Der Spatennasenhai (Scoliodon laticaudus) ist eine Art in der Gattung Scoliodon innerhalb der Requiemhaie (Carcharhinidae). Die Art ist in weiten Teilen des Indischen Ozeans von Tansania bis Indien und im Roten Meer verbreitet.
Der Spatennasenhai ist ein schlanker Hai mit einer Körperlänge von maximal 75 cm und Durchschnittsgrößen zwischen 50 und 60 cm. Er hat eine bronze bis graue Rückenfärbung und einen hellen Bauch ohne Musterung. Er gleicht im Habitus den Blauhaien der Gattung Carcharhinus, besitzt allerdings eine auffällig verlängerte und spatenförmige Schnauzenregion. Er besitzt eine Afterflosse und zwei Rückenflossen, wobei die zweite Rückenflosse deutlich kleiner als die erste und die Analflossen ist. Er besitzt kein Spritzloch und die Augen sind verhältnismäßig klein mit Nickhäuten. Die erste Rückenflosse ist triangulär geformt und deutlich hinter den Brustflossen ansetzend. Das Hinterende der ersten Rückenflosse liegt über den Bauchflossen. Die Analflosse ist wesentlich größer als die zweite Rückenflosse.
Der Spatennasenhai ist eine Flachwasserart und ernährt sich räuberisch von verschiedenen Fischen, vor allem Bodenarten. Die Haie sind lebendgebärend und bilden eine Dottersack-Plazenta aus (plazental vivipar). Die Weibchen bekommen in einem Wurf zwischen einem und 14 Jungtiere mit einer Länge von etwa 13 bis 15 cm. Teilweise können die Spatennasenhaie sehr häufig auftreten und Schulen bilden.
Die Art ist in weiten Teilen des Indischen Ozeans von Tansania bis Indien und Sri Lanka verbreitet. Dabei handelt es sich um einen Flachwasserbewohner des Kontinentalschelfs, der steinige Gründe bevorzugt. Bei den Spatennasenhaien im Westpazifik von Japan bis nach Indonesien und den Philippinen handelt es sich um Scoliodon macrorhynchos, bei denen im Golf von Bengalen um eine dritte, bisher unbeschriebene Art oder um Scoliodon muelleri, der mit Scoliodon laticaudus synonymisiert wurde.[1]
Der Spatennasenhai (Scoliodon laticaudus) ist eine Art in der Gattung Scoliodon innerhalb der Requiemhaie (Carcharhinidae). Die Art ist in weiten Teilen des Indischen Ozeans von Tansania bis Indien und im Roten Meer verbreitet.
The spadenose shark (Scoliodon laticaudus) is a species of requiem shark in the family Carcharhinidae. It is common in the tropical Indian and western Pacific Oceans, where it forms large schools in shallow water. A small shark reaching a length of 74 cm (29 in), the spadenose shark is named for its distinctively flattened, triangular snout. It is a predator of small bony fishes and invertebrates. This species exhibits the most advanced mode of viviparity of any fish, in which the developed embryos form a highly complex placental connection to the mother at a very small size. Females breed year-round, giving birth to six to 18 pups after a gestation period of 5–6 months. The spadenose shark is harmless to humans and is valued by artisanal and commercial fishers for its meat and fins. Its abundance ensures it forms a significant component of many fisheries in South and Southeast Asia. The International Union for Conservation of Nature has assessed this species as Near threatened. This fish is also known as mori in Goa[2]
The first scientific description of the spadenose shark was published in 1838 by the German biologists Johannes Peter Müller and Friedrich Gustav Jakob Henle, in their Systematische Beschreibung der Plagiostomen. The holotype is presumed to be a 42 cm (17 in)-long stuffed specimen in the Zoologisches Museum of Berlin.[3] The generic name Scoliodon is derived from the Greek skolex ("worm") and odon ("tooth"), while the specific epithet laticaudus comes from the Latin latus ("broad" or "wide") and cauda ("tail"). Other common names used for this species include Indian dogfish, sharp-nosed shark, trowel-nose shark, and yellow dog shark.[4]
Phylogenetic analyses based on morphological and molecular data indicate the spadenose shark is one of the most basal members of its family, along with the related genus Rhizoprionodon and Galeocerdo, the tiger shark.[5] In addition, anatomical similarities suggest this species to be the closest living relative of the hammerhead sharks, which diverged from the other carcharhinids some time before the Middle Eocene (48.6–37.2 million years ago).[6]
A small, stocky species, the spadenose shark has a broad head with a distinctive, highly flattened, trowel-shaped snout. The eyes and nares are small. The corners of the mouth are well behind the eyes and have poorly developed furrows at the corners. About 25–33 tooth rows are in the upper jaw and 24–34 tooth rows are in the lower jaw; each tooth has a single slender, blade-like, oblique cusp without serrations. The first dorsal fin is positioned closer to the pelvic than the pectoral fins, which are very short and broad. The second dorsal fin is much smaller than the anal fin. No ridge occurs between the dorsal fins. The back is bronze-gray in color, and the belly is white. The fins are plain, but may be darker than the body. The maximum known length is 74 cm (29 in), though unsubstantiated reports indicate individuals reaching 1.2 m (3.9 ft).[3]
The spadenose shark is found in the western Indo-Pacific from Tanzania to South and Southeast Asia, as far east as Java and Borneo and as far north as Taiwan and Japan. It is typically found close to the coast in water 10–13 m (33–43 ft) deep, often close to rocky bottoms. This shark is frequently reported from the lower reaches of rivers in Malaysia, Sumatra, and Borneo, though whether this species is capable of tolerating fresh water like the bull shark (Carcharhinus leucas) is unclear due to a lack of salinity data from these areas.[3][4]
Abundant in many areas, spadenose sharks often form large schools. It feeds mainly on small bony fishes, including anchovies, codlets, burrowing gobies, and Bombay ducks. Shrimp, crabs, cuttlefish, and stomatopods are also sometimes taken.[3][7] Known parasites of this shark include the tapeworm Ruhnkecestus latipi,[8] and the larvae of ascaridid roundworms.[9]
The spadenose shark has the most advanced form of placental viviparity known in fish, as measured by the complexity of the placental connection and the difference in weight between the egg and the newborn young.[10] Newly ovulated eggs measure only 1 mm (0.039 in) in diameter, while the developing embryos become dependent on their mother for sustenance at a length of only 3 mm (0.12 in). The placental stalk, formed from the yolk sac, has an unusual columnar structure and is covered by numerous long appendiculae that support a massive capillary network, providing a large surface area for gas exchange. The placental tissue contacts the uterine wall in a unique structure called the "trophonematal cup", where nutrients are transferred from the mother's bloodstream into the placenta.[10]
Female spadenose sharks probably mate at least once per year, and breeding takes place year-round. The gestation period of the spadenose shark is 5–6 months long, and the young are born at a length of 12–15 cm (4.7–5.9 in). The litter size is six to 18. Males mature sexually at a length of 24–36 cm (9.4–14.2 in), and females at a length of 33–35 cm (13–14 in). Estimates of the age at maturity range from 6 months to 2 years. The lifespan may be 5 years for males and 6 years for females.[7]
The spadenose shark is harmless to humans. This common species is taken by artisanal and commercial fisheries across its range, using floating and fixed gillnets, longlines, bottom nets, fish traps, trawls, and hook-and-line. The meat is eaten or used as bait for other fishes, the fins are valued for shark fin soup, and the carcasses are processed into fishmeal.[3][11] The meat can also be processed with glacial acetic acid to obtain a gel powder that can be used as a protein supplement in cereal foods, a biodegradable film for wrapping seafood, or a binder in sausages and other foods.[12]
Despite its commercial importance, overall fishery statistics for the spadenose shark are lacking.[1] A 1996 report found it to be the most common coastal shark on Chinese markets.[13] Substantial numbers are caught by Indian and Pakistani fisheries; from 1979 to 1981, an average of 823 tons was caught annually off Verval, India.[7] The spadenose shark is also caught as bycatch, particularly in gillnet fisheries off Kalimantan.[4] The International Union for Conservation of Nature has assessed this species as near threatened; the spadenose shark's relatively short reproductive cycle may render it more resilient to fishing pressure than other sharks, though its low fecundity still merits caution.[1] This shark may also be negatively affected by coastal development, due to its inshore habitat preferences.[7]
The spadenose shark (Scoliodon laticaudus) is a species of requiem shark in the family Carcharhinidae. It is common in the tropical Indian and western Pacific Oceans, where it forms large schools in shallow water. A small shark reaching a length of 74 cm (29 in), the spadenose shark is named for its distinctively flattened, triangular snout. It is a predator of small bony fishes and invertebrates. This species exhibits the most advanced mode of viviparity of any fish, in which the developed embryos form a highly complex placental connection to the mother at a very small size. Females breed year-round, giving birth to six to 18 pups after a gestation period of 5–6 months. The spadenose shark is harmless to humans and is valued by artisanal and commercial fishers for its meat and fins. Its abundance ensures it forms a significant component of many fisheries in South and Southeast Asia. The International Union for Conservation of Nature has assessed this species as Near threatened. This fish is also known as mori in Goa
El tiburón de cabeza plana (Scoliodon laticaudus) es una especie de tiburón de la familia Carcharhinidae.
Los machos pueden alcanzar los 100 cm de longitud total.[2]
Se encuentra desde Somalia, Tanzania, Mozambique y Pakistán hasta Java (Indonesia), Japón, China, Taiwán y Australia.[2]
El tiburón de cabeza plana (Scoliodon laticaudus) es una especie de tiburón de la familia Carcharhinidae.
Scoliodon laticaudus Scoliodon generoko animalia da. Arrainen barruko Carcharhinidae familian sailkatzen da.
Scoliodon laticaudus Scoliodon generoko animalia da. Arrainen barruko Carcharhinidae familian sailkatzen da.
Scoliodon laticaudus (nom vernaculaire : Requin épée) est une espèce de requins qui vit dans les eaux peu profondes (10 à 15 m) de l'océan Indien et d'Océanie.
Scoliodon laticaudus mesure jusqu'à 100 cm.
Caractéristiques : museau aigu, déprimé. Seconde dorsale réduite.
Taille : jusqu’à 80 cm.
Profondeur : benthique et côtier, il évolue en bancs de la surface jusqu’à 50 m.
Alimentation : petits poissons osseux, seiches, crevettes.
Reproduction : vivipare.
Jeunes : 5 à 14 juvéniles mesurant 15 cm à la naissance.
Espérance de vie : 6 ans.
Maturité sexuelle : atteinte à 30 cm pour les deux sexes.
Danger : aucun.
Exploitation humaine : captures fréquentes à la ligne ou au filet.
Géographie : Eaux littorales de l’Indo-Pacifique, de la Tanzanie au Kenya, de l’Indonésie au Japon.
Scoliodon laticaudus (nom vernaculaire : Requin épée) est une espèce de requins qui vit dans les eaux peu profondes (10 à 15 m) de l'océan Indien et d'Océanie.
Yu Padi atau nama saintifiknya Scoliodon laticaudus merupakan ikan air masin. Ia merupakan sejenis ikan dalam keluarga Carcharhinidae dan genus Scoliodon. Ia memiliki ekor berbentuk HETEROCERCAL. [2]
Ia merupakan ikan yang penting secara komersial dan dijual di pasar-pasar sebagai makanan. Penangkapannya memerlukan lesen bagi memastikan ia tidak terancam oleh tangkapan melampau oleh nelayan komersial.[3].
Yu Padi atau nama saintifiknya Scoliodon laticaudus merupakan ikan air masin. Ia merupakan sejenis ikan dalam keluarga Carcharhinidae dan genus Scoliodon. Ia memiliki ekor berbentuk HETEROCERCAL.
Ia merupakan ikan yang penting secara komersial dan dijual di pasar-pasar sebagai makanan. Penangkapannya memerlukan lesen bagi memastikan ia tidak terancam oleh tangkapan melampau oleh nelayan komersial..
