اثر طول دوره روشنايي - تاريكي بر بار باكتريايي روده ماهي سفيد (Rutilus frisi kutum) در مرحله نوزادي

The effect of photoperiod on gut bacterial load in (Rutilus frisii kutum) in juvenile stage

In this study, the effect of photoperiod on the gut bacterial load in Rutilus frisii kutum and also the simultaneous relation between regulated light levels and LAB bacteria load on the growth and mortality were evaluated. Fish were received six photoperiod regimes: natural photoperiod, 24L:0D, 16L:8D, 12L:12D, 8L:16D and 0L:24D. There was no significant relation between light hours and LAB (P = 0.956) and total viable counts (P = 0.079) in following treatments 2-6. There was a high determination coefficient (R2 = 0.72) among light hours and intestinal LAB counts with mortality, but no significant difference was observed (P = 0.272). Keywords: Photoperiod, Rutilus frisii kutum, Gut bacterial load, LAB.