Bathyraja abyssicola Gilbert 1896

Bathyraja abyssicola (Gilbert, 1896)

Description: The egg cases of Bathyraja abyssicola (Figure 2) are large, 108 to 111 mm in length, with MAW about 67–69% of ECL. Egg case surface texture coarse and very rough to the touch, striated, the surface is irregular and with rasp­like denticles. LKW is very narrow, <5% of MAW and with a distinct groove between the lateral keel and case proper. This groove is not present in any other ENP skate egg case. Lateral keels extend onto horns and are also present on inner horns. Anterior apron border of egg case broad and concave, anterior horns more robust than posteriors at base, becoming flattened and thread­like at tips. Posterior apron is nearly straight, broad, and transverse, about 10 mm wider than anterior apron. Posterior horns long, about two times length of anteriors and about 1.2 times ECL, curved inwards, each tapering to a thread­like tip. Attachment fibers present, originating on lateral keel near the junction of exterior base of posterior horns and case. Egg cases removed from a single specimen was a light golden brown in color.

Remarks: Bathyraja abyssicola is a large, deepwater species usually found on the continental slope between 362 and 2906 m, although most records of its capture have come from> 1,000 m deep (Zorzi & Anderson, 1988). It is considered to be a rare species, but recent deepwater surveys along the ENP continental slope have revealed this skate to be more common than previously thought (unpublished data). To the best of our knowledge this is the first confirmed record and description of the egg case of this species.

Material examined: CAS 224336, 141.0 cm TL, west of Alexander Island, Washington (47.4935 N, ­ 125.5185 W), 1428 m, 24 August 2004.