622 Marine Microbiology 



utilized citrate as sole carbon source. Only a slightly greater over- 

 all proteolytic-activity can be ascribed to those species from verte- 

 brate animals. Flavohacterium sp. isolated from invertebrate 

 animals showed a pronounced ability to liquefy gelatin. Thus, 

 w^ith the exception of a few characteristics in Acliromobacter and 

 Flavohacterium, the physiological properties of each of the ma- 

 jor groups con^esponded well with the general pictine for the 

 total flora in vertebrates and invertebrates. Within the limitations 

 of the noiTnal range of properties of the different genera, species 

 having similar physiological characteristics tend to predominate 

 in the particular environment provided by the vertebrate or in- 

 vertebrate body. 



Unfortunately there is insufficient information presently 

 available on the normal chemical, or even physical, conditions of 

 the exposed surfaces of marine animal bodies to correlate the 

 observations on bacterial physiology with the actual nutritional 

 composition of the microenvironment. In view of the reasonably 

 clear cut picture which emerged from the results of this study, it 

 would seem that studies in this general area might be rewarding. 



SUMMARY 



An analysis was made of data obtained from a study of 743 

 bacterial cultures associated with nineteen species of marine ver- 

 tebrates and circa fourteen species of invertebrates captured in 

 several areas of Puget Sound and off the Washington Coast, in 

 the northern Pacific Ocean, and in several areas near Eniwetok 

 Atoll and in Rongelap Lagoon in the southern Pacific Ocean. 

 Gram-negative, asporogenous, rod-like bacteria predominated in 

 all populations of bacteria isolated from tlie marine animals 

 sampled. There was little evidence of any major taxonomic differ- 

 ences between bacterial populations of vertebrates and inverte- 

 brates or among populations derived from different geographical 

 areas. Pseudomonas and Achromohacter sp. predominated in 

 all samples studied, but minor differences were observed in the 

 proportions of these and other bacterial groups present. Popula- 

 tions of bacteria associated with sessile invertebrates generally 

 included greater numbers of Micrococcus and Flavohacterium 

 sp. than populations associated with vertebrates taken in the 



