Table 4. — Weekly fishing effort for bait shrimpers in Old Tampa Bay, 

 December 4, 1961, through April 8, 1962 



Weekly average. 



Maturity 



Among bait shrimp sampled during this 

 survey, males were more often mature than 

 females, and apparently became mature at a 

 smaller size than females. Eldred (1958) found 

 that male pink shrimp nnatured at 75 mm. 

 total length and fennale pink shrimp became 

 impregnated at 91 mm. total length. Cummings 

 (1961) estimated the carapace length of about 

 22 mm. for female pink shrimp at first sexual 

 maturity. Sexual maturity of males is based 

 on a criterion (both petasma endopods joined) 

 given by Eldred (1958). 



Old Tampa Bay appears to be one of the 

 main nursery areas for young pink shrimp 

 in Tampa Bay. 



The size of 1,2 38 pink shrimp caught by 

 Eldred et al. (1961) near Big Island in Old 

 Tampa Bay in 1957 and 1958 had a mean 

 total length of 62 mm, and 56 mm. for those 

 2 years. These sizes indicate that most of the 

 shrinnp were immature and were using the 

 area as a nursery. Most of the female shrimp 

 caught in Old Tannpa Bay during the present 

 survey were also young and unimpregnated 

 (81.7 mm. total length). The mean size of the 

 males (79.2 mm.), however, indicated that a 

 higher proportion of males was mature. These 

 shrimp probably reach maturity in the Bay 



before they migrate into the Gulf of Mexico, 

 Eldred et al. (1961) found that larger shrimp 

 (85-140 mm. total length) migrated from 

 estuarine areas in April through July. They 

 also reported an abundance of pink shrimp 

 caught by commercial shrimp boats offshore 

 from Tampa Bay in the early summer of 1958, 

 I observed commercial boats trawling there 

 in March and April 1963, 1964, and 1965. 

 The catches may have been of shrimp migrat- 

 ing from Tampa Bay and other estuaries in 

 the vicinity, because there was no apparent 

 shrimping offshore from Tampa Bay other 

 than in March and April. 



Length and Weight 



The bait shrimp fronn lower Tannpa Bay 

 averaged longer (by about 0.5 mnn. carapace 

 length and 2.0 mm. total length), and heavier 

 (0,5 g,) than those fronn Old Tampa Bay 

 (tables 6 and 7). Females were larger and 

 heavier than males in all but one sample- - 

 they averaged 0.8 mm. carapace length and 

 2,0 mm, total length longer and 0.6 g. heavier 

 than males. Females also outnumbered males 

 in the larger size classes (figs. 3-5). 



The ranges and means of the carapace length, 

 total length, and total weight taken from each 

 weekly sample should not be considered 



