Bacteria associated with hemolymph in the crab Callinectes bocourti in Puerto Rico

Crabs of the genus Callinectes are commonly found in coastal, estuarine and lagoon waters of the Caribbean, the Gulf of Mexico, and the Atlantic and Pacific coasts of Central America (Williams, 1974; Norse, 1978). One of the most abundant and commercially important species is the blue crab C. sapidus. At least six species of Callinectes are naturally found in Puerto Rico (Buchanan and Stoner, 1988; Stoner and Buchanan, 1990). Bacteria associated with Callinectes spp. hemolymph is of public health significance due to the presence of potential human pathogens (Sizemore et al., 1975). Hemolymph from sea hares and sipunculid worms has been shown to be sterile (Pauley et al., 1971; Bang and Krassner, 1958). However, bacteria in hemolymph of invertebrate blood systems have been isolated from lobsters (Stewart et al., 1966), dungeness crabs (Faghri et al., 1984) and blue crabs (Callinectes sapidus) (Sizemore et al., 1975; Davis and Sizemore, 1982). Naturally occurring bacterial flora isolated from blue crab hemolymph include several potential human pathogens such as Aeromonas sp., Pseudomonas sp., Flavobacterium sp., Bacillus sp., and Vibrio sp.; the latter being the predominant bacterial genus (Sizemore et al., 1975; Colwell et al., 1975). Bacterial species V. cholerae, V. vulnificus and V. parahaemolyticus have been isolated from blue crab hemolymph (Davis and Sizemore, 1982). Densities in excess of 10(5) bacteria ml(-1) have been reported in the hemolymph of blue crabs in Galveston Bay, Texas. Higher water temperatures apparently enhance bacterial proliferation in the hemolymph of live crabs (Davis and Sizemore, 1982). Literature describing the microflora of blue crabs is limited and, to our knowledge, no microbiological study has been performed in the hemolymph of Callinectes spp. living in the tropics. This study attempts to quantify total bacterial densities and identify species of bacteria in the hemolymph of C. bocourti in a high nutrient eutrophic system in Puerto Rico