Abstract
Freshly captured chaetognath Sagitta samples were grouped into apparently healthy and abnormal specimens and the viable heterotrophic bacterial population of both groups were ex-amined. The bacterial population ranged from 1.3×102 to 1.0×104 per animal, and was one order higher in opaque specimens regardless of whether they were still moving or moribund at the time of capture. Although Pseudomonas-Alteromonas was the predominant bacteria in both groups, Vibrio comprised 36.3%, of the bacterial population in the abnormal Sagitta. By the method of numerical taxonomy the total 143 strains were grouped into 14 main phena, of which 4 were exclusively composed of strains from healthy Sagitta and 1 from abnormal Sagitta. The rest of the strains were unevenly distributed into 9 phena, 4 of which were mostly comprised of strains from abnormal Sagitta and 1 of which mostly included strains from healthy Sagitta. In general, the isolates of abnormal Sagitta grew under a wide range of physiological conditions and showed greater hydrolytic activities of organic compounds.
