Kingdom: Animalia

Phylum: Chordata

Class: Chondrichthyes

Order: Rajiformes

Family: Rajidae

Genus: Raja

Species: R. clavata

Specimen Description

Since, the Raja Clavata is living at the bottom of the continental shelf and upper slope of the coastal sea floor, the jaws and teeth are exclusively designed to feed on larger crustaceans and small teleost fish such as sandeels, small gadoids and dragonets, The jaws are equipped  with teeth are similar in upper and lower jaws, less than 60 rows of unicuspid teeth, usually 36–44 in the upper jaw. Teeth in males are sharper than in females and juveniles of characteristic cockscomb shape, with heavy, bent, oblique cusps, strong distal cusplets and prominent serrations but no blades, cusps of lower teeth not prominently protruding when mouth is closed. An interdorsal ridge present and very prominent.

About the Animal

The Thornback Ray (Raja clavata) is probably one of the commonest skates encountered by divers, being among the most abundant rajids in the north-eastern Atlantic and Mediterranean. As with all skates, the body is flattened and disc-shaped, with the pectoral fins broadly expanded and joined to the head and body. The tail is distinctly demarcated from the disc-like body, relatively narrow, and about as long as body length. The upper surface of the disc and tail are covered with numerous thorns, which become thickened with button-like bases (known as bucklers) once the skate is sexually mature, hence the species’ common name.

Reference:

http://www.arkive.org/thornback-skate/raja-clavata/

http://www.marinespecies.org/aphia.php?p=taxdetails&id=105883

https://www.sharktrust.org/shared/downloads/factsheets/thornback_ray_st_factsheet.pdf