Duarte et al: Relative growth, population structure, and reproductive biology of slipper lobsters (Scyllaridae) 
61 
40.5% (in December) to 83.3% (in November), indepen- 
dent of the fishing gear used, and higher levels were 
recorded in trawls (84.2%) during the spring and in 
pots and traps (72.6%) during the winter. 
Size (TL) composition showed significant monthly 
variation, regardless of sex (P<0.001), with greater dif- 
ferences between the monthly means for males (from 
23.6 cm TL [standard deviation (SD) 3.4] in August to 
19.6 cm TL [SD 2.8] in October) than for females (from 
24.5 cm TL [SD 4.1 in May to 21.7 cm TL [SD 4.9] 
in November). No significant seasonal differences were 
observed in the size composition for each sex (P=0.14) 
or in the sex ratio of hooded slipper lobster (P>0.05). In 
general, the sex ratio of hooded slipper lobster (Table 
3) did not differ significantly from a proportion of 1:1 
(P>0.05), regardless of the fishing gear used (P=0.85). 
However, males predominated in smaller length classes 
(11.0-24.0 cm TL) and females in larger sizes ( >24 cm 
TL). The t-test confirmed that females tended to be 
larger than males (males: 21.9 cm TL [SD 3.0]; females: 
23.9 cm TL [SD 3.7]; PcO.OOl). 
The spatial distribution of the fishing areas for both 
fleets (areas 1-5; Fig. 4; Table 2) showed that the dou- 
ble-trawler fleet that caught Brazilian slipper lobster 
operated farther south (between the latitudes 25°00'S 
and 26°24'S) than the pot-and-trap fleet, at depths of 
40-165 m, and particularly in areas 1 and 4. On the 
other hand, the pot-and-trap fleet concentrated fishing 
efforts in shallower waters (at depths of 43-100 m), be- 
tween the latitudes 24°00'S and 25°00'S, and operated 
preferentially in area 2. 
The males from area 5 were significantly smaller 
than those caught in areas 2 and 4 (P<0.01) (Fig. 5). 
Females from area 5 also were smaller than females 
caught in areas 3 and 4 (P<0.05). The proportion 
of immature females among the adults caught in 
the trawl fleet ranged from 55% (area 4) to 90% 
(area 3), whereas, in the pot-and-trap fleet, the 
percentages of immature females were between 
56.5% (area 2) and 75.9% (area 3). 
In all fishing areas, males caught by double 
trawlers had a lower median size (20.7 cm TL) 
than males captured in pots or traps, and small- 
er individuals were observed in area 3. Females 
were more abundant in area 1 (% 2 : P=0.036), and 
males were more abundant in area 2 (% 2 : P=0.01). 
Carapace color was used to classify 871 speci- 
mens of the hooded slipper lobster. The 7 cate- 
gories evaluated were ranked in descending or- 
der (the absolute frequency for each category is 
shown in parentheses): D(259) > DR(247) > L( 108) 
> R(103) > LR(91) > 1(37) > M(26). The posteriori 
multiple comparison conducted with Tukey’s test 
revealed significant differences between some of 
the color patterns for males (patterns: R?tL, I, and 
M; P<0.05) and females (patterns: R^L, I, LR, and 
M; PcO.OOl). The R pattern showed the smallest 
variation (by size [TL]) and was characteristic of 
smaller individuals (mean: 21.5 cm TL [SD 2.7]), 
regardless of sex (Fig. 6). In addition, all females with 
this carapace color (n= 8, 27.6% of immature females) 
were identified by dissection as juveniles, and the other 
color patterns were found on both juveniles and adults. 
Therefore, an association between R pattern and a rel- 
atively narrow range of TLs was verified for both sexes. 
This relationship was not affected by the sex of the 
lobster, fleet composition (despite differences in storage 
of catch), month of capture, or fishing area. 
Discussion 
For the hooded slipper lobster, the r 2 values for mor- 
phometric relationships showed an excellent linear cor- 
relation. Females tended to show an increase in LA, 
therefore, enhancing their capacity for oviposition and 
for hatching a greater number of eggs in the bristles 
of their pleopods (individual fecundity) (Stewart et ah, 
1997; Demartini and Williams, 2001; Oliveira et al., 
2008). Although the average female is larger than the 
average male, it is possible that an increase in body 
size (TL) in males facilitates the selection, grasping, 
and manipulation of females at the time of copulation, 
as has been observed in lobsters of the genus Panulirus 
(Lavalli and Spanier, 2007). Therefore, in general, sig- 
nificant differential growth was not observed between 
the juveniles and adults of each sex, nor was there ob- 
vious sexual dimorphism, although there was a small 
investment of energy in the width and length of the ab- 
domen in females and in the carapace length for males 
in larger animals ( >25 cm TL). 
Various biometric equations presented high values 
of r 2 and thereby reinforced their suitability for use in 
