Description of egg capsules of Rasptail Skate Rostroraja velezi (Chondrichthyes: Rajiformes: Rajidae) from northern Peru

Nine egg capsules of the Rasptail Skate (Rostroraja velezi) were collected from their southernmost distributional range in northern Peruvian waters for their description. Egg capsules had a glossy black or dark brown color, with a subrectangular shape, slightly wider at posterior end than at anterior end. Egg capsules when observed under a stereoscope revealed a finely striated surface. Egg capsules ranged from 6.8 to 7.7 cm in length, 4.9 to 6.2 cm in maximum width, and 4.2 to 5.9 cm in minimum width. Anterior horn length was shorter than posterior horn length (0.29% vs. 0.58%). Differences in egg capsule surface and size were observed when compared to capsules of R. velezi from Baja California, Mexico, possibly due to differences in environmental conditions since individuals sampled belong to different marine provinces. Our results represent the second study to describe egg capsules for this species and the first in the Tropical Eastern Pacific marine province.