Shortbill spearfish
Short-beaked marlin ( Tetrapturus angustirostris )
The short-snouted marlin ( Tetrapturus angustirostris ) is a large predatory fish, which is found in tropical and subtropical Pacific and Indian Ocean. He avoids coasts, its range extends in the Pacific from 40 ° north to 35 ° south latitude, in the Indian Ocean, it lies between 20 ° north and 45 ° south latitude.
Features
The short-snouted Marlin is a maximum of 2.30 meters long, but usually remains just below two meters. The average length between the eye and the tail caught in the central South Pacific specimens at 1.35 meters, with catches from the eastern Pacific, it is 1.50 meters. The published maximum weight is 52 kg and the average weight is 18 kg. The body is elongated, laterally flattened and is densely covered with elongate flakes, terminating at its trailing edge in three to five points. The single side line is clearly visible. The number of vertebrae is 24, 12 trunk and 12 caudal vertebrae. The gonads are Y -shaped.
The fish are dark blue on the back, silvery white on the sides brownish to bluish and on the ventral side. On the sides, there are no spots or other patterns. The first dorsal fin is black and blue with no screening, the other fins brown or brown - black, the bases of the anal fins often silvery white. The first dorsal fin is supported 45 to 50 fin rays, the second 6-7 The first dorsal fin has in front a high peak that is higher than the body height of the fish. Then declines sharply and remains on until the 19th dorsal spine at the same level to drop again.
Of the two anal fins, the first 12 to 15, the second 6-8 fin rays. The second dorsal and anal fins, the second face each other symmetrically and are very similar in shape and size. The pectoral fins are supported 17 to 19 fin rays. The pelvic fins are narrow, twice as long as the pectoral fins and reach 15% of the body length. The tail fin shaft is laterally strongly flattened and provided on each side with a double keel and a flat notch on the dorsal and the ventral side. The anus is located before the beginning of the first anal fin in the distance, which is usually longer than the height of the first anal fin.
Similar to the closely related Mediterranean Marlin his spear- like elongated, round in cross-section rostrum is much shorter than for other spearfishing and reached only 15 % of the body length. The extended lower jaw reaches more than ² / ³ of Oberkieferrostrums. Both jaws and the palatine bone are covered with fine teeth, gill rakers are missing, the right and left Branchiostegalmembranen have grown together but free from isthmus.
Way of life
The short-snouted Marlin is an oceanic, pelagic fish, which does not normally approaches the coasts. From long hikes enterprising Indo-Pacific species, there are only occasional sightings and catches of the South Atlantic. It is assumed that the spawning grounds are located in the Indo-Pacific. In longline fisheries in the equatorial Indian Ocean the fewest specimens were caught in the upper water layers (0 to 200 meters), the most in depths of 915-1830 meters.
Like all Marlins is Tetrapturus angustirostris a predator that feeds on fish, cephalopods and crustaceans. Among the prey fish are snake mackerel, mackerel, flying fish, sea bream, jellyfish and lance fish, bonito. Deep-sea fish such as lantern fish and deep- Beilfische missing. He also eats not so large prey fish such as other Marlins.
The fish spawn in the western Indian Ocean during the winter months, in the central Pacific in March. Also, the pelagic eggs and fish larvae occur mainly in winter. The eggs have a diameter of one to 1.6 mm, they are colorless, semi-transparent and contain a yellowish- brown fat drops.
Use
The Kurzschnäuzigen Marlin is not specifically adjusted. He is rarely caught as bycatch in fisheries targeting subjects or tunas with longlines or fished from deep sea anglers. Its flesh has not the high quality of other Marlins, but fresh or frozen marketed mainly in Japan, as sashimi or used for the production of fish sauce.