Bacteriological Studies of Fresh-Water Fish: I. Isolation of Aerobic Bacteria From Several Species of Ontario Fish

A total of 350 fish were taken from Ontario waters and examined for the presence of aerobic bacteria. Trout species accounted for 97.1% of the fish examined, and the remainder were "coarse" fish. A total of 1189 cultures of bacteria were isolated from hearts, livers, kidneys, spleens, muscles, and slime of the fish and from 11 of the waters they inhabited. Of this total, 221 cultures were lost through death, most of these organisms being too fastidious to survive the routine cultural methods employed. Of the remaining 968 cultures, 121 proved impossible to identify or group on the basis of common characteristics. The remaining bacteria were classified to the rank of genus as follows: 234 Pseudomonas, 140 Aeromonas, 111 Micrococcus, 96 Lactobacillus, 72 Escherichia, 57 Brevibacterium, 29 Para-colobactrum, 28 Aerobacter, 24 Proteus and other urea splitters, 18 Alcaligenes, 14 Bacillus, 11 Achromobacter, 7 Streptococcus, and 6 Flavobacterium.