Size at maturity and egg capsules of the softnose skates Bathyraja brachyurops (Fowler,1910) and Bathyraja macloviana (Norman,1937) (Elasmobranchii:Rajidae) in the SW Atlantic (37º 00' - 39º 30' S)

Abstract

The softnose skates Bathyraja brachyurops and Bathyraja macloviana represent an important portion of the skate catches of the Uruguay an traw lingfleet in the south western Atlantic. From March to October 2004, specimens of these species were collected at 75-200m depth range in the area situated between latitudes 37 00¢–39 30¢S. For B.brachyurops, total leng that which 50% of the specimens were retained by the gear was 68.0cm for both sexes; TL50 was estimated at 65.4cm for males and 67.0cm for females. For B.macloviana, total length at which 50% of the specimens were retained was 56.0 – 57.0cm for both sexes; TL50 was estimated at 53.5cm for males and 52.0cm for females. Egg capsule length varied from 79–91mm in B.brachyurops and 69–75.5m min B. macloviana.In both species, capsules displayed striated surfaces and similar gross morphology, although egg capsules of B.macloviana had more robust anterior horns and a smaller size than those of B.brachyurops. Egg capsules of the latteral so exhibited microscopical prickles. Capsule edges were laterally keeled with a groove along the keel,and a straight and transverse velum was present in the egg capsules of both species.