Landlocked Fall Chinook Salmon Kidney Bacteria in Relation to Egg Survival

Abstract

AbstractA survey of kidney bacteria from female landlocked fall Chinook Salmon Oncorhynchus tshawytscha broodstock from Lake Oahe, South Dakota, was conducted to investigate possible links to subsequent egg survival. Bacteria were isolated from 22 spent females. The kidneys of two females contained no bacteria, and no eggs survived from the spawn of these two fish. All kidneys sampled appeared normal with no gross abnormalities. Twelve bacteria genera were isolated and identified to the genus level: Acinetobacter, Aeromonas, Brevundimonas, Chryseobacterium, Flavobacterium, Acidovorax, Arthrobacter, Deinococcus, Enterococcus, Leucobacter, Micrococcus, and Oerskovia. Screening for Renibacterium salmoninarum was not conducted. Colony forming units (CFU) per gram ranged from 0 to 10,542. There were no significant correlations between egg survival and CFU from samples incubated on agar containing either R2A or Coomassie Brilliant Blue. In addition, no relationship was observed between any of the bacterial species isolated and egg survival to the eyed stage. Bacteria present in the kidneys of this specific population of Chinook Salmon do not appear to have any effect on female condition or subsequent egg survival, although several potentially pathogenic bacteria genera were isolated.