Survival, Condition, and Pathogen Load of Channel Catfish Fingerlings Following Transport
Edward N. Sismour, M. David Crosby, Scott H. Newton, and Michael L. Fine
Abstract.—U.S. Game and Fish agencies and farm-pond owners throughout the United States use commercially produced channel catfish Ictalurus punctatus fingerlings transported from the southern United States for supplemental stocking. We conducted six trials to examine whether pathogen load, body condition, and select environmental factors influence fingerling survival following transport and cage stocking. Fingerlings were sampled prior to stocking and weekly for the following 3 weeks. Weights and lengths were measured, and a relative condition index was used to quantify body condition. Skin scrapings and gill clippings were examined microscopically for pathogens, and posterior kidney was assayed for Aeromonas hydrophila. Mortality was either less than 10% (four trials) or catastrophic (two trials). A Columnaris disease epizootic was associated with ~50% mortality in one trial, and a red sore disease epizootic was associated with ~80% mortality in another. Body condition or other pathogens, present initially or acquired in study ponds, were not associated with high mortality. The first week appears to be critical for the survival of channel catfish fingerlings following transport.