Title

Exploitation and reproduction of the bullnose ray (Myliobatis freminvillei) caught in an artisanal fishery in La Pared, Margarita Island, Venezuela

Document Type

Article

Publication details

Tagliafico, A, Ehemann, N, Rangel, MS & Rago, N 2016, 'Exploitation and reproduction of the bullnose ray (Myliobatis freminvillei) caught in an artisanal fishery in La Pared, Margarita Island, Venezuela', Fishery Bulletin, vol. 114, pp. 144-152.

Article available on Open Access

Peer Reviewed

Peer-Reviewed

Abstract

Species of the genus Myliobatis have been poorly assessed because of a lack of available information regarding their capture and life history. We provide valuable data based on the commercial landings of the bullnose ray (Myliobatis freminvillei), which we studied during 2 separate time periods (October 2005–December 2007 and January– December 2013). A total of 187 individuals were analyzed: 85 females (24.0–96.0 cm in disc width [DW]) and 102 males (22.8–118.0 cm DW). There was no difference in the overall sex ratio (females to males: 4:5); however, differences were found between the annual sex ratio in 2005, 2006, and 2013. Estimated capture per unit of effort for this species was 0.8 individuals/trip (standard deviation [SD] 1.3) or 2.9 kg/trip (SD 5.5), showing an increase in effort through time and significant differences between years. Approximately 25% of both sexes were shorter than the estimated median DW at maturity. No pattern in the reproductive cycle was identified because of the lack of landings during several months; however, mature individuals were observed frequently throughout the study period; gravid females were observed on only 2 occasions. This study provides baseline biological information on the life history of the bullnose ray for necessary fishery management.