|MATTHEWS, MICHAEL - Florida Bass Conservation Center|
Submitted to: American Fisheries Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/20/2009
Publication Date: 6/8/2009
Citation: Bebak, J.A., Matthews, M., Shoemaker, C.A. 2009. Survival of vaccinated,feed-trained largemouth bass fry (Micropterus Salmoides Floridanus) during natural exposure to Flavobacterium columnare. In: Abstracts of the American Fishery Society (Fish Health Section). p. 28.
Technical Abstract: Largemouth bass (Micropterus salmoides floridanus; Centrarchidae) are often reared in government hatchery programs, then stocked to supplement wild fish populations. After the eggs obtained from broodstock are hatched, fry are stocked into ponds to feed on zooplankton and other small invertebrates. After this period eating live food the fry are more likely to accept commercial feed, so they are harvested from the ponds, stocked into tanks for “feed training”, and provided with manufactured feed until they are the size needed for stocking into lakes and ponds. Fry may be exposed to Flavobacterium columnare while they are in the pond and/or after they are moved indoors. Consequently, outbreaks of columnaris disease are likely to occur during and after this stressful feed training period. The objective of this study was to conduct a field trial testing the efficacy of AQUAVAC-COL™ (Intervet/Schering Plough Animal Health ) to enhance the survival of vaccinated (at 7 to 9 days post hatch) feed-trained largemouth bass fry naturally exposed to F. columnare. Vaccinated, feed-trained largemouth bass fry were cohabited with calcein marked sham-vaccinated fish. All fish were exposed, under natural conditions, to the bacterium. During every time interval, the probability that a vaccinated fish would survive past time, t, was greater than for sham-vaccinated fish and survivor functions were significantly different (p-value<0.001). Overall, vaccinated fish had a 43% lower risk of death during the field trial. Mean incidence was greater for the sham vaccinated as compared to the vaccinated fish. Vaccination with AQUAVAC-COL™ significantly reduced the risk of death from columnaris disease in feed-trained largemouth bass fry.