing pursuit of marlin and other billfish is a multi-million dollar industry that includes hundreds of companies and thousands of jobs for boat operators, boat builders,
marinaA marina is a dock or basin with moorings and supplies for yachts and small boats.A marina differs from a port in that a marina does not handle large passenger ships or cargo from freighters....
s, dealerships, and
fishing tackleFishing tackle, is a general term that refers to the equipment used by fishermen when fishing. Almost any equipment or gear used for fishing can be called fishing tackle. Some examples are hooks, lines, sinkers, floats, rods, reels, baits, lures, spears, nets, gaffs, traps, waders and tackle...
manufacturers and dealers. The most established marlin fisheries are found along the eastern seaboard and the Gulf Coast of the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, the Bahamas and several other Caribbean islands (notably St Thomas and
Puerto RicoPuerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
), Venezuela,
BrazilBrazil , 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...
, and Bermuda.
Conservation
The Atlantic blue marlin is under intense pressure from longline fishing. In the Caribbean region alone, Japanese and Cuban fishermen annually take over a thousand tons. All vessels within 200 miles (321.9 km) of the U.S. coastline are required to release any
billfishThe 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...
caught. However, the survival rate of released fish is low because of damage during capture.
In 2010, Greenpeace International added the Atlantic blue marlin to its seafood red list. "The Greenpeace International seafood red list is a list of fish that are commonly sold in supermarkets around the world, and which have a very high risk of being sourced from unsustainable fisheries. The World Conservation Union does not currently consider it a threatened species."
In popular culture
In
Ernest HemingwayErnest Miller Hemingway was an American author and journalist. His economic and understated style had a strong influence on 20th-century fiction, while his life of adventure and his public image influenced later generations. Hemingway produced most of his work between the mid-1920s and the...
's novella
The Old Man and the SeaThe Old Man and the Sea is a novel written by American author Ernest Hemingway in 1951 in Cuba, and published in 1952. It was the last major work of fiction to be produced by Hemingway and published in his lifetime. One of his most famous works, it centers upon Santiago, an aging fisherman who...
a fisherman named Santiago battles an Atlantic blue marlin for three days off the coast of Cuba.
The blue marlin is in the NDS game
Animal Crossing: Wild Worldis a 2005 social simulation video game developed and published by Nintendo for the Nintendo DS handheld game console, and is the second game in the Animal Crossing series....
and Wii game Animal Crossing: City Folk.