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Billfish In The Indian Ocean
Of the twelve species of billfish, there are six species of Billfish in the Indian Ocean. Background The term billfish refers to the large fishes of the family Istiophoridae, comprising marlin and sailfish, and of the family Xiphiidae, comprising swordfish. Billfish are epipelagic and highly migratory fishes found throughout the world's oceans, typically inhabiting the coastal and offshore waters of tropical and temperate oceans. They are normally found in the upper 200 metres of water layers above the thermocline but may occur in depths up to 800 metres. They migrate into temperate or cold waters for feeding and back to tropical waters for spawning. They are “characterized by the prolongation of the upper jaw, much beyond the lower jaw into a long rostrum which is flat and swordlike (swordfish) or rounded and spearlike (sailfishes, spearfishes and marlins).” All billfish species are sexually dimorphic with the females attaining larger sizes than males. Spawning occur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Billfish
The term billfish refers to a group of saltwater predatory fish characterised by prominent pointed bills (rostra), and by their large size; some are longer than . Extant billfish include sailfish and marlin, which make up the family Istiophoridae; and swordfish, sole member of the family Xiphiidae. They are 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. Billfish are pelagic and highly migrato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Makaira
''Makaira'' (Latin via Greek: ''μαχαίρα'' "sword") is a genus of marlin in the family Istiophoridae. It includes the Atlantic blue, and Indo-Pacific blue marlins. In the past, the black marlin was also included in this genus, but today it is placed in its own genus, ''Istiompax''. Species * ''Makaira nigricans'' Lacepède, 1802 (Atlantic blue marlin) * ''Makaira mazara'' (Jordan & Snyder, 1901) (Indo-Pacific blue marlin) Although they are traditionally listed as separate species, recent research indicates that the Atlantic blue marlin (''Makaira nigricans'') and Indo-Pacific blue marlin (''Makaira mazara'') may be parapatric In parapatric speciation, two subpopulations of a species evolve reproductive isolation from one another while continuing to exchange genes. This mode of speciation has three distinguishing characteristics: 1) mating occurs non-randomly, 2) gene ... populations of the same species. References Marine fish genera {{Scombroide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trolling (fishing)
Trolling is a method of fishing where one or more fishing lines, baited with lures or bait fish, are drawn through the water. This may be behind a moving boat, or by slowly winding the line in when fishing from a static position, or even sweeping the line from side-to-side, e.g. when fishing from a jetty. Trolling is used to catch pelagic fish such as salmon, mackerel and kingfish. In American English, trolling can be phonetically confused with trawling, a different method of fishing where a net (trawl) is drawn through the water instead of lines. Trolling is used both for recreational and commercial fishing whereas trawling is used mainly for commercial fishing. Trolling from a moving boat involves moving quite slowly through the water. This can be accomplished with the use of a special trolling motor. Multiple lines are often used, and outriggers can be used to spread the lines more widely and reduce their chances of tangling. Downriggers can also be used to keep the lures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longline Fishing
Longline fishing, or longlining, is a commercial fishing angling technique that uses a long ''main line'' with baited hooks attached at intervals via short branch lines called ''snoods'' or ''gangions''.Method and Apparatus for Long Line and Recreational Bait Fishing Patent application 20080202013. 28 August 2008. A snood is attached to the main line using a clip or swivel, with the hook at the other end. Longlines are classified mainly by where they are placed in the . This can be at the surface or at the bottom. Lines can also be set by means of an anchor, or left to drift. Hundreds or even thousands of baited hooks can hang from a single line. This can l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gillnetting
Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is generally referred to as a "cork line." The line along the bottom of the panels is generally weighted. Traditionally this line has been weighted with lead and may be referred to as "lead line." A gillnet is normally set in a straight line. Gillnets can be characterized by mesh size, as well as colour and type of filament from which they are made. Fish may be caught by gillnets in three ways: # Wedged – held by the mesh around the body. # Gilled – held by mesh slipping behind the opercula. # Tangled – held by teeth, spines, maxillaries, or other protrusions without the body penetrating the mesh. Most often fish are gilled. A fish swims into a net and passes only part way through the mesh. When it struggles to free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juveniles of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non- marine species (freshwater fish not saltwater fish) that are caught (either intentionally or unintentionally) but regarded as generally "undesirable" are referred to as "rough fish" (mainly US) and " coarse fish" (mainly UK). In 1997, the Organisation for Economic Co-operation and Development (OECD) defined bycatch as "total fishing mortality, excluding that accounted directly by the retained catch of target species". Bycatch contributes to fishery decline and is a mechanism of overfishing for unintentional catch. The average annual bycatch rate of pinnipeds and cetaceans in the US from 199 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swordfish
Swordfish (''Xiphias gladius''), also known as broadbills 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 , and exceptionally up to depths of 2,234 m. They commonly reach in length, and the maximum reported is in length and in weight.Gardieff, S. Swordfish.' Florida Museum of Natural History. Accessed 26 December 2011 They are the sole member of their family, Xiphiidae. Taxonomy and etymology The swordfish is named after its long pointed, flat bill, which resembles a sword. The species name, ''Xiphias gladius'', derives from Greek (''xiphias'', "swordfish"), itself from (''xiphos'', "sword") and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indo-Pacific Sailfish
The Indo-Pacific sailfish (''Istiophorus platypterus'') 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''. It is theorized by marine biologists that the 'sail' (dorsal fin array) of the sailfish may serve the purpose of a cooling and he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailfish
The sailfish is one or 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. Species Two sailfish species have been recognized.McGrouther, M. (2013). Sailfish, Istiophorus platypterus.' Australian Museum. Retrieved 26 April 2013. 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 aro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shortbill Spearfish
The shortbill spearfish (''Tetrapturus angustirostris''), sometimes called the short-nosed spearfish, is a species of marlin native to the Indian and Pacific Oceans, with occasional records from the Atlantic Ocean. This species occurs in open waters not far from the surface. This species can reach a length of , though most do not exceed . The maximum recorded weight for this species is . It is of minor importance to commercial fisheries Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often ... and is also a game fish. Short bill spearfish are characterized by a slim frame with a blue body that is silver underneath. Shortbill also possess a very short bill extending from their upper jaw. References * Tony Ayling & Geoffrey Cox, ''Collins Guide to the Sea Fishes of New Zealand'', (Wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Striped Marlin
The striped marlin (''Kajikia audax'') is a species of marlin found in tropical to temperate Indo-Pacific oceans not far from the surface. It is a desirable commercial and game fish. The striped marlin is a predator that hunts during the day in the top 100 m or so of the water column, often near the surface. One of their chief prey is sardines. Description The Striped Marlin consists of 42-48 rays on its tall first dorsal fin that is almost the same or longer than its body depth while the second dorsal fin is much smaller. They have torpedo-like and compressed bodies. They have around 10-20 clear, visible bluish stripes on the sides of their bodies even after death. The color of their bodies is dark blue or black above and silvery-white on the bottom. Striped Marlin has an average length of and a maximum length of and can weight up to . Life Cycle Striped Marlin reached sexual maturity at a age of 1-2 years or for males and 1.5-2.5 years or for females. They can live up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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