BROWN SHRIMP 



The most extensive data on brown shrimp 

 were obtained in Georgia, where sannpling 

 was done regularly on both inside and outside 

 shrimp grounds from 1931 to 1933. The study 

 was extended in 1933 to include outside fishing 

 grounds in South Carolina and northeast Flor- 

 ida (Anderson, 1968). 



At the time these records were made, all 

 grooved shrinnp were included under one spe- 

 cies, Penaeus brasiliensis . This species was 

 later split into three species to include brown 

 shrimp, P. aztecus; pink shrinip, P. duorarum ; 

 and P^. brasiliensis . Of these three forms, 

 P. brasiliensis rarely occurs in the shallow 

 coastal shrimping grounds of the south Atlantic 

 coast, the brown shrinnp is fairly abundant in 

 all four States, and the pink shrimp is abundant 

 only in North Carolina. 



Pink shrimp are seldom captured in the 

 narrow coastal strip to which the regular 

 shrimp fishery in South Carolina and Georgia 

 is largely confined. Lunz (1963) did not report 

 the capture of any pink shrimp during a 2-year 

 shrimp survey in South Carolina from July 

 I960 to June 1962; and Bearden (1961) stated 

 that, "P. duorarum is not at all common in 



South Carolina waters " Frisbie (1967), 



reporting on a shrimp survey from July 1966 

 to June 1967 in Georgia, stated, "Pink shrimp, 

 Penaeus duorarum . were taken only occa- 

 sionally throughout the year." Joyce (1965), 

 reporting on a survey of the commercial 

 shrimps of the northeast Florida coast from 

 St. Marys Inlet to Cape Kennedy during July 

 1962 to June 1963, reported that he captured 

 only 264 pink shrimp in the outside or offshore 

 waters. He also indicated that the major 

 grounds for adult pink shrimp probably lie 

 farther offshore and in deeper water than the 

 regular shallow coastal shrimping grounds. 

 The occasional pink shrimp that may be in- 

 cluded as brown shrimp in my 1 93 1-35 records 

 are too few to be significant. 



Georgia 



Brown shrinnp appear on the Georgia shrimp- 

 ing grounds in May or June, but usually in 

 June. They reach greatest abundance in July 

 and August, decline rapidly in abundance dur- 

 ing September (fig. 5), and have largely dis- 

 appeared from the fishery by October (in some 

 years a few remain until November). There- 

 fore, data in significant announts are confined 

 to June, July, August, and September. 



Size distribution .-- The length of brown 

 shrimp from inside grounds (sounds and rivers ) 

 increased gradually with the progress of the 

 fishing season (fig. 7). Modes of 103 to 108 mm. 

 for males and 118 to 123 mm. for females in 



68 78 88 98 108 118 128 138 148 158 168 178 

 63 I 73 r 83 I 93 I 103 | 113 I 123 | 133 I 143 j 153 f 163 | 173 I 183 



7 

 6 

 5 

 4 

 3 

 2 

 1 





 11 

 10 

 9 

 8 

 7 

 6 

 5 

 4 

 3 

 2 

 1 





 13 

 12 

 11 



z'" 



U 8 



0« 7 



5 



I 73 I 83 1 93 I 103 l 113 | 1 23 I 133 I 143 I 153 r 163 | 173 I 

 I ' I I I I I I I I I I I I I I I I I ' I ' I 



JUNE 



- 984 MALES =50.5%, 



- 974 FEMALES -49.9%_ 



I > I ■ I ■ I I I I I I I ' I > I > I I 



AUGUST 



— 1,034 MALES =52,6% 



933 FEMALES =47,5%. 



SEPTEMBER 

 ■ 250 MALES = 75,2 % 

 • 82 FEMALES - 24,6 % 



.III , , 



63 73 ' 83 ' 93 ' 103 ' 113 ' 123 ' 133 ' 143 ' 153 ' 163 ' 173 ' 183 

 68 78 88 98 108 118 128 138 148 158 168 178 



TOTAL LENGTH (MM) 



Figure 7. — Size distribution and sex ratios of brown 

 shrimp on Georgia inside fishing grounds by month, 

 June to September, 1931-34. 



June increased steadily to 133 mm. for nnales 

 and 158 mm. for females by September. It is 

 difficult to link this size increase with growth 

 rates because snnall shrimp were continuously 

 being recruited onto the grounds and some of 

 the larger shrimp were moving to outside 

 waters. 



