Carmona Suarez and Conde: Distribution and abundance of Callinectes spp and Arenaeus cribrarius 



17 



Arenaeus cribrarius 



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T — I — I — I — I — I — I — I — I — I — I — I — V — I — I I I I r 



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 I 1993 II 19 94 1 



Sampling months 



Figure 4 



Abundance of Arenaeus cnbranus, Callineclcx danae, and total captured crabs in 

 Ensenada de La Vela (Falcon. Venezuela). 



not appear at night. Arenaeus cribrarius was the domi- 

 nant species followed by C. danae, during both diurnal 

 and nocturnal samplings, whereas C. maracaiboensis, C. 

 bocour-ti. C. larvatus, and C. sapidus were present in very 

 low numbers. Guild composition did not differ significantly 

 between day and night (G=1.630; 0.90>P>0.50; df=5), nor 

 did the average number of individuals per trawl (0.86 vs. 

 0.62; <=1.702; 0.10>P>0.05: df=262 ). In both dominant spe- 

 cies, A. crib>-ariu!i and C. danae. the average size of crabs 

 caught during daylight hours (Table 5) did not differ sig- 

 nificantly from those collected at night, nor did the size 

 frequency distributions (G=3.820; df=4; 0.50>P>0.10). Sex 

 ratios of these two species did not show significant diel 

 differences either (G=0.030: 0.90>P>0.50; df=l; G=2.750; 

 0.50>P>0.10: df=l. respectively). 



Offshore A total of 64 crab pots were deployed. 32 during 

 each period. Four species were caught during both day and 

 night (C. hocourti, C. maracaiboensis, C. ornatus, and C. 



danae I. A total of 89 crabs were caught during the day 

 and 84 at night (Table 6). Callinectes bocourti comprised 

 73.8'7( and 75. 3*/? of the abundance during the day and 

 night, respectively, followed by C. maracaiboensis (15.5% 

 and 6.7%). No differences in guild composition or sex 

 ratios were found between day and night samples at each 

 of the sites (Table 6). Crab species did not show differ- 

 ences in carapace length between day and night captures 

 (C. bocourti, ^=0.704, P>0.05, df=155; C. maracaiboensis, 

 /=1.355, P>0.05, df=13; C. ornatus, ^=0.881, P>0.05, df=9; 

 C. danae, ^=1,811. P>0.05, df=10). Kolmogorov-Smirnov 

 tests run for normality of carapace length distribution for 

 species at the offshore station compared between day and 

 night samples, were statistically nonsignificant. 



Sex ratios and ovigerous females 



At the foreshore, all the species had male-biased overall 

 sex ratios (Table 7), although only yi. cribrarius, C. danae 



