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Fishery Bulletin 1 10(3) 
15% of trips. CPUE in excess of 13 individuals per trip 
occurred only between February and May. 
CPUE in weight (kilograms) of fish caught per trip 
(Fig. 2B) showed a decreasing trend during 2006 but 
was much more stable in 2007, albeit with a decreas- 
ing trend during the first 6 months. The months with 
the minimum and maximum values of CPUE by weight 
were the same months for which the highest and lowest 
CPUE in numbers of fish per trip was observed. The 
overall mean CPUE for the study period was 133 kg per 
trip. The average weight of individuals caught during 
the 29-month sampling period was 41.9 kg, and peaks 
in weight occurred in the second and last quarters of 
each year of study. 
Length structure and length-weight relationships 
Measurements of length (DW in centimeters) were taken 
from 321 males and 846 females. Both sexes showed 
a unimodal length-frequency structure (Fig. 3A), and 
the overall range of observed lengths was 64-226 cm 
DW. The largest observed male was 190 cm DW. Males 
larger than 160 cm DW represented less than 10% of 
the sample. Females reached greater lengths, and the 
largest observed individual was a gravid female at 226 
cm DW. Approximately 42% of females were larger than 
160 cm DW. 
Measurements of length and weight were taken from 
105 males and 185 females. The comparison of male and 
female length-weight relationships showed no statisti- 
cally significant differences (F=1.87; P=0.16). There- 
fore, a single length-weight relationship for both 
sexes was estimated (Fig. 3B). Point estimates and 
confidence intervals for intercept (a) and exponent 
( b ) of this relationship were 1.824xl0 -5 (9.6xl0 -6 - 
3.4xl0~ 5 ) and 2.95 (2.82-3.07), respectively. 
Sex ratio and reproductive period 
Of 321 males, 127 were immature and 194 were ma- 
ture. Males were absent in the sampled catch during 
November 2005; August-December 2006; and June, 
September, and November 2007. Mature males were 
observed in all remaining months, except October 
2005 (Table 1). 
Of the 846 female individuals examined, 481 were 
immature, 242 were mature nongravid, 61 were 
gravid, and 62 were postgravid. Females were ob- 
served in different maturity stages in all months 
of the study period, except in November 2007, when 
all were found to be immature. November 2007 also 
was the month with the smallest sample size ob- 
tained during this study (n = 3). Postgravid individu- 
als, indicating recent parturition, were present in 
August 2005, February-May and July-September 
2006, January-April and July-October 2007, and 
December 2007 (Table 1). 
Fecundity and embryo lengths 
Of the 61 gravid females, 75% had 3-5 embryos, 
and the remaining 25% of gravid females had 1-2 
embryos. Seven individuals exhibited the maximum 
observed fecundity of 5 embryos within the uterus. 
Mean overall fecundity and standard deviation (SD) 
was estimated at 3.09 (SD = 1.31) embryos. No signifi- 
cant relationship was observed between female length 
and the number of embryos for a sample of 35 gravid 
females (F= 2.29; P=0.14). 
The largest numbers of embryo samples were ob- 
tained in February 2006 (n = 13), May 2006 (/; = 8), 
February 2007 (n= 22), and July 2007 (n- 9). Of 80 
embryos observed, the length ranged from 10.1 to 44.5 
cm DW (mean=31.5 cm DW) (Table 1). Eight embryos 
