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Title: Etiology of Early Lifestage Diseases, Project 84-44, 1985 Final Report.

Technical Report ·
DOI:https://doi.org/10.2172/7166620· OSTI ID:7166620

Each year hatcheries experience loss of eggs, fry and fingerlings due to a group of poorly defined diseases called White Spot and Coagulated Yolk. Samples of maternal blood and ovarian fluid (coelomic fluid), as well as unfertilized eggs, were collected at spawning and subsequently tested for the presence of bacteria. Our tests reveal that there is a wide range in mortality rates experienced by the progeny of different brood salmon. Microbiologic tests revealed that these eggs contained a variety of both Gram positive and Gram negative bacteria within their yolk and that the fluids from the females who produced these lots were contaminated with a variety of bacteria. In contrast the eggs and maternal fluids from the six egg lots which experienced the lowest mortalities did not contain high numbers of Gram positive bacteria and contributed only 5% of the total mortalities observed within the 30 egg lots tested. From the 60 egg lots tested over two brood years we have isolated 18 different bacterial genera containing 32 different species from within the yolk surface sterilized, unfertilized eggs. Our tests suggest that Aeromonas hydrophila, Pseudomonas (3 species) Staphylococcus aureus, Vibrio sp., Corynebacterium hoffmanii, Listeria sp. and Bacillus sp. when detected within the yolk of eggs sampled from egg lots prior to fertilization will be associated with higher than normal mortality rates when the remainder of the egg lots containing these bacteria are incubated and reared. 36 refs., 16 figs.

Research Organization:
Oregon Health Science University (OHSU)
Sponsoring Organization:
United States. Bonneville Power Administration.
DOE Contract Number:
1984BP18186
OSTI ID:
7166620
Report Number(s):
DOE/BP-18186-1; R&D Project: 1984-044-00; ON: DE87002985
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English