McBride et al.: Nursery habitats for Elops saurus 
455 
Indian River 
Zone A (n=346) 
I I Zone B (n= 358) 
L \ ~H Zone C (n=814) 
50 100 150 200 250 300 350 400 450 500 550 600 
Standard length (mm) 
Figure 10 
Length frequency of ladyfish, Elops saurus , plotted by sampling zones 
in the Indian River Lagoon. Banana River and Indian River basins 
are identified in Figure IB. Early- and mid-metamorphic larvae were 
excluded. Data from all years (1990-95) and gear types were plotted. 
n = number of fish sampled. 
reduce ladyfish growth rates. The timing of ingress into 
the Cuban estuaries by metamorphosing larvae was not 
reported by Carles (1967); therefore it is not clear if over- 
wintering sizes are comparable (i.e. if they represent the 
same seasonal growth period). If ingress into the Cuban 
estuaries occurred later than spring (i.e. when ladyfish 
entered Florida estuaries), then this would shorten the 
length of the growing season and could explain Carles’ 
(1967) results. This preliminary attempt to link salinity 
to growth rate, although suggestive, requires verification 
of reduced growth rates in hypersaline conditions. Exper- 
imental studies to determine the optimal salinity for la- 
dyfish growth and survival will clarify whether ladyfish 
benefit by actively selecting low-salinity habitats. Such 
information would be the last step in demonstrating that 
ladyfish depend on estuaries and for showing the rela- 
tive value of positive estuaries (with low salinity areas) 
to negative estuaries (with hypersaline conditions) for la- 
dyfish populations. It would also be the next step for de- 
fining the essential fish habitat of ladyfish and for pre- 
dicting the effects of changes in estuarine salinity on this 
fishery species. 
Acknowledgments 
Sampling throughout Tampa Bay and the Indian River 
Lagoon was supported in part by funding from the Depart- 
ment of the Interior, U.S. Fish and Wildlife Service, Fed- 
eral Aid for Sport Fish Restoration, project F-43. Sampling 
was also funded in part by sales of Florida’s saltwater 
fishing licenses and special State of Florida appropria- 
tions to the Florida Department of Environmental Protec- 
tion (FDEP). Sampling in the Little Manatee River was 
made available through grants CM-254 and CM-280 from 
the Department of Environmental Regulation, Office of 
Coastal Management, with funds made available through 
the National Oceanic and Atmospheric Administration 
under the Coastal Zone Management Act of 1972, as 
amended. Sampling of Gulf of Mexico beaches was funded 
