What is Raja or skate?
Classification:
Phylum Chordata
Order: Hypotremata
Class: Chondrichthyes
Genus: Raja
Habitat: Raja is a marine cartilage fish which lies at the bottom of temperate and tropical seas. It is more common in northern hemisphere. It is commonly called skate.Skates are cartilaginous fish belonging to the family Rajidae in the superorder Batoidea of rays. More than 150 species have been described, in 17 genera. Softnose skates and pygmy skates were previously treated as subfamilies of Rajidae, but are now considered as distinct families
Habits : (i) It swims by flapping action of pectoral fins.
i(i) It is a carnivorous fish which eats small fishes, crustaceans etc. It catches the prey and tears with its rasping teeth.
(iii) It shows respiration.
(iv) It shows protective colouration for defence.
(v) There is sexual dimorphism. Males have claspers. Fertilization is internal. Female is oviparous.
Development is direct.
External Characters:
(i) Body is dorsoventrally flattened, rhomboidal and differentiated into anterior rhombic disc and a
slender tail.
(ii) Disc is formed of head, trunk and confluent pectoral fins.
(iii) Head is produced in a short snout with a pair of dorsal eyes. Spiracles are found just below the
eyes.
(iv) Ventral mouth is provided with numerous sharp and rasping teeth for tearing the prey.
(v) First dorsal fin and second dorsal fins are near caudal fin.
(vi) There is sexual dimorphism. Male has a pair of claspers near pelvic fin.
Economic importance: Many species of Raja are edible.
