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

Abstract

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 JanuaryDecember 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.

Morphological abnormalities in seven American round ray specimens: A review of America's batomorph anomalies

“…In addition, these two countries, together with the USA, possesses the most extensive coverage area of the exclusive economic zone of the American continent (Ehemann et al., 2018; Tovar‐Verba et al., 2020); therefore, their artisanal and industrial fleet is one of the largest compared with the remaining 52 countries of the continent. Since the records belong to coastal species with commercial interest and locally appreciated (Ehemann et al., 2017; González‐González et al., 2020; González‐González & Ehemann, 2019; Santander‐Neto & Faria, 2020; Tagliafico et al., 2016), it seems possible to associate the apparent “increase” in the number of abnormal batomorphs with the high pressure of the artisanal fleet on the elasmobranch resource. In addition, both countries stood out for their economic investment in academic formation and research financing (CNPQr, 2020; CONACYT, 2020; Ehemann, 2020; SEP, 2020), which might complement the results obtained in this study.…”

Manta and devil ray species occurrence and distribution in Venezuela, assessed through fishery landings and citizen science data

“…(2018) study, which proposed the creation of the first southern Caribbean Island marine ecological corridor, stretching from La Orchila Island in Venezuela to Curaçao and Bonaire (Dutch Antilles). In addition, based on recent chondrichthyan fisheries studies from eastern Venezuela (e.g., Cordovés et al, 2009;Giménez-Hurtado et al, 2010;Marquez et al, 2019;Tagliafico et al, 2012Tagliafico et al, , 2016Tagliafico et al, , 2017Tagliafico et al, , 2019Tagliafico et al, , 2021, there is enough scientific information to consider adding the islands of La Tortuga, Margarita and Cubagua to this marine ecological corridor polygon.…”

Myliobatis goodei: Carlson, J., Charvet, P., Avalos, C., Blanco-Parra, MP, Briones Bell-lloch, A., Cardenosa, D., Chiaramonte, G.E., Cuevas, J.M., Derrick, D., Espinoza, E., Mejía-Falla, P.A., Morales-Saldaña, J.M., Motta, F., Naranjo-Elizondo, B., Pacoureau, N., Paesch, L., Pérez Jiménez, J.C., Rincon, G., Schneider, E.V.C., Simpson, N.J., Talwar, B.S. & Pollom, R.

“…Other members of this genus are utilized bycatch and catches are consumed or sold locally (Tagliafico et al 2016). This species is likely to be used similarly where it is caught.…”

“…The Southern Eagle Ray is captured using artisanal longlines, gillnets, beach seines, and industrial shrimp trawls (Velasco et al 2011, Tagliafico et al 2016. There are no known threats in the Northwest and Western Central Atlantic but in the Southwest Atlantic artisanal fisheries are intense.…”