Bathyraja spinossisima (Beebe & Tee-Van, 1941)

David A. Ebert & Chante D. Davis, 2007, Descriptions of skate egg cases (Chondrichthyes: Rajiformes: Rajoidei) from the eastern North Pacific., Zootaxa 1393, pp. 1-18 : 14-15

[[ Bathyraja spinossisima (Beebe & Tee-Van, 1941) ?? ]]

Unidentified deepsea skate egg case “A”

Description: The egg cases of this unidentified species (Figure 12a) are very large, 188 to 198 mm in length, with MAW about 58-62% of ECL. The surface is finely striated, smooth to the touch, and without a fibrous outer layer. Surface under magnification appear as shallow, wavy, concave striations. The LKW is very broad, about 14% of MAW, and folds over itself. Attachment fibers are absent. Anterior apron border broad and concave, anterior horns more robust than posterior, inner and out keels present, horn length 53-57% ECL, curving dorsally relative to aspect of egg case, and flattening to tips and curling. Posterior apron border almost straight, transverse, thinning along edge, and slightly less than width of anterior apron. Posterior horns 58- 67% of ECL, curving medially and ventrally, slightly longer than anterior, flattening to tips, and with outer and inner keels present along edges. Color in situ a light yellowish, but becoming a bronze to greenish brown after preservation (Figure 12b).

Remarks: Three examples of these large unidentified skate egg cases were collected by the Monterey Bay Aquarium Research Institute (MBARI) remote operated vehicle (ROV) Tiburon off San Diego, California at a depth of 1,820 m (Figure 12b). These three egg cases were nested among some rocks in what appears to be a nursery area as numerous egg cases were observed on this rough rocky relief substrate (Figure 12c). An adult male and adult female B. spinossisima were observed to swim past the ROV and it is possible that these egg cases may be of that species. However, these egg cases are unlike the egg case that we have tentatively identified as B. spinossisima in that these are not plush to the touch. The only known species that we do not have an example of its egg case is A. badia . Given the high degree of endemism found in skates and the remote offshore location of where these egg cases were observed they may represent an otherwise unknown species. Additional examples of these egg cases, perhaps some with developing embryos, will shed light on their proper identification.

Material examined: CAS 224345, three egg cases, collected by MBARI remote operated vehicle Tiburon in situ, off San Diego, California (32.9635 N, - 121.0484 W), 1820 m, 29 April 2004.