Raja
Temporal range: Maastrichtian to Present
Raja brachyura
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Superorder: Batoidea
Order: Rajiformes
Family: Rajidae
Genus: Raja
Linnaeus, 1758
Species

See text

Raja, also known as raia, is a genus of skates in the family Rajidae containing 16 species.[1] Formerly a wastebasket genus, many species historically categorized here have been moved to other genera in the family, such as Amblyraja, Beringraja, Dipturus, Leucoraja and Rostroraja.[1] Raja are flat-bodied, cartilaginous fish with a rhombic shapes due to their large pectoral fins extending from or near from the snouts to the bases of their tails. Their sharp snouts are produced by a cranial projection of rostral cartilage. The mouth and gills are located on the underside of the body. They may be either solid-coloured or patterned, and most skates have spiny or thorn-like structures on the upper surface, while some species contain weak electrical organs within their tails. Mating typically occurs in the spring and the female lays numerous eggs per clutch which are encapsulated in leathery cases, commonly known as "mermaid’s purses". Species vary in size, ranging from about 40 to 140 cm (1.3–4.6 ft) in length.[2] These bottom-dwellers are active during both day and night, and typically feed on molluscs, crustaceans and fish. Raja skates are found in the East Atlantic, also in the Mediterranean, and western Indian Ocean, ranging from relatively shallow water to a depth of 800 m (2,600 ft).[2] Skates and related species have fossil records dating from the Upper Cretaceous period, thus this well-adapted species is quite ancient.

Species

There are currently 16 species in this genus:[1]

See also

References

Wikispecies has information related to Raja.
  1. 1 2 3 Last, P.R.; Weigman, S.; Yang, L. (2016). "Changes to the nomenclature of the skates (Chondrichthyes: Rajiformes)". In Last, P.R.; Yearsley, G.R. (eds.). Rays of the World: Supplementary Information. CSIRO Special Publication. pp. 11–34. ISBN 9781486308019.
  2. 1 2 Froese, Rainer and Pauly, Daniel, eds. (2016). Species of Raja in FishBase. January 2016 version.


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