T.\BLE 7.- 



-Frequency of occurrence of zooplankters found in less than 10 percent of the samples fron 



Gulf of Mexico, September 1961 through August 1962 



[Number of tows shown in parentheses) 



Tampa Bay and the adjacent 



• Fall, winter, spring, and summer. 



quently 18.5 km. offshore where they accounted 

 respectively for 25 an(i 8 percent of the zoo- 

 plankters collected in that area. 



Forms identified in the samples but not in- 

 cluded in the aliquots of samples that were 

 counted were : the euphausiacean (Euphausia 

 americana) ; cumacean {Oxyii7-ostilis sp.) ; 

 decapods (ScyUarns sp., Emerita talpoida, and 

 Dromidia antillensis) ; lancelet {Brachiostoma 

 caribeum) ; larval fish (Strongilura timucu, 

 and Prionotus sp.) ; and polychaetes (Nereis 

 sp., Platynereis dumerilii, and Poecilochaetus 

 johnsoni) . The present collection represents 

 the first record of larval P. johnsoni from the 

 southeastern United States (Taylor, 1966). 



OCCURRENCE OF ZOOPLANKTON IN 



RELATION TO TEMPERATURE 



AND SALINITY 



TEMPERATURE 



To relate water temperature with the occur- 

 rence of the most plentiful zooplankton — 22 

 taxa accounting for 98 percent of the total 

 number of zooplankters collected — the tem- 

 perature data were divided into three ranges 

 (12.8° to 20.9° C, to 21.0° to 27.9° C, and 

 28.0° to 32.0° C), each of which included 

 about an equal number of temperature observa- 

 tions (table 8). Occuri'ences of plankton were 

 adjusted for the differences in numbers of tem- 

 perature observations in each range and ex- 



MACRO-ZOOPLANKTON IN TAMPA BAY AND ADJACENT GULF 



219 



