The present study concerns bacterial transit in the digestive tract of rainbow trout at 13 degree C and compares fecal excretion of 4 tracers in the alimentary bolus, an inert bacterial tracer: spores of Bacillus stearothermophilus , a bacterial marker capable of multiplying in the digestive organs: Citrobacter freundii ; a tracer of the liquid phase: polyethylene glycol (PEG), a tracer of the solid phase: Cr sub(2)O sub(3). Two peaks of fecal excretion of bacterial bodies are indicated in the results, the first one taking place within the first 4 h following ingestion of the traced meal, the second peak, a hundred times more important, occurring 10 h after the meal. This two-phase mode of excretion corroborates the observations previously made. The... |