146 
Fishery Bulletin 1 14(2) 
Table 1 
Biological measurements of the bullnose ray (Myliobatis freminvillei) caught by the artisanal fishery of La Pared, Margarita 
Island, Venezuela, during 2 periods: 2005-2007 and 2013. Average disc widths (DWs) and average weights are given with 
standard deviations (SDs). An asterisk (*) indicates statistical differences at level of significance (a) of 0.05. 
Year 
2005 
2006 
2007 
2013 
All years 
n 
14 
33 
91 
49 
187 
Number of females (F) 
2 
10 
42 
31 
85 
Number of males (M) 
12 
23 
49 
18 
102 
Sexual ratio (F:M) 
1:5* 
2:5* 
9:10 
17:10* 
4:5 
DW intervals (F) (cm) 
40.8-50.5 
24.0-82.4 
26.4-96.0 
54.4-93.5 
24.0-96.0 
Weight intervals (F) (kg) 
1.0-1. 8 
0.2-7. 4 
0.3-12.0 
2.2-10.6 
0.2-12.0 
DW intervals (M) (cm) 
42.0-56.4 
45.0-60.2 
22.8-118.0 
37.6-86.5 
22.8-118.0 
Weight intervals (M) (kg) 
1.0-2. 8 
1. 3-3.0 
0.2-19.0 
0.6-8. 6 
0.2-19.0 
Average DW (cm) 
51.9 (SD 4.4) 
56.2 (SD 10.0) 
58.5 (SD 16.0) 
69.4 (SD 13.3) 
60.0 (SD 15.0) 
Average weight (kg) 
2.0 (SD 0.5) 
2.7 (SD 1.7) 
3.4 (SD 3.1) 
5.1 (SD 2.8) 
3.4 (SD 2.8) 
First gravid (cm) 
- 
- 
75.8 
84.6 
75.8 
Immature (%) 
50 
33 
18 
10 
25 
Gravid (%) 
0 
0 
1 
1 
1 
DW 100% maturity (cm) 
>54.0 
>54.0 
>54.0 
>55.0 
>55.0 
Maximum fecundity 
- 
- 
1 
6 
6 
Maximum DW embryo (cm) 
— 
9.0 
20.6 
20.6 
Disc width (cm) 
Figure 1 
Frequency distribution of disc-widths of male and female bullnose ray ( Myliobatis fremin- 
villei ) caught in the artisanal fishery of La Pared, Venezuela, during 2 periods: 2005-2007 
and 2013. 
provided a total yield of 648.1 kg of the bullnose ray. 
The estimated overall CPUE was 0.8 individuals/trip 
(standard deviation [SD] 1.3) or 2.9 kg/trip (SD 5.5). 
Differences in the number of trips, individuals, and 
kilograms of catch were observed over the years sam- 
pled. In 2013, the number of trips reached a maxi- 
mum, but that peak occurred without a concomitant 
increase in the number of kilograms or animals cap- 
tured. Monthly analysis showed a higher level of fish- 
ing effort during April-June 2013 in comparison with 
previous years, although there were high numbers of 
trips with no catches of the bullnose ray (Fig. 2A). 
