Sailfish | |
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Atlantic sailfish | |
Indo-Pacific sailfish | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Carangiformes |
Family: | Istiophoridae |
Genus: | Istiophorus Lacépède, 1801 |
Type species | |
Scomber gladius (G. Shaw, 1792) | |
Species | |
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Synonyms | |
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The sailfish is one of two species of marine fish in the genus Istiophorus, which belong to the family Istiophoridae (marlins). They are predominantly blue to gray in colour and have a characteristically large dorsal fin known as the sail, which often stretches the entire length of the back. Another notable characteristic is the elongated rostrum (bill) consistent with that of other marlins and the swordfish, which together constitute what are known as billfish in sport fishing circles. Sailfish live in colder pelagic waters of all Earth's oceans, and hold the record for the highest speed of any marine animal.
There is a dispute based on the taxonomy of the sailfish, and either one or two species have been recognized. [3] [4] No differences have been found in mtDNA, morphometrics or meristics between the two supposed species and most authorities now only recognize a single species, Istiophorus platypterus, found in warmer oceans around the world. [4] [5] [6] [7] FishBase continues to recognize two species: [3]
Considered by many scientists the fastest fish in the ocean, [8] sailfish grow quickly, reaching 1.2–1.5 m (4–5 ft) in length in a single year, and feed on the surface or at middle depths on smaller pelagic forage fish and squid. Sailfish were previously estimated to reach maximum swimming speeds of 35 m/s (125 km/h), but research published in 2015 and 2016 indicate sailfish do not exceed speeds between 10–15 m/s (35–55 km/h). During predator–prey interactions, sailfish reached burst speeds of 7 m/s (25 km/h) and did not surpass 10 m/s (35 km/h). [9] [10] Generally, sailfish do not grow to more than 3 m (10 ft) in length and rarely weigh over 90 kilograms (200 pounds).
Some sources indicate that sailfish are capable of changing colours as a method of confusing prey, displaying emotion, and/or communicating with other sailfish. [11] [12] [13] [14]
Sailfish have been documented attacking humans in self-defense; a 100-pound (45-kilogram) sailfish stabbed a woman in the groin when her party tried to catch it. [15]
Sailfish have been reported to use their bills for hitting schooling fish by tapping (short-range movement) or slashing (horizontal large-range movement) at them. [16]
The sail is normally kept folded down when swimming and only raised when the sailfish attack their prey. The raised sail has been shown to reduce sideways oscillations of the head, which is likely to make the bill less detectable by prey fish. [9] This strategy allows sailfish to put their bills close to fish schools or even into them without being noticed by the prey before hitting them. [16] [17]
Sailfish usually attack one at a time, and the small teeth on their bills inflict injuries on their prey fish in terms of scale and tissue removal. Typically, about two prey fish are injured during a sailfish attack, but only 24% of attacks result in capture. As a result, injured fish increase in number over time in a fish school under attack. Given that injured fish are easier to catch, sailfish benefit from the attacks of their conspecifics but only up to a particular group size. [18] A mathematical model showed that sailfish in groups of up to 70 individuals should gain benefits in this way. The underlying mechanism was termed proto-cooperation because it does not require any spatial coordination of attacks and could be a precursor to more complex forms of group hunting. [18]
The bill movement of sailfish during attacks on fish is usually either to the left or to the right side. Identification of individual sailfish based on the shape of their dorsal fins identified individual preferences for hitting to the right or left side. The strength of this side preference was positively correlated with capture success. [19] These side-preferences are believed to be a form of behavioural specialization that improves performance. However, a possibility exists that sailfish with strong side preferences could become predictable to their prey because fish could learn after repeated interactions in which direction the predator will hit. Given that individuals with right- and left-sided preferences are about equally frequent in sailfish populations, living in groups possibly offers a way out of this predictability. The larger the sailfish group, the greater the possibility that individuals with right- and left-sided preferences are about equally frequent. Therefore, prey fish should find it hard to predict in which direction the next attack will take place. Taken together, these results suggest a potential novel benefit of group hunting which allows individual predators to specialize in their hunting strategy without becoming predictable to their prey. [19]
The injuries that sailfish inflict on their prey appear to reduce their swimming speeds, with injured fish being more frequently found in the back (compared with the front) of the school than uninjured ones. When a sardine school is approached by a sailfish, the sardines usually turn away and flee in the opposite direction. As a result, the sailfish usually attacks sardine schools from behind, putting at risk those fish that are the rear of the school because of their reduced swimming speeds. [20]
The sailfish is an epipelagic and oceanic species and shows a strong tendency to approach continental coasts, islands and reefs tropical and temperate waters of the Pacific and Indian oceans.[ citation needed ]
Sailfish in some areas are reliant on coral reefs as areas for feeding and breeding. As witnessed in the Persian Gulf, the disappearance of coral reefs in a sailfish's habitat may be followed by the disappearance of the species from that area. [21]
When freshly hatched, sailfish are hunted by other fishes that mainly survive on eating plankton. The size of their predators increases as they grow, and adult sailfish are not eaten by anything other than larger predatory fish like open ocean shark species and orcas.[ citation needed ]
A tuna is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae (mackerel) family. The Thunnini comprise 17 species across five genera, the sizes of which vary greatly, ranging from the bullet tuna up to the Atlantic bluefin tuna, which averages 2 m (6.6 ft) and is believed to live up to 50 years.
The mackerel, tuna, and bonito family, Scombridae, includes many of the most important and familiar food fishes. The family consists of 51 species in 15 genera and two subfamilies. All species are in the subfamily Scombrinae, except the butterfly kingfish, which is the sole member of subfamily Gasterochismatinae.
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation and parasitoidism. It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators.
Marlins are fish from the family Istiophoridae, which includes 11 species.
The swordfish, also known as the broadbill in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are a popular sport fish of the billfish category, though elusive. Swordfish are elongated, round-bodied, and lose all teeth and scales by adulthood. These fish are found widely in tropical and temperate parts of the Atlantic, Pacific, and Indian Oceans, and can typically be found from near the surface to a depth of 550 m (1,800 ft), and exceptionally up to depths of 2,234 m. They commonly reach 3 m (10 ft) in length, and the maximum reported is 4.55 m in length and 650 kg (1,430 lb) in weight.
The grey reef shark or gray reef shark is a species of requiem shark, in the family Carcharhinidae. One of the most common reef sharks in the Indo-Pacific, it is found as far east as Easter Island and as far west as South Africa. This species is most often seen in shallow water near the drop-offs of coral reefs. It has the typical "reef shark" shape, with a broad, round snout and large eyes. It can be distinguished from similar species by the plain or white-tipped first dorsal fin, the dark tips on the other fins, the broad, black rear margin on the tail fin, and the lack of a ridge between the dorsal fins. Most individuals are less than 1.88 m (6.2 ft) long.
The Atlantic sailfish is a species of marine fish in the family Istiophoridae of the order Istiophoriformes. It is found in the Atlantic Ocean and the Caribbean Sea, except for large areas of the central North Atlantic and the central South Atlantic, from the surface to depths of 200 m (656 ft). The Atlantic sailfish is related to the marlin.
The Greenland shark, also known as the gurry shark or grey shark, is a large shark of the family Somniosidae, closely related to the Pacific and southern sleeper sharks. Inhabiting the North Atlantic and Arctic Oceans, they are notable for their exceptional longevity, although they are poorly studied due to the depth and remoteness of their natural habitat.
The billfish are a group of saltwater predatory fish characterised by prominent pointed bills (rostra), and by their large size; some are longer than 4 m (13 ft). Extant billfish include sailfish and marlin, which make up the family Istiophoridae; and swordfish, sole member of the family Xiphiidae. They are often apex predators which feed on a wide variety of smaller fish, crustaceans and cephalopods. These two families are sometimes classified as belonging to the order Istiophoriformes, a group which originated around 71 million years ago in the Late Cretaceous, with the two families diverging around 15 million years ago in the Late Miocene. However, they are also classified as being closely related to the mackerels and tuna within the suborder Scombroidei of the order Perciformes. However, the 5th edition of the Fishes of the World does recognise the Istiophoriformes as a valid order, albeit including the Sphyraenidae, the barracudas.
Pelagic fish live in the pelagic zone of ocean or lake waters—being neither close to the bottom nor near the shore—in contrast with demersal fish that live on or near the bottom, and reef fish that are associated with coral reefs.
The Indo-Pacific sailfish is a sailfish native to the Indian and Pacific Oceans and is naturalized in the Atlantic where it has entered the Mediterranean Sea via the Suez Canal as a Lessepsian migrant. It is dark blue on top, brown-blue laterally, silvery white underbelly; upper jaw elongated in the form of a spear; first dorsal fin greatly enlarged in the form of a sail, with many black cones, its front squared off, highest at its midpoint; pelvic fins very narrow, reaching almost to the anus; body covered with embedded scales, blunt at end; lateral line curved above pectoral fin, then straight to base of tail. They have a large and sharp bill, which they use for hunting. They feed on tuna and mackerel, some of the fastest fish in the ocean. Most authorities only recognise a single species of sailfish, I. platypterus.
The black marlin is a species of marlin found in tropical and subtropical areas of the Indian and Pacific Oceans approximately between 40 degrees North and 45 degrees South, while in some instances venturing into more temperate waters. Reaching lengths of over 4.5 m (15 ft), It is one of the largest marlins and also one of the largest bony fish. Marlin are among the fastest fish, but speeds may be exaggerated in popular media, such as reports of 132 km/h (82 mph). A 2016 study estimated maximum swimming speeds from muscle contraction times, which in turn limit the tail-beat frequency; the study suggested a theoretical upper limit for the black marlin's burst speed of 36 kilometres per hour (22 mph). Black marlin are fished commercially and are also a highly prized game fish. Black marlins were known to drag ancient Maldivian fishing boats for very long distances until the marlins tired; it would take many hours for the fishermen to row or sail back home. Due to the common misidentification of large billfish such as the black marlin, as well as its highly migratory habits and the lack of research into the species, much about populations are unknown. The species was first known as Tetrapturus indicus and later was reclassified as Makaira indica before taking on its current scientific name. One of the earliest scientific records of black marlin is its description by French zoologist Georges Cuvier in 1832.
The roundscale spearfish is an Istiophoridae species of marlin living in the epipelagic zone of the Atlantic Ocean. It has long been misidentified as white marlin but can be differentiated thanks to their scale shapes that gives its name. Not much is known about this species. It could reach a length of 160 cm and 21,5 kg and has no conservation status yet due to a lack of data.
Forage fish, also called prey fish or bait fish, are small pelagic fish that feed on planktons and other small aquatic organisms. They are in turn preyed upon by various predators including larger fish, seabirds and marine mammals, this making them keystone species in their aquatic ecosystems.
In biology, any group of fish that stay together for social reasons are shoaling, and if the group is swimming in the same direction in a coordinated manner, they are schooling. In common usage, the terms are sometimes used rather loosely. About one quarter of fish species shoal all their lives, and about one half shoal for part of their lives.
Predatory fish are hypercarnivorous fish that actively prey upon other fish or aquatic animals, with examples including shark, billfish, barracuda, pike/muskellunge, tuna, dolphinfish, walleye, perch and salmon. Some omnivorous fish, such as the red-bellied piranha, can occasionally also be predatory, although they are not strictly regarded as obligately predatory fish.
A bait ball, or baitball, occurs when small fish swarm in a tightly packed spherical formation about a common centre. It is a last-ditch defensive measure adopted by small schooling fish when they are threatened by predators. Small schooling fish are eaten by many types of predators, and for this reason they are called bait fish or forage fish.
This is a list of the fastest animals in the world, by types of animal.
Pursuit predation is a form of predation in which predators actively give chase to their prey, either solitarily or as a group. It is an alternate predation strategy to ambush predation — pursuit predators rely on superior speed, endurance and/or teamwork to seize the prey, while ambush predators use concealment, luring, exploiting of surroundings and the element of surprise to capture the prey. While the two patterns of predation are not mutually exclusive, morphological differences in an organism's body plan can create an evolutionary bias favoring either type of predation.
Of the twelve species of billfish, there are six species of Billfish in the Indian Ocean.
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