Table 1.-- Cruises of the Theodore N. Gill, with unoccupied stations listed 

 by number, South Atlantic coast of the United States, 1953-54 



Table 2. — Plankton samples examined for crab larvae, genus 



Callinectes from Theodore N. Gill cruises. South 



Atlantic coast of the United States, 1953-54 



DISCUSSION 



The spawning period, under natural con- 

 ditions, of the four CaUinecu-s species occur- 

 ring on the southeastern United States is not 

 definitely known. The occurrence of early 

 stage larvae in plankton collections from the 

 dill cruises indicates that spawning occurs 

 throughout the year (figs. 5 and 6). Based on 

 the limited range of each species as given by 

 Rathbun (1930), the early stage larvae found 

 from February to November In Florida waters 

 probably included C. sofu'dus and C. nrnatus, 

 with possibly (■■ dcuiae. The early stage larvae 

 found from April to September or from May 

 to November, depending on the area, in Georgia, 

 South Carolina, and North Carolina waters 



probably was a combination of C. soju'/ks and 

 C. orjiatiis. This, in general, may indicate a 

 difference in spawning period between areas 

 or differences among species in the same 

 area in spawning time and length of spawning 

 period. 



The temperature and salinity tolerance of 

 Callinectes larvae are uncertain. Costlow and 

 Bookout (1959) successfully hatched C. .sa()/'/»s 

 in the laboratory at temperature-salinity com- 

 binations of 20O, 250, 30° C„ and 21.1 to 

 32.0 %o. The presence of first stage larvae in 

 plankton samples from the ('ill cruises indi- 

 cates successful hatching by one or more of the 

 species over a wide range of temperatures — 

 from 18. 10 to 29.2° C, in Florida waters. 



