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Exploitation and reproduction of 
the spotted eagle ray ( Aetobatus narinari ) 
in the Los Frailes Archipelago, Venezuela 
Alejandro Tagliafico (contact author ) 1 
Nestor Rago 1 
Salome Rangel 2 
Jeremy Mendoza 3 
Email address for contact author: tagliaficoa@gmail.com 
1 Instituto Nacionai de Investigaciones Agricolas 
La Asuncion, Isla de Margarita, Venezuela 
Present address Escuela de Ciencias Aphcadas del Mar 
Umversidad de Oriente 
Boca de Rio, Isla de Margarita, Venezuela 
2 Departamento de Ciencias 
Umversidad de Oriente 
Isla de Margarita, Venezuela 
3 Instituto Oceanografico de Venezuela 
Umversidad de Oriente, Apdo. 245 
Cumana, Venezuela 
Abstract — We studied a small artis- 
anal fishery for the spotted eagle ray 
( Aetobatus narinari ) off Margarita 
Island in northeastern Venezuela. 
We analyzed data from 413 fishing 
trips directed at A. narinari over a 
29-month sampling period (August 
2005-December 2007). These trips 
yielded 55,9 metric tons and 1352 
individuals from which a subsample 
of 846 females and 321 males was 
used for biological data. Maximum 
fishing effort and landings occurred 
between February and May, and catch 
per unit of effort was highest between 
December and February and between 
July and October with an overall 
average of 3 individuals and 133 kg 
per trip. The overall sex ratio was 
significantly different from 1:1 with 
a predominance of females. Females 
ranged in size with disc widths (DW) 
from 64 to 226 cm. Males ranged in 
size between 97 and 190 cm DW. 
There was no statistically significant 
difference between male and female 
length-weight relationships. Mean 
fecundity was estimated at 3.09 
embryos per female, and the largest 
embryo measured 44.5 cm DW. 
Females in different maturity stages 
were found in all months, except 
November 2007, the month when all 
females were immature. Postgravid 
females occurred mainly during 
the periods of January-May and 
July-October. Mean length (L 50 ) at 
maturity was estimated at 129.2 cm 
DW for males and 134.9 cm DW for 
females. This study provides much 
needed information on the biology 
and life history of A. narinari for 
the management of an intensive, 
directed, small-scale fishery for this 
little known species in northeastern 
Venezuela. 
Manuscript submitted 20 October 2011. 
Manuscript accepted 7 May 2012. 
Fish. Bull. 110:307-316 (2012). 
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. 
The spotted eagle ray ( Aetobatus 
narinari) until recently had been 
considered a cosmopolitan species 
distributed in tropical and warm, 
temperate waters. However, recent 
genetic analysis indicates that what 
was thought to be a single species is 
actually a species complex with at least 
2 separate species, 1 for the western 
and central Pacific and at least 1 for 
the eastern Pacific and central Atlantic 
(Richards et ah, 2009; Schluessel et 
a3., 2010a). Furthermore, White et 
al. (2010) in a taxonomic review of 
this species complex established 
that Aetobatus ocellatus is the valid 
species name for the Indo-West Pacific 
region. Both species are very similar 
morphologically, and the major physical 
difference occurs in the background 
dorsal coloration (White et al. 2010). 
Because most previous studies have 
been conducted in the Indo-Pacific 
region, this taxonomic redefinition 
significantly reduces the available 
scientific literature on the biology and 
fisheries of A. narinari. In the western 
Atlantic, A. narinari is found from 
Chesapeake Bay and Bermuda to the 
Gulf of Mexico, Caribbean Sea, and 
south to Brazil (Cervigon and Alcala, 
1999). 
Aetobatus narinari is observed us- 
ually in coastal environments, such 
as bays and coral reefs, and occa- 
sionally in estuarine habitats. In 
inshore waters, it has been observed 
to depths of 60 m and is known to 
travel long distances across open 
waters (International Union for 
the Conservation of Nature [IUCN] 
Red List of Threatened Species, 
vers. 2011.2 [Available from http:// 
www.iucnredlist.org/apps/redlist/de- 
tails/39415/0, accessed July 2011]). 
The spotted eagle ray is a benthic 
feeder with a diet consisting mainly 
of bivalve and gastropod molluscs 
(Randall, 1967, for A. narinari ; 
Schluessel et al., 2010b for A. ocella- 
tus), but it also consumes cephalopods, 
crustaceans, and teleost fishes. It is 
found to be solitary or to swim in 
large schools of up to several hundred 
individuals (McEachran and de Car- 
valho, 2002). 
Little is known about the biology 
and reproduction of A. narinari. Indi- 
viduals reach large sizes, and if the 
distance between both extremes of 
the pectoral fins or disc width (DW) 
is used as a measure of length, the 
maximum reported length is 230 cm 
DW; most reported individuals, how- 
