CRAB LARVAE (Callinectes), IN 



PLANKTON COLLECTIONS 



FROM CRUISES OF M/V Theodore N. Gill 



SOUTH ATLANTIC COAST OF THE 



UNITED STATES, 1953-54 



by 



Paul R. Nichols and Peggy M. Keney 

 Fishery Biologists 



ABSTRACT 



During the course of nine Gill cruises, plankton was collected at 80 regular 

 stations between Jupiter Light, Fla., and Cape Hatteras, N,C., from near the beaches 

 to beyond the axis of the Gulf Stream, and from 9 special stations farther offshore. 

 Subsamples were taken from selected collections and examined for Ca llinectes 

 larvae. The presence of early stage zoeae indicated that spawning oc- 

 curred throughout the year in Florida waters, but subsided during winter months 

 in waters north of Florida. Early stage zoeae were captured at temperatures from 

 16.4° to 29.2° C, with peak numbers taken from May to November at 27.0° to 

 29.0 oc., depending on the area. Early stage zoeae occurred in abundance near 

 the beaches, advanced stage zoeae and megalops were more common offshore, while 

 combined larval stages were found in greatest numbers at the 20-mile offshore 

 stations. 



INTRODUCTION 



The identity and distribution of crabs, genus 

 Callinectes occurring along the coast of the 

 Southeastern United States are uncertain. 

 Four crabs of this genus are known to occur 

 in this area. They are C. sapidus. C. omatus. 

 C. danae, and C. l/ar^irea<us.Rathbun (1930) de- 

 scribed each of these species and reported 

 that the northern limits of their ranges are: 

 C. sapidus, Cape Code, Mass.;C. omatus, New 

 Jersey; C. danae, Indian River Inlet, Fla.; and 

 C. marginatus, the Florida Keys. Lunz (1958) 

 reported that the morphological features 

 usually given for taxonomic separation of the 

 latter three species are quite variable, and 

 individuals matching any of the frontal out- 

 lines given by Rathbun can be found in South 

 Carolina waters. Also, Lunz reported that only 

 about 30 percentof the crabs caught by trawlers 

 on the South Carolina coast are C. sapidus.The 



remainder belong to another species of 

 Callinectes, pTesumahly C. omatus (but pos- 

 sibly C. danae). Relatively large numbers of 

 C. sapidus, and pre su m ably C. omatus, are 

 taken in trawler catches on the North Carolina 

 coast. Nonselective gear catches in the St. 

 Johns River, Fla., are composed of C. sapidus 

 and C. omatus, but possibly C. danae or a 

 combination of all three Callinectes. 



Hatching and development of some 

 Callinectes species are known to occur along 

 the coastal area of the South Atlantic States. 

 Lunz (1958) reported that egg-bearing females, 

 presumably C. omatus (but possibly C. danae), 

 were trawled along the South Carolina coast 

 in May, August, and September at tempera- 

 tures ranging from 24° to 29° C, in salinities 

 between 26,5 and 30.6 parts per thousand 

 ( /{,o ). There were indications that spawning 

 took place offshore and extended over a 



