144 
NOAA 
National Marine 
Fisheries Service 
Fishery Bulletin 
f*> established 1881 
Spencer F. Baird 
First U S. Commissioner 
of Fisheries and founder 
of Fishery Bulletin 
Exploitation and reproduction of the bullnose 
ray {Myliobatis freminvillei ) caught in an 
artisanal fishery in La Pared, Margarita 
Island, Venezuela 
Email address for contact author: tagliaficoa@gmail.com 
Abstract— Species of the genus Myli- 
obatis have been poorly assessed 
because of a lack of available in- 
formation regarding their capture 
and life history. We provide valuable 
data based on the commercial land- 
ings of the bullnose ray (Myliobatis 
freminvillei), which we studied dur- 
ing 2 separate time periods (October 
2005-December 2007 and January- 
December 2013). A total of 187 in- 
dividuals 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 over- 
all sex ratio (females to males: 4:5); 
however, differences were found be- 
tween the annual sex ratio in 2005, 
2006, and 2013. Estimated capture 
per unit of effort for this species was 
0.8 individuals/trip (standard de- 
viation [SD] 1.3) or 2.9 kg/trip (SD 
5.5), showing an increase in effort 
through time and significant differ- 
ences between years. Approximately 
25% of both sexes were shorter than 
the estimated median DW at ma- 
turity. No pattern in the reproduc- 
tive cycle was identified because of 
the lack of landings during several 
months; however, mature individuals 
were observed frequently through- 
out the study period; gravid females 
were observed on only 2 occasions. 
This study provides baseline biologi- 
cal information on the life history of 
the bullnose ray for necessary fish- 
ery management. 
Manuscript submitted 14 January 2015. 
Manuscript accepted 23 December 2015. 
Fish. Bull. 114:144-152 (2016). 
Online publication date: 21 January 2016. 
doi: 10.7755/FB.114.2.2 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
Alejandro Tagliafico (contact author ) 12 
Nicolas Eheirsaniv 
Maria Salome Rangel 1 - 2 
Nestor Rago 3 
1 Escuela de Ciencias Aplicadas del Mar 
Nucleo de Nueva Esparta 
Universidad de Oriente 
Calle La Marina 
Boca de Rio, 6304 Isla de Margarita, Venezuela 
2 National Marine Science Centre 
Southern Cross University 
2 Bay Drive 
Coffs Harbour, New South Wales 2450, Australia 
3 Universidad Nacional de Costa Rica 
Escuela de Biologia 
Avemda 1, Calle 9 
Heredia 86-3000, Costa Rica 
Elasmobranch overfishing has been 
documented since the late 1940s 
(Castro, 2013) and recent analyses 
have demonstrated that population 
diminution has occurred around the 
world, with at least one in 4 species 
being actually threatened with ex- 
tinction (Dulvy et al., 2014). None- 
theless, numerous species of rays and 
skates have been poorly studied, pre- 
venting definition of their status and 
identification of threats (Molina and 
Lopez, 2015). Such is the case for the 
genus Myliobatis, which comprises 11 
species (White, 2014). Of those spe- 
cies, 6 have been documented as data 
deficient by the International Union 
for Conservation of Nature (IUCN) 
in the IUCN Red List of Threatened 
Species, vers. 2015.4, available at 
website, accessed December 2015), 
2 have been classified as species of 
least concern, and the remaining 3 
species have been categorized as en- 
dangered, near threatened, or have 
not been assessed to date. The bull- 
nose ray (Myliobatis freminvillei) is 
included within the data-deficient 
group, as a result of the lack of avail- 
able information required to evalu- 
ate population trends; as a conse- 
quence, the need for further investi- 
gations of its biology and the fishery 
are required to re-assess the status 
of this species in the IUCN Red List 
(Stehmann, 2009). 
The bullnose ray is a benthic-pe- 
lagic eagle ray widely distributed in 
the western Atlantic and captured 
mainly with artisanal long lines, gill- 
nets, and industrial shrimp trawls 
(Cervigon et al., 1992; Stehmann, 
2009; Froese and Pauly, 2015). In 
Brazil, a similar species, the south- 
ern eagle ray (M. goodei), is discarded 
as bycatch of beach seining (Velasco 
et al., 2011). However, in many Ven- 
ezuelan coastal communities, the 
