810 



Fishery Bulletin 91(4). 1993 



Table 2 



Catch composition of Panulirus argus caught on the shelf 

 outside Bahia de la Ascension during the exploratory fishings 

 with traps (summer 1989 and winter 1989-1990), and of those 

 obtained from beneath casitas in the bay during May^June 

 1986 (M=males, F=females, CL=carapace length in mm). 



Offshore 



Summer 



Winter 



N 



Male: Female 

 Mean CL, F. 

 CL range, F. 

 Mean CL, M. 

 CL range. M. 



67 

 1.31:1 

 89.3 



55.0-156.9 

 111.0 



76.5-162.1 



395 



1.04:1 



78.9 



52.4-117.2 



88.7 

 56.0-134.0 



Bay" 



1402 



1.04:1 



64.4 

 22.0-100.3 



65.9 

 29.8-113.1 



Data from Lozano-Alvarez et al. ( 1991a). 



Table 3 



Percentage of Panulirus argus in each of the four carapace 

 states, caught on the shelf outside Bahia de la Ascension 

 during the exploratory fishings with traps (summer 1989 and 

 winter 1989-1990), and of those obtained from beneath casitas 

 in May-June 1986. Carapace states 1-4 represent a range 

 from neA'ly molted and completely clean to heavily fouled. 



Carapace 

 state 



Offshore 



Summer 

 (A r =67) 



Winter 

 (N=395) 



Bay 



(^=1402) 



non-parametric Mann-Whitney £/-test with normal ap- 

 proximation (Zar, 1984). The level of significance con- 

 sidered throughout this paper is P = 0.05. 



Results 



Size structure and catch composition of 

 lobsters on the shelf outside the bay 



A total of 462 lobsters, 239 (52%) males and 223 (48%) 

 females, were caught during fishing operations out- 



side the bay. The observed sex ratio was not signifi- 

 cantly different from the expected value <x 2 =0.554, 

 df=l). Males were significantly larger than females 

 U=25.06, df=460, P<0.001). Mean CL for males was 

 92.2 mm (range: 56.0-162. 1 mm ) and for females was 

 80.4mm (range: 52. 4-156. 9mm). 



Of the total catch obtained outside the bay, only 67 

 individuals (29 females and 38 males) were caught 

 during the summer, while 395 (194 females and 201 

 males) were captured in the winter. Abundance of lob- 

 sters on the shelf outside the bay, expressed as num- 

 ber of lobsters per trap-lift, was significantly higher 



