著者

吉水 守 木村 喬久 坂井 稔

出版者

日本水産學會

雑誌

日本水産学会誌 (ISSN:00215392)

巻号頁・発行日

vol.42, no.8, pp.863-873, 1976

被引用文献数

2 9

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A total of 92 masu salmon (Oncorhynchus masou) which had developed silvering were divided into 4 groups. Three of these groups were transplanted from fresh water. The feeding conditions varied with the group. Viable counts were determined in the intestinal contents or slime of these salmon, in their ambient waters and in their diets. Over 1500 strains were isolated from the above samples. The composition of the microflora was determined according to the scheme of Shewan <i>et al</i>. (1960).<br> The results are summarized as follows:<br> 1) Microbial viable counts in the intestinal contents or slime of the fish which were transplanted under normal feeding conditions were nearly constant while those which were transplanted without being fed decreased rapidly. This decreasing tendency was found in both fresh and sea water reared non-feeding fish.<br> 2) The predominant genus in the intestinal microflora of the fresh water fish was <i>Aeromonas</i>, while in sea water fish it was <i>Vibrio</i>. Upon transplanting the fish from fresh water into sea water fish it was Vibrio. Upon transplanting the fish from fresh water into sea water, <i>Aeromonas</i> of the terrestrial type was gradually replaced by <i>Pseudomonas</i> as the proportion of sea water in the rearing water increased. This was followed by further replacement by <i>Vibrio</i> of the halophilic type which became predominant in the intestinal microflora.