ZoBell — 188 — Marine Microbiology 



terial fermentation of glycogen, followed by a period of abundant gas 

 production. Proteolytic bacteria subsequently complete the disintegra- 

 tion of the oyster tissue. 



Bacteriology of marine fish: — Wood (1940) deduced, from the ab- 

 sence of coliform bacteria in fish, that the likelihood of marine fish con- 

 veying typhoid, dysentery, or other enteric infections to man is very re- 

 mote except through careless handling. This deduction is in complete 

 harmony with the findings of Griffiths and Fuller (1936) and Gibbons 

 (1934Z)). From his extensive survey, Gibbons (19346) concluded that 

 representatives of the genera Escherichia and Aerohacter seldom occur in 

 fish taken from waters at considerable distances offshore. "The fecal 

 forms are particularly rare, except in fish taken near shore or in contam- 

 inated waters." 



Only II of the 412 cultures isolated from the intestines of salmon by 

 Fellers (1926) proved to be E. coli. The kinds of bacteria which he 

 found in fish slime were essentially the same as those in decomposing 

 salmon flesh. Sarcina lutea, Micrococcus varians, and an acid-forming 

 Streptococcus predominated. Fresh salmon slime contained 370 bacteria 

 per ml. After two hours at 16.7° C. the count increased to 1,950 bacteria 

 per ml., and after 24 hours there were 3,900,000 bacteria per ml. of slime. 

 Fellers concluded, as did Hunter (1922), that the organisms respon- 

 sible for decomposition of marine fish are those whose normal habitat is 

 sea water or fish slime. Hunter isolated 316 cultures, including 85 dif- 

 ferent species, from sea water, decomposing salmon, and salmon canneries. 

 All of them were asporogenous rods except 4 streptococci, 3 sporogenous 

 rods, I actinomyces, and i pink yeast. Four coliform bacteria were 

 identified. 



Species of Bacillus predominated among the organisms isolated from 

 mackerel, haddock, halibut, sole, smelt, and butter-fish studied by Har- 

 rison et at. (1926). The tissues of fresh fish were found to be sterile. The 

 gills act as an important source of infection. Puncturing or otherwise 

 damaging fish introduces bacteria from the slime and intestinal contents. 

 Fish decompose more rapidly when the alimentary canal is full of food 

 than when empty. If fish are beheaded, eviscerated, and frozen soon after 

 catching, they may be kept safely for several months. Spoiled fish may 

 contain up to 400,000,000 bacteria per gram. 



Bacteria isolated from the surface slime of haddock were identified by 

 Reed and Spence (1929) as follows: 24 per cent Bacillus, 23 per cent 

 Achromobacter, 22 per cent Pseudomonas, 18 per cent Proteus, 8 per cent 

 Flavobacterium, and 4 per cent Micrococcus. In the intestinal contents of 

 haddock 70 per cent of the bacteria were Proteus species. Members of the 

 coli-aero genes group were found in the intestinal contents of haddock only 

 occasionally and never in the integumental slime. Achromobacter-\ike 

 species predominated in the slime of haddock examined by Stewart ( i 93 2) , 

 followed in abundance by Micrococcus, Flavobacterium, and Pseudomo7ias. 

 Escherichia coli was not found, and very few species of Aerobacter were iso- 

 lated from haddock. 



From the slime and feces of 43 marine fish, representing 11 different 

 species, Gibbons (1934a) isolated 80 pure cultures of bacteria, including 

 31 Achromobacter , 18 Flavobacterium, 15 Micrococcus, 5 Pseudomonas, 5 Ba- 

 cillus, 2 Proteus, I Fberthella, and i Serratia. Taken collectively, the bacte- 

 rial flora of slime was found to be similar to that of fish feces. Most investi- 



