Borneo river shark

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Borneo river shark
Systematics
without rank: Sharks (selachii)
Superordinate : Galeomorphii
Order : Ground Sharks (Carcharhiniformes)
Family : Requiem sharks (Carcharhinidae)
Genre : River sharks ( Glyphis )
Type : Borneo river shark
Scientific name
Glyphis fowlerae
Compagno , WT White & Cavanagh , 2010

The Borneo river shark ( Glyphis fowlerae ) is a type of river shark (genus Glyphis ) within the Requiem shark (Carcharhinidae). The shark is extremely rare and only occurs in the rivers and in light brackish water on the coast of the Malaysian state of Sabah in northeast Kalimantan .

features

Distribution area

The previously known specimens of the Borneo river shark were 50 to 78 cm long. The shark has a stocky body that is brown-gray on the top and white on the underside and has a noticeable dark spot on the sides and at the base of the pectoral fins . The lower and rear edges of the fin and the tip of the caudal fin are dark or black. The front edge of the pectoral fin is slightly convex. The first dorsal fin has a slightly concave rear edge, but is not sickle-shaped. Its rear tip reaches almost over the beginning of the pelvic fin attachment. The second dorsal fin reaches 58 to 68% of the height of the first dorsal fin, the anal fin 74 to 102% of the height of the second dorsal fin. The anal fin has a slight indentation on its rear edge. An interdorsal ridge is missing. The short rostrum is broadly rounded when viewed from above or below, the eyes are small and there are no injection holes . The teeth are usually not visible when the mouth is closed.

The Borneo river shark differs from the closely related Irrawaddy river shark ( Glyphis siamensis ) in the number of vertebrae (196 to 209), the color and the higher second dorsal fin.

Way of life

The way of life of the species is largely unknown. The type locality consists of flat sandbanks with a muddy bottom. The water has a low salinity . Like the other species of the genus, it is probably viviparous and forms a yolk sac placenta ( placental viviparous ).

literature

  • Leonard Compagno , Marc Dando, Sarah Fowler: Sharks of the World. Princeton Field Guides, Princeton University Press , Princeton and Oxford 2005; Pp. 133-134, ISBN 978-0-691-12072-0 .
  • LJV Compagno, WT White, RD Cavanagh 2010: Glyphis fowlerae sp. nov., a new species of river shark (Carcharhiniformes; Carcharhinidae) from northeastern Borneo. In: PP Last, WT White, JJ Pogonoski (Ed.): Descriptions of new sharks and rays from Borneo. CSIRO Marine and Atmospheric Research Paper no. 32; Pp. 29-44. ( Full text ; PDF; 7.6 MB)

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