128 



NORSE 



exasperatus dominate. Callinectes ornatus, C. marginatus, and C. 

 exasperatus dominate biotopes having virtually undiluted seaw^ater. 

 Similar patterns exist in regions having long-lasting hyposaline 

 environments (e.g., Miami; Cienaga Grande de Santa Marta, 

 Colombia). In areas lacking permanent hyposaline vi^aters (e.g., the 

 keys; areas near Santa Marta, Colombia; and Curagao), however, the 

 portunid species composition changes with the degree of exchange 

 with the sea. Thus the back bays most tenuously connected with the 

 sea have only the Callinectes that occur below 10%o in wetter 

 regions. 



TABLE 3 



SPECIES COMPOSITION OF JAMAICAN PORTUNIDS 

 IN FOUR SALINITY CATEGORIES 



