Spearfishes
Spearfishes | ||||||||||||
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White marlin ( Kajikia albida ) |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Istiophoridae | ||||||||||||
Rafinesque , 1810 |
The spearfishes (Istiophoridae), for species from the genera Istiompax , Kajikia and Makaira , the name marlin is also used , are large predatory fish of the open high seas. They live in warmer areas of the Atlantic , Pacific , Indian and Mediterranean . They are excellent swimmers who can reach high speeds and make long, transoceanic hikes. All species are popular with sport fishermen and many are already threatened. In contrast to its sister species , the swordfish ( Xiphias gladius ), which has a flattened "sword", its rostrum is round in cross-section.
features
Spearfishes have a long, laterally flattened trunk that merges into a slender tail stalk that carries two keels on each side. The caudal fin is forked and, like the pectoral fins, sickle-shaped. The sailfish ( Istiophorus ) have an oversized, irregularly shaped first dorsal fin . The very long first dorsal fin and the first anal fin can be laid back in furrows. The name is given to the upper jaw “spear”, which is round in cross-section (the rostrum that is grown together from premaxillaria and maxillaria). It is much shorter than the swordfish's "sword" . The lateral line organ is well developed in juvenile animals and regresses somewhat with increasing age. The scales are sunk into the skin, small and pointed. Fanfish and spearfish have 24 vertebrae .
The largest species, the blue marlin , is five meters long, while the Tetrapturus georgii, which lives in the Mediterranean and Eastern Atlantic, is 1.85 meters long as the smallest species.
nutrition
Marlin hunt in groups near the surface of sardines , mackerels , Hornhechte , flying fish , gold and Carangidae . They coordinate their chases and encirclement hunts using color signals that are barely visible to the human eye (rapid color change). The large, irregularly shaped, dark dorsal fin, which is laid down in a channel when swimming quickly, also helps to round up and scare the prey that is pushed to the surface. Sea birds such as gannets and frigate birds are also beneficiaries .
Systematics
The cladogram shows the family relationships:
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There are five genera with nine species. The sailfish ( Istiophorus platypterus ) has a sail-shaped first dorsal fin that is higher than the body height and can therefore be easily distinguished from the other species.
- Istiophoridae family (sailfish and spearfish)
- Genus Istiompax Whitley, 1931
- Black marlin ( Istiompax indica (Cuvier, 1832) )
- Genus sailfish ( Istiophorus lacepède, 1801 )
- Sailfish or Sailfish ( Istiophorus platypterus (Shaw, 1792) )
- Genus Kajikia Hirasaka & Nakamura, 1947
- White marlin ( Kajikia albida (Poey, 1860) )
- Striped marlin ( Kajikia audax (Philippi, 1887) )
- Genus Makaira Lacepède, 1802
- Blue marlin ( Makaira nigricans Lacepède, 1802 )
- Genus Tetrapturus Rafinesque, 1810
- Short-snouted marlin ( Tetrapturus angustirostris Tanaka, 1915 )
- Mediterranean marlin ( Tetrapturus belone Rafinesque, 1810 )
- Round-scale marlin ( Tetrapturus georgii Lowe, 1841 )
- Long-nosed marlin (
- Genus Istiompax Whitley, 1931
swell
literature
- Kurt Fiedler: Textbook of Special Zoology, Volume II, Part 2: Fish , Gustav Fischer Verlag, Jena 1991, ISBN 3-334-00339-6 .
- Izumi Nakamura: FAO Species Catalog An Annotated and Illustrated Catalog of Marlins, Sailfishes, Spearfishes and Swordfishes Known to date. Rome 1985, ISBN 92-5-102232-1 online
- Joseph S. Nelson : Fishes of the World. 4th edition. John Wiley & Sons, Hoboken NJ et al. 2006, ISBN 0-471-25031-7 .
Web links
- Spearfishes on Fishbase.org (English)
- ftp://ftp.fao.org/docrep/fao/009/ac480e/AC480E05.pdf (larval development)
Individual evidence
- ↑ Bruce B. Collette, Jan R. McDowell, John E. Grawes: Phylogeny of recent Billfishes (Xiphioidei). Bulletin of Marine Science: 79 (3), 455-468, 2006