Reproductive biology of the Rasptail skate Rostroraja velezi (Rajiformes: Rajidae)

The Rasptail skate Rostroraja velezi is commercially exploited in artisanal elasmobranch fisheries along the west coast of Baja California Sur, Mexico, but information on its life history is limited. This study aimed to investigate the reproductive biology of R. velezi. A total of 105 specimens were caught from April 2008 to May 2012, including the largest reported specimen with 121 cm total length, 96 cm disc width (D-W). Females attained larger sizes than males. Males and females presented functional gonads. There was an asymmetry in the testes of males, with the left testis being larger. Histological analysis of the reproductive biology of R. velezi was performed here for the first time. The presence of sperm storage in females and spermatogenic development beginning at the first stages of maturity in males was recorded. It was possible to identify the development of secretions in the club, baffle and terminal zone of the oviducal gland. D-W at maturity, defined as the D-W at which 50% of the population is mature, was estimated at 68-72 cm for females and 65.1 cm for males. Egg-bearing females caught in April and May presented one egg capsule per uterus. Furthermore, a description of the egg capsule of R. velezi is provided. Elucidating the reproductive cycle, the type of reproductive strategies, and the fecundity of R. velezi will allow us to understand the impact of fisheries on this species.

Automated summary

The study investigated the reproductive biology of Rostroraja velezi commercially exploited in artisanal fisheries along the west coast of Baja California Sur, Mexico. It found that females were larger than males, males had asymmetrical testes, and recorded the presence of sperm storage in females and early spermatogenic development in males. Results will help understand the impact of fisheries on this species.