Table 8. — Percentage frequency of occurrence (adjusted for the difference in numbers of temperature and salinity observations in each 

 range) of the most plentiful zooplankton at three salinity and temperature intervals, each of uhich includes about an equal number of 

 observations — Tampa Hay and the adjacent Gulf of Mexico. September 1.961 through August 1962 



Taxon 



Total 

 occurrences 



Annelida: 



Terebellidae 



Spionidae 



Artliropoda: 



Lucifer faxoni 



Brachyura. 



Porccllanidae 



Copepoda.- 



Palaemonidae 



Alpheidue 



Stoniatopoda 



llippolytidae 



Thahissinidea 



Amphipoda 



Isopoda 



I'enaeidae 



Chaptopnatha: 



.^agitta hispida 



.'<agilla. spp.^ 



('hordata: 



Fish oges- 



Appendlculariidae 



Engraulidae 



Sciaenidae 



Clupeidae. 



Syngnatheidae 



No. 



47 

 42 



233 



223 



216 



177 



158 



116 



89 



85 



79 



48 



35 



26 



133 



107 



85 

 83 

 SO 

 42 

 39 

 28 



Temperature (° C.)' 



12.8-20.9 



(89) 



Percent 

 16.6 

 30.8 



29.6 

 28.1 

 30.S 

 33.2 

 31.6 

 25.8 

 25.7 

 24.4 

 21.3 

 39.8 

 31.7 

 3.6 



32.8 

 26.6 



37.7 

 31.2 

 13.8 

 43.0 

 60.6 

 24.8 



21.0-27.9 

 (96) 



Percent 

 27.0 

 30.7 



34.6 

 33.6 

 32. S 

 30.2 

 33.3 

 34.2 

 34.3 

 29.0 

 32.5 

 35.1 

 43.0 

 16.9 



29.1 

 24.6 



31.6 

 31.1 

 32.9 

 31.1 

 36.6 

 29.5 



28.0-32.0 

 (82) 



Percent 

 56.4 

 38.5 



35.8 

 38.3 

 37.0 

 36.6 

 35.1 

 40.0 

 40.0 

 46.6 

 46.2 

 25.1 

 25.3 

 79.5 



38.1 



30.7 

 37.7 

 53.3 

 25.9 

 2.8 

 45.7 



Salinity (%„)■ 



19.0-29.4 



(90) 



Percent 

 23.0 



27.6 

 28.8 

 31.6 

 33.0 

 30.0 

 23.0 

 26.7 

 23.2 

 32.6 

 22.6 

 62.6 

 19.0 



20.0 

 23.1 



13.9 

 20.2 

 45.6 

 18.8 

 10.0 

 24.7 



29.5-33.4 



(89) 



Percent 

 19.1 

 45.3 



36.4 

 34.0 

 31.9 

 32.7 

 36.7 

 34.4 

 30.2 

 43.5 

 34.2 

 43.7 

 25.9 

 11.6 



39.0 

 32.6 



35.1 

 36.0 

 32.1 

 42,7 

 53.8 

 39.2 



33.5-36.0 



(88) 



Percent 



.17.9 

 24.1 



36.0 

 37.2 

 36.5 

 34.3 

 33.3 

 42.6 

 43.1 

 33.3 

 33.2 

 33.7 

 11.5 

 69.4 



41.0 

 44.3 



51.0 

 43.8 

 22.3 

 38.5 

 36.2 

 36.1 



' Total number o( temperature and salinity observations witliin each range sliown in parcntlieses. 

 ' Immature Sagitltt \ess tlian 5 mm. long. 



pressed as percentage frequency of occurrence. 

 Seventeen of the taxa occurred most frequently 

 at the highest range, one at the intermediate 

 range, and four at the lowest range. These ob- 

 servations suggest that for most zooplankton 

 low temperatures were more restrictive than 

 high. 



SALINITY 



The study of the relation of salinity to the 

 occurrence of zooplankton was similar to that 

 for temperature. The salinity ranges used were 

 19.0 to 29.4 p.p.t.. 29.5 to 33.4 p.p.t., and 33.5 

 to 36.0 p.p.t. (table 8) . Eleven of the 22 taxa 

 occurred most frequently at the highest range, 

 nine at the intermediate range, and two at the 

 lowest range. These comparisons suggest that 

 low salinity restricts the distribution of zoo- 

 plankton in Tampa Bay. 



The zooplankton included both euryhaline 

 and marine forms. Lucifer faxoni, porcellanids, 

 copepods, and chateognaths were taken 

 throughout the entire .salinity range (19.0 to 

 36.0 p.p.t.). The range for L. faxoni was sim- 

 ilar to the range (19.3 to 34.2 p.p.t.) given by 

 Woodmansee (1958) in Biscayne Bay, Fla. 



ACKNOWLEDGEMENTS 



Bonnie Eldred of the Florida Board of Con- 

 servation and Delores E. Dimitrious of the 

 Marine Laboratory, Institute of Marine Sci- 

 ence, University of Miami, helped identify 

 larval penaeid shrimp; Thomas E. Bowman 

 and Raymond B. Manning of the U.S. National 

 Museum, Smithsonian Institution, helped iden- 

 tify and verified the .sergestids and larval 

 isopods; and Sheldon Dobkin of Florida At- 

 lantic University, Boca Raton, Fla., and 

 Anthony J. Provenzano, Jr., and Anthony Rice 

 of the In.stitute of Marine Science, University 

 of Miami, helped identify caridean, pagurid, 

 and thalassinid crustaceans. At the Bureau of 

 Commercial Fisheries Biological Laboratory, 

 St. Petersburg Beach, Fla., .John L. Taylor 

 identified polychaetes, and John H. Finucane 

 and Gordon R. Rinckey identified fish larvae. 



LITERATURE CITED 



Davis, Charles C. 



1947. Two nionstrilloids from Biscayne Bay, 

 Florida. Trans. Amer. Miscroscop. Soc. 66(4): 

 390-395. 



220 



U.S. FISH AND WILIFE SERVICE 



