120 
Fishery Bulletin 115(1) 
35 n 
10 20 30 40 50 60 
■ Mates (BCS) 
im Males (CR) 
M Females (BCS) 
□ Females (CR) 
□ Unknown sex (BCS) 
□ Unknown sex (CR) 
70 80 90 100 110 120 130 140 
Fork length (cm) 
Figure 2 
Size distribution (measured in fork length) of roosterfish {Nematistius pectoralis) 
captured in Baja California Sur (BCS), Mexico, during 2010-2015 and in Golfo 
Duke, Costa Rica (CR), 2013-2014. 
Table 1 
Parameters (a and b) of the length-weight relationship of roosterfish (Nematistius 
pectoralis) captured from 2 locations, Baja California Sur (BCS), Mexico, during 
2010-2015 and Costa Rica (CR) during 2013-2014, by area and sex, and Student’s 
Gtest results for the testing of isometric growth. 
Area 
Sex 
a 
b 
t 
P 
BCS 
Males 
2.4x10-5 
2.84 
-0.18 
0.85 
BCS 
Females 
2.8x10-5 
2.81 
-0.25 
0.80 
BCS 
Sexes combined 
2.7x10-5 
2.82 
-0.25 
0.79 
CR 
Males 
2.7x10-5 
2.81 
-0.48 
0.62 
CR 
Females 
2.8x10-5 
2.81 
-0.50 
0.62 
CR 
Sexes combined 
2.7x10-5 
2.81 
-0.60 
0.54 
Combined 
Sexes combined 
2.6x10-5 
2.82 
-0.29 
0.76 
sections were overpolished, and otolith sections were 
illegible because of increasingly narrow widths of DGIs 
in older fish. 
The estimated ages of the fish assessed from Baja 
California Sur ranged from 18 d (0.05 years, 5.2 cm 
FL) to 548 d (1.49 years, 86 cm FL). The range of age 
estimates from Costa Rica was 32 d (0.08 years, 13.5 
cm FL) to 448 d (1.22 years, 78.7 cm FL). 
In most cases, it was possible to count DGIs from 
sagittal otoliths of fish <57 cm FL (the size reached 
at an age of approximately 1 year). The agreement be- 
tween the estimated ages assigned independently by 
the 2 readers revealed a CV of 9.02%, indicating a high 
consistency. The average CV for different size classes 
increased from 5.9 for fish with 18-100 DGIs to 6.8 
for fish with 101-199 DGIs and 9.5 for fish with 200- 
