generalized manner. In the aquatic 

 sector, trophic relationships follow 

 those of Odum (1971) though modified 

 somewhat to conform to the expanded 

 setting. Primary and secondary con- 

 sumers correspond to what Odum 

 calls "mixed trophic levels" (her- 

 bivores, omnivores, and higher car- 

 nivores). Data on the food habits 

 of mangrove fish and wildlife are 

 extensively summarized in Odum 

 et al. (1982). 



7.32 INVERTEBRATES 



Unlike the terrestrial and 

 freshwater wetlands invertebrates, 

 those of the estuarine zone are a 

 more often studied component of the 

 wildlife. Nonetheless, there are 



still major gaps in both basic spe- 

 cies lists and the ecology of known 

 residents. 



Odum et al. (1982) divide in- 

 vertebrates into three (3) communi- 

 ties: the arboreal arthropod commu- 

 nity, the prop root and associated 

 mud surface community, and the water 

 column community. To this list one 

 should add the salt marsh and salt 

 prairie communities, as well as the 

 beach and dune community. Unfortu- 

 nately, information is severely 

 lacking on these latter two habitats 

 within the study area. 



By far the most frequently 

 studied invertebrate community is 

 the water column. Notable studies 

 include the work of Tabb and Manning 

 (1961) and Tabb et al. (1962) in 

 Whitewater Bay, Davis and Williams 

 (1950) in the embayments and brack- 

 ish lakes fringing northern Florida 

 Bay, McPherson (1971) in the Shark 

 River estuary, and Odum (1971) in 

 the North River estuary. For indi- 

 vidual species lists the reader 

 should consult these sources. In 

 the following account only a brief 



summary of the more salient features 

 of these studies is presented. 



Salinity appears to play the 

 major role in determining inverte- 

 brate assemblages within the study 

 area. For instance. Figure 53 (from 

 McPherson 1971) shows salinity pre- 

 ferences for 12 species of zooplank- 

 ton along the length of the Shark 

 River estuary. Three additional 



species, including the most abundant 

 zooplankton Acartia tonsa , are also 

 shown on this figure. The latter 

 was generally always dominant be- 

 tween salinities of 0.4 to 22 ppt. 



Some species of crustaceans 

 also show rather distinct salinity 

 zonation. Three species of prawns 

 Paleomonetes paludosus , P. puqio , 

 and P. intermedius follow a consis- 

 tent relative distribution to one 

 another based on preferences for in- 

 creasing salinity range. A similar 

 distribution is recorded for three 

 mysids Taphromysis bowmani , Mysi- 

 dopsis almyra , and Gastrosaccus 

 disimilis (McPherson 1971). 



In addition to the salinity 

 factor, Davis and Williams (1950) 

 suggest that isolation of brackish 

 embayments along the northern fringe 

 of Florida Bay is also a factor in 

 determining plankton assemblages. 

 Two close but isolated lakes showing 

 very similar salinities exhibit 

 reverse relative abundances of roti- 

 fers and pelecypod veligers. In 

 Long Lake, Davis and Williams (1950) 

 report Cyclops permamensis tannica 

 as the dominant copepod over Acartia 

 floridana 95% to 5% in numbers in 

 1947, while only A. floridana was 

 found in 1948. A. tonsa and Temora 

 sp. were reported from the open 

 waters of Florida Bay. A. floridana 

 was apparently confined to the clos- 

 ed waters and replaced by A. tonsa 

 in the more open waters. 



154 



