84 



Fishery Bulletin 89(1), 1991 



50 

 40 

 30 

 20 



30 50 70 90 110 



50 70 90 110 



Carapace length (mm) 



Figure 6 



Size-frequency distribution of Panulirus 

 argus caught in each sampling zone during 

 the 1985 tagging operation in Bahia de la 

 Ascensi6n. 



log-likelihood ratio, indicating that it was 

 valid to pool the data over the two years, 

 i.e., there was no difference in growth 

 between years. However, combining the 

 male and female data led to a significant 

 increase in the log-likelihood ratio, in- 

 dicating different growth rates for males 

 and females. Males grew faster and 

 larger than females, similar to other 

 panulirid species (Kanciruk 1980). The 

 final set of data is shown in Table 2c. 

 Estimated mean growth curves for males 

 and females, combined for both years, are 

 shown in Figure 9. 



The algorithm also predicts the age at 

 which each animal was initially caught. 

 The estimated non-parametric density 

 function of age at first capture for the 

 1985 and 1986 data showed a clear mode 

 around 525 days from settlement. 



Growth of the lobsters in Bahia de la 

 Ascension was rapid. Males and females 

 enter the fishery at 74 mm CL, 1.65 and 

 1.7 years, respectively, after settling. 

 Allowing for a six-month larval period 

 (Lewis 1951), males and females enter 

 the fishery at approximately 2.15 and 2.2 

 years of age, respectively. 



The analysis of mean weekly growth 

 rates (Hunt and Lyons 1986) combining 

 the 1985 and 1986 data (not illustrated) 

 did not show any points of inflection, sug- 

 gesting that there is no marked decrease 

 in the growth rate of the lobsters in the 

 bay. 



Movements 



Most of the recaptured lobsters were 

 caught within the boundaries of the coop- 

 erative's fishing ground. Lobsters that 



Figure 7 



Size-frequency distribution of Panulirus 

 argiis caught in sampling zones II, III, IV, 

 and VI during the 1986 tagging operation in 

 Bahia de la Ascensi6n. 



