Raja straeleni (lat.) Is a species of cartilaginous fish of the rhombic family of rays of the order of stingrays. They live in tropical waters of the central and southeastern Atlantic Ocean between 15 ° C. w. and 30 ° s. w. They are found at a depth of up to 800 m. Their large, flattened pectoral fins form a rhombic disk with a protruding snout. The maximum recorded length is 70 cm. Eggs are laid. They are not the target fishing target [1] [2] [3] .
| Raja straeleni |
|
| Scientific classification |
|---|
| No rank : | Bilateral symmetrical |
|
| International scientific name |
|---|
Raja straeleni Poll , 1951 |
|
Content
The species was first scientifically described in 1951 [4] . The holotype is a male 62 cm long, caught at a depth of 100-110 m ( ) [5] [3] .
These demersal ocean-dodging ramps live in the eastern Atlantic off the coast of Angola , Benin , Cameroon , Equatorial Guinea , Gabon , Gambia , Ghana , Guinea-Bissau , Liberia , Mauritania , Namibia , Nigeria , Togo and South Africa . They are found on the continental shelf and in shallow bays at a depth of 80 to 800 m, mostly 100-300 m. They make regular migrations, keep closer to the shore in summer, and go to a depth in winter [2] [3] .
The broad and flat pectoral fins of these slopes form a rhombus disk with a slightly protruding snout tip and rounded edges. On the ventral side of the disc are 5 gill slits, nostrils and mouth. On the long tail there are lateral folds [1] . The snout is blunt. The dorsal surface of the disc is covered with black spots and spikes. The main background is gray or taupe. Sometimes there are ocular marks. The ventral surface is white. Young stingrays have a uniform color. The tail is quite thick. [6] . The maximum recorded length is 70 cm and the mass is 1.4 kg [2] .
Like other rhombic, these stingrays lay eggs enclosed in a rigid horn capsule with protrusions at the ends. Embryos feed exclusively on yolk . The diet of adults consists of crustaceans and bony fish [2] .
These skates are not subject to targeted fishing. Caught in by-catch. “The wings are eaten. The data for the assessment of the conservation status by the International Union for Conservation of Nature are insufficient [3] .
- ↑ 1 2 Froese, Rainer, and Daniel Pauly, eds. Family Rajidae - Skates (Neopr.) . FishBase
- ↑ 1 2 3 4 Raja straeleni (English) in the FishBase database.
- ↑ 1 2 3 4 Raja straeleni (English) . The IUCN Red List of Threatened Species .
- ↑ Poll M. Expédition océanographique Belge dans les eaux côtières africaines de l'atlantique sud (1948-1949). Poissons. I. Généralités, II. Sélaciens et Chimères // Résultats scientifiques de l'expédition océanographique belge dans les eaux côtières de l'Atlantique Sud (1948-1949). - 1951. - Vol. 4, No. (1) . - P. 1–154.
- ↑ Raja straeleni (neopr.) . Shark-References. Date of treatment December 2, 2016.
- ↑ Compagno, LJV & Ebert, DA & Smale, MJ Guide to the sharks and rays of Southern Africa. - London: New Holland Ltd, 1989.
- Species Raja straeleni (English) in the World Register of Marine Species .