§ 160 



i I i 1 1 1 1 1 1 r- 



JAN. FEB. MAR. APR. HAY JUNE JULY AUG. SEPT. OCT. NOV. DEC. 



JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. OCT. NOV. DEC. 



Figure 4. — Catch and effort of the pot fishery for blue 

 crabs of Area 1, St. Johns River, 1961-62. 



Figure 5.— Catch and effort of the pot fishery for blue 

 crabs of Area 2. St. Johns River, 1961-62. 



FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. OCT. 



Figure 6. — Catch and effort of the pot fishery for blue 

 crabs of Area 3, St. Johns River, 1961-62. 



COMPOSITION OF THE CATCH 



Commercial catches of crabs were sampled 

 in 1961 and 1962 for species composition, sex 

 ratio, carapace width, weight, and minimum 

 market size. 



Samples of approximately 150 crabs were 

 taken from unculled catches. The pot fishery 

 was sampled monthly in each of the three 

 areas throughout the year. The trawl fishery 

 was sampled when trawling for crabs was most 

 productive. Observations were made also at the 

 time the crabs were landed or at the time they 

 were sold at market to supplement or confirm 

 data obtained by sampling. Altogether, 80 

 samples (11,620 individuals) were taken from 

 catches by pots, and 12 samples (1,655 indi- 

 viduals) from catches of trawls. Sex was 

 determined, the carapace width of each crab 

 was measured and about every fifth crab was 

 weighed (2,488 individuals). The width was 

 measured in millimeters between the tips of 

 the lateral spines, and the weights were 



recorded in grams. Because there was no mini- 

 mum size limit on crabs, comparisons were 

 made between unculled catches of crabs and 

 those sold, to define better the difference 

 between the commercial marketable size and 

 the size of crabs actually caught. From April 

 through September 1961, 24 catches brought 

 to processing plants were sampled to compare 

 with 24 unculled catches obtained in the same 

 localities at approximately the same time. 



Species Composition 



The catches in Area 1 contained other species 

 of crabs, but because of their small size or 

 infrequent occurrence, they had insignificant 

 market value. The trawl catches commonly in- 

 cluded one or more noncommercial species of 

 the genus Callinectes in late spring to early 

 fall. These crabs were of the forms described 

 by Rathbun (1930) as Callinectes ornatus , 

 C. danae , and C. marginatus . Because of the 

 uncertainty of the taxonomic separation of this 



