Marlin is a species of large, long-nosed marine fish characterized by an elongated body, a long dorsal fin, and a rounded snout extending from the muzzle. They are wanderers found around the world near the surface of the sea and are carnivorous, feeding mainly on other fish. They are consumed as food and are highly valued by sport fishermen.
Origin and Description
Marlin is a member of the marlin family, a perch order.
Four main types of marlin are usually mentioned:
- blue marlin, found throughout the world, — very large fish, sometimes reaching a weight of 450 kg or more. It is a dark blue animal with a silvery belly and often lighter vertical stripes. Blue marlin tend to sink deeper and tire faster than other marlins;
- black marlin becomes as huge or even bigger than blue marlin. It has been known to reach a weight of over 700 kg. The Indo-Pacific species is blue or cyan, gray above and lighter below. Its distinctive stiff pectoral fins are angled and cannot be flattened into the body without force;
- striped marlin, another fish in the Indo-Pacific region, bluish above and white below with pale vertical stripes. Usually it does not exceed 125 kg. The striped marlin is renowned for its fighting ability and has a reputation for spending more time in the air than in the water after being hooked. They are known for long runs and tail walks;
- White marlin (M. albida or T. albidus) is limited to the Atlantic and is blue-green in color with a lighter belly and pale vertical stripes on the sides. Its maximum weight is about 45 kg. White marlin, despite the fact that they are the smallest species of marlin, weighing no more than 100 kg, are in demand due to their speed, elegant jumping ability and the difficulty of baiting and catching them.
Appearance and Features
Signs of blue marlin are as follows:
- spiky front dorsal fin that never reaches the maximum depth of the body;
- Pectoral (lateral) fins are not rigid, but can be folded back towards the body;
- Cobalt blue back that fades to white. The animal has pale blue stripes that always disappear upon death;
- the general shape of the body is cylindrical.
Fun Fact: Black marlin are sometimes referred to as “bullfish” due to their extreme strength, large size, and incredible stamina when hooked. All this obviously makes them a very popular fish. They can sometimes have a silver haze covering their body, which means they are sometimes referred to as “silver marlin”.
Signs of black marlin:
- low dorsal fin relative to body depth (smaller than most marlin);
- beak and body shorter than other species;
- dark blue back fades to silver belly;
- stiff pectoral fins that cannot fold.
White marlin is easy to recognize. Here's what to look for:
- dorsal fin rounded, often deeper than body;
- lighter, sometimes green coloration;
- spots on belly, as well as on the dorsal and anal fins.
The characteristic features of the striped marlin are as follows:
- a pointed dorsal fin that may be higher than its body depth;
- visible light blue stripes that remain even after death;
- thinner, more compressed body shape;
- flexible pointed pectoral fins.
Where does marlin live?
Blue marlin — pelagic fish, but they are rarely found in ocean waters less than 100 meters deep. Compared to other marlins, the blue one has the most tropical distribution. They can be found in the eastern and western waters of Australia and depending on warm ocean currents, as far south as Tasmania. Blue marlin can be found in the Pacific and Atlantic Oceans. Some experts believe that blue marlin, found in the Pacific and Atlantic oceans, — these are two distinct species, although this view is disputed. It seems that the point is that marlin in the Pacific Ocean tend to be larger than in the Atlantic.
Black marlin usually lives in the tropical Indian and Pacific oceans. They swim in coastal waters and around reefs and islands, but also roam the open sea. Very rarely they come to temperate waters, sometimes traveling around the Cape of Good Hope into the Atlantic.
White marlin live in the tropical and seasonally temperate waters of the Atlantic, including the Gulf of Mexico, the Caribbean Sea and the Western Mediterranean. They can often be found in relatively shallow water near the shore.
Striped marlin are found in tropical and temperate waters of the Pacific and Indian Oceans. Striped marlin — a highly migratory pelagic species found at depths of 289 meters. They are rarely seen in coastal waters, except when there are sharp drops into deeper waters. Striped marlin are mostly solitary, but form small groups during the spawning season. They hunt prey in surface waters at night.
Now you know where the marlin lives. Let's see what this fish eats.
What does marlin eat?
Blue marlin — a solitary fish known to make regular seasonal migrations, moving towards the equator in winter and summer. They feed on epipelagic fish including mackerel, sardines and anchovies. They may also feed on squid and small crustaceans when given the opportunity. Blue marlins are among the fastest fish in the ocean and use their beaks to cut through tight schools and return to eat their dazed and injured victims.
Black marlin — the pinnacle of predators that feed mainly on small tuna, but also other fish, squid, cuttlefish, octopuses and even large crustaceans. What is defined as “smaller fish” is a relative term, especially considering that a large marlin weighing over 500 kg was found with a tuna weighing over 50 kg in its stomach.
Fun fact: Studies off the east coast of Australia show that black marlin catches increase during the full moon and the week after their prey species move deeper from the surface layers, forcing the marlin to forage on a wider territory.
White marlin feed near the surface during the daytime on a variety of fish, including mackerel, herring, dolphins and flying fish, as well as squid and crabs.
The striped marlin is a very strong predator, feeding on a variety of small fish and aquatic animals such as mackerel, squid, sardines, anchovies, lancet fish, sardines and tuna. They hunt in areas from the surface of the ocean to a depth of 100 meters. Unlike other types of marlin, the striped marlin cuts its prey with its beak, and does not pierce it.
Character and lifestyle features
Marlin — an aggressive, highly predatory fish that responds well to the splash and trail of a well presented artificial lure.
Interesting fact: Fishing for marlin — one of the most exciting challenges for any angler. Marlin is fast, athletic and can be very huge. Striped marlin — the second fastest fish in the world, swimming at speeds up to 80 km/h. The speed of black and blue marlin also leaves most of the other fish that follow them.
Once caught on a hook, marlin show acrobatic abilities worthy of a ballerina — or perhaps it would be more correct to compare them to a bull. They dance and jump through the air at the end of your line, giving the angler the fight of their life. No wonder marlin fishing has an almost legendary status among anglers around the world.
The striped marlin is one of the most dominant fish species, with some interesting behaviors:
- these fish are solitary in nature and usually live alone;
- they form small groups during the spawning season;
- this species hunts during the daytime;
- they use their long beak for hunting and also for defensive purposes;
- these fish are often found swimming around lure balls (small fish swimming in compact spherical formations) causing them to inhale. They then swim through the lure ball at high speed, catching weaker prey.
Social Structure and Reproduction
Blue marlin are often migratory and therefore little is known about their spawning periods and behaviour. However, they are very prolific, producing up to 500,000 eggs per spawn. They can live up to 20 years. Blue marlin spawn in the central Pacific and central Mexico. They prefer water temperatures between 20 and 25 degrees Celsius and spend most of their time near the surface of the water.
Known spawning areas for black marlin, based on the presence of larvae and juveniles, are limited to warmer tropical areas when water temperatures are around 27-28°C. Spawning occurs at specific times in specific regions in the western and northern Pacific Ocean, in the Indian Ocean on the northwest shelf off Exmouth, and most widely in the Coral Sea off the Great Barrier Reef near Cairns during October and November. Here, suspected pre-spawning behavior was observed when the «larger» females were followed by several smaller males. The number of eggs of a female black marlin can exceed 40 million per fish.
Striped marlin reach sexual maturity at the age of 2-3 years. Males mature earlier than females. Spawning takes place in summer. Striped marlin — they are multiply mating animals whose females release eggs every few days, with 4–41 spawning events occurring during the spawning season. Females can produce up to 120 million eggs in a spawning season. The spawning process of white marlin has not yet been studied in detail. It is only known that spawning takes place in summer in deep ocean waters with high surface temperatures.
Natural enemies of marlins
Marlins have no other natural enemies other than humans who fish them commercially. Some of the best marlin fishing in the world takes place in the warm waters of the Pacific Ocean around Hawaii. Probably more blue marlin have been caught here than anywhere else in the world, and some of the largest marlin ever recorded have been caught on this island. The western city of Kona is world famous for its marlin fishing not only because of the frequency of catching big fish, but also because of the skill and experience of its top captains.
From the end of March to July, charter boats sailing from Cozumel and Cancun encounter masses of blue and white marlin, as well as other white fish such as sailboats, heading into the warm waters of the Gulf Stream to the area. Blue marlin tend to be smaller here than in the central Pacific. However, the smaller the fish, the sportier it is, so the fisherman will still find himself in an exciting fight.
The first black marlin ever caught on line and reel was caught by a Sydney doctor who was fishing from Port -Stevens, New South Wales, in 1913. The east coast of Australia is now a mecca for marlin fishing, with blue and black marlin frequently caught on fishing charters in the area.
The Great Barrier Reef is the only confirmed breeding site for black marlin, making eastern Australia one of the most popular black marlin fishing destinations in the world.
Striped marlin are traditionally the main whalefish species in New Zealand, although anglers occasionally catch blue marlin there. In fact, blue marlin catches in the Pacific have increased over the past ten years. Now they are constantly found in the bays of the islands. Waihau Bay and Cape Runaway are particularly well-known marlin fishing grounds.
Population and species status
According to a 2016 assessment, Pacific blue marlin is not overfished. Population estimates for the Pacific blue marlin are being conducted by the Billfish Working Group, a division of the International Scientific Committee on Tuna and Tuna-like Species in the North Pacific.
The valuable white marlin is one of the most exploited fish in the open ocean. It is the subject of intense international recovery efforts. A new study now shows that a similar species, the roundfish, makes up a relatively high proportion of fish identified as “white marlin”. Thus, the current biological information on white marlin is likely to be superseded by the second species, and past population estimates of white marlin are currently uncertain.
Black marlin have not yet been assessed as to whether they are threatened or endangered. Their meat is sold chilled or frozen in the United States and prepared as sashimi in Japan. However, they are banned in some parts of Australia due to their high selenium and mercury content.
The striped marlin is listed in the Red Book and is a protected species of marlin. In Australia, striped marlin are caught throughout the east and west coasts and are a target species for anglers. The striped marlin is a species that prefers tropical, temperate and sometimes cold waters. Striped marlin are also occasionally caught recreationally off Queensland, New South Wales and Victoria. These recreational catches are managed by state governments.
The striped marlin is not on the IUCN Red List of Threatened Species. However, Greenpeace International included these fish on their seafood red list in 2010, as the numbers of these marlins are declining due to overfishing. Commercial fishing for this fish has become illegal in many regions. People who catch this fish for recreational purposes are advised to throw it back into the water and not consume or sell it.
The catch of striped marlin is managed by quota. This means that the catch of this fish by commercial fishermen is limited by weight. It also limits the type of tackle that can be used to catch striped marlin. Commercial fishermen are required to complete their catch records during each fishing trip and when they land their catch in port. This helps keep track of how many fish are caught.
Because striped marlin is fished by many other countries in the Western and Central Pacific and Indian Oceans, the Western and Central Pacific Fisheries Commission and the Indian Ocean Tuna Commission are the international bodies responsible for managing tropical tuna and other fish in the Pacific. in the Indian Ocean and in the world. Australia is a member of both commissions, along with several other major fishing nations and small island nations.
The commissions meet every year to review the latest available scientific information and set global catch limits for major tuna and flounder species such as striped marlin. They also specify what each Member must do to manage its catch of tropical tuna and flounder species, such as transporting observers, exchanging fishery information and tracking fishing vessels by satellite.
The Commission also sets requirements for the availability of scientific observers, the provision of fishery data, satellite tracking of the fishing vessel and fishing gear to minimize the impact on wildlife.
Marlin — amazing fish species. Unfortunately, they may soon become a threatened species if humans continue to harvest them for industrial purposes. For this reason, various organizations around the world are taking initiatives to stop eating this fish. Marlin can be found in all warm and temperate oceans of the world. Marlin — it is a migratory pelagic species known to travel hundreds of kilometers in ocean currents in search of food. Striped marlin seem to tolerate colder temperatures better than any other species.