Abstract
Bacterial populations in gut contents and gills of seven marine crustacea were investigated qualitatively and quantitatively using nine different agar media. Total viable counts of the gut contents ranged from 105 to 109 cells g-1 and, of the gills, from 106 to 107 cells g-1. Three types of anaerobes, the Gram-positive coccus, Gram-positive rod and Gram-negative rod, were detected in 16.3%, 9.3% and 2.3%, respectively, of the crustacean samples examined. Although Pseudomonas and 6 of the 20 subgroups of the genus Vibrio were distributed widely among the crustacea, other bacterial components were also present in significant number in the selected crustacean species, individual specimens, or specimen tissues. Furthermore, cardinal growth temperatures of the bacterial isolates obtained in this study suggest the surrounding water temperature to be a major factor influencing apparent seasonal shifts in the gut microflora.
