Occurrence of Vibrio and other bacteria on the sea nettle, Chrysaora quinquecirrha

Sixty-two specimens of the sea nettle, Chrysaora quinquecirrha, were caught in the lower Chesapeake Bay, homogenized, and samples plated on a yeast extract-Bay water agar. Bacterial colonies were selected randomly, purified, and tested for 180 characteristics. Computer analysis permitted clustering of the 208 isolates into 15 groups (comprised of 133 strains) plus 75 nongrouped strains which failed to associate with any group at the 70% similarity level. The majority of the isolates (68.8%) were Vibrio species. These included 110 of the grouped strains (forming 12 of the 15 groups) and 33 of the nongrouped strains. The remainder of the isolates were distributed as follows:Pseudomonas (11.6%), Bacillus (8.2%), Flavobacterium (2.4%), Acinetobacter (2.4%), Moraxella (1.9%), Cytophaga (1.9%), Gram-positive cocci (1.4%), and miscellaneous (1.4%). All the Bacillus were isolated from a group of moribund nettles and reflect an abnormal condition. Vibrio species predominated in the five "catches" of healthy nettles, but were distinctly different for each catch.