Occurrence of Larval, Juvenile, and Mature Crabs in the 

 Vicinity of Beaufort Inlet, North Carolina 



By 



DONNIE L. DUDLEY and MAYO H. JUDY 

 Fishery Biologists 



Center for Estuarine and Menhaden Research 

 Beaufort, North Carolina 28516 



ABSTRACT 



Monthly samples from 13 ocean stations near Beaufort Inlet, N.C., were examined for 

 the occurrence of crab larvae in 1962. Larval collections were supplemented by sam- 

 pling with a bottom trawl for juveniles and adults in 1962 and 1963. Trawling was 

 restricted to a small area near the sea buoy at the Inlet. Larvae of 27 species of crabs 

 were taken during the study and were most abundant during the summer and fall. 

 Adults of 13 species of crabs occurred in the collections, with Callinectes sapidus, C. 

 similis, Portimus gibbesii, Ovalipes ocellatus, and Hepatus epheliticus being the more 

 prevalent. 



INTRODUCTION 



During 1962 and 1963, as a part of the blue 

 crab studies at the National Marine Fisheries 

 Service Laboratory, Beaufort, N.C., plankton 

 samplers and bottom trawls were fished off- 

 shore to determine the seasonal distribution 

 and abundance of various crab stages. Plank- 

 ton stations were sampled twice a month from 

 May through November 1962, and bottom 

 trawl samples for juvenile and adult crabs 

 were taken twice a month from June 1962 

 through December 1963. The study provided 

 information on the species present and their 

 time of spawning. Also, our knowledge of 

 the size of the crab populations was increased. 



SAMPLING STATIONS AND 

 TECHNIQUES 



Larvae were collected in the ocean at 13 

 plankton stations in an area extending approx- 

 imately 8 km east and west of the Beaufort 



Inlet and 13 km offshore (Figure 1). Stations 

 1, 2, 5, 6, 9, and 10 were approximately 1.6 km 

 offshore and stations 3, 4, 7, 8, and 11 were ap- 

 proximately 6.5 km offshore. Stations 12 and 

 13 were 10 and 13 km offshore, respectively. 

 Stations were located about 4 km apart on an 

 east-west axis. Two samples were collected 

 twice a month at each station, one at 1 m and 

 the other at 8 m below the surface. Two 127-mm 

 diameter Clark-Bumpus plankton samplers, 

 equipped with nylon net with 526-/* mesh 

 openings and a cap with 390-yu. mesh openings, 

 were used for sampling. Samples were collected 

 by fishing the two samplers simultaneously for 

 10 min. The samples were preserved in 2% 

 formaldehyde in 120-ml jars. Three 4-ml ali- 

 quots of each sample were examined for crab 

 larvae. 



Two 30-min hauls with a 8.5-m otter trawl 

 were made twice a month near the sea buoy 

 (Figure 1, station 3) in 11 to 14 m of water. 

 The trawl was constructed of nylon netting 

 with 22-mm mesh (bar measure) in the body 



