Blue Tilapia in Georgia 



31 



Additional information about the feeding ecology, growth, and 

 reproduction of blue tilapia in estuarine waters might indicate how such 

 populations are established. Zale (1987) attributed the success of blue 

 tilapia in fresh waters of the southeastern United States to the large eggs 

 and large initial size of larvae; consequently, larval blue tilapia have 

 foraging capabilities superior to those of larval centrarchids, which are 

 smaller. The diet of blue tilapia in estuarine waters has not been 

 reported, but the diet of blue tilapia in freshwater habitats includes 

 phytoplankton, zooplankton, detritus, benthic invertebrates, and 

 macrophytes (McBay 1961, Spataru and Zorn 1978, Hendricks and 

 Noble 1979). Additional information on the biology of this species in 

 estuarine waters is necessary before the critical factors in their dispersal 

 and establishment in those habitats are understood. 



The effects of blue tilapia on native aquatic communities are not 

 well documented, but they are being reported with increasing frequency 

 as this species spreads into new habitats and increases in abundance. 

 Abundance of blue tilapia, approaching 2600 kg/ ha in some waters of 

 the United States (Noble and Germany 1976, Germany and Noble 



Size (TL) Frequency Distribution 



o 



c 



TL (mm) 



Fig. 2. Size distribution of blue tilapia collected with cast nest and minnow 

 traps. Size categories given on the abscissa indicate the lower limit of a 5-mm 

 category. 



