Raja bathyphila

Author: Holt and Byrne, 1908

Raja (Rajella) bathyphila Holt and Byrne, 1908

Status in World Register of Marine Species:
Accepted name: Rajella bathyphila (Holt and Byrne, 1908) (updated 2009-06-25)

Diagnosis: snout short, moderately elongate, the tip somewhat pronounced in large specimens; disc heart-shaped, with outer corners rounded in juveniles, but rhombic and the outer corners angled in halfgrown and adult specimens. Upper surface entirely spinulose, but bare patches in centres of pectoral fins and on sides of body in adult males. A thorn generally present in front of and behind eye, never thorns on snout, 0-2 thorns on each side between spiracles, 2-3 median thorns on nape, one on middle of shoulder, and a triangle of 3 thorns on each side of shoulder; a regular median row of 33-41 thorns (31-32 in juveniles) from shoulder to first dorsal fin (those on body reduced in size in adults), and in larger specimens an additional parallel row of 10-30 hooked thornlets on either side of midline on front part of tail; dorsal fins confluent; underside smooth, except variously developed lateral bands of prickles on tail. Colour: upper surface plain dark greyish-brown in young, changing usually to greyish-white in adults; underside varying with growth, the disc predominantly dark brown in juveniles, but always with large white markings along midbody, especially on midbelt, white with broad dark margins in half-grown specimens, uniformly white in adults; tail in juveniles white in midline at front, entirely white in last third, becoming almost dark in half-grown specimens and may be somewhat greyish (as also claspers) in adults. Size: to about 90 cm TL.

Habitat: benthic on continental slopes at 600 2,050 m, mainly deeper than 1,400 m; rare. Food: no data. Reproduction: oviparous; egg-cases about 90 by 50 mm (excluding horns); embryos about 130 mm TL at hatching.

Distribution: in the area Denmark Strait and Rockall Trough. Elsewhere, in western North Atlantic north of 45° N, but probably more widely distributed in very deep water.