Effects of system conditions on growth performance reproductive efficiency, sex hormones and seeds production of African catfish, Clarias gariepinus

Abstract Biofloc technology (BFT) is an aquaculture practices which rely on maintaining a minimum-water exchange throughout the culture period, presenting a promising solution to enable a more sustainable and eco-friendly approach to fish farming. The present study examined the effect of different rearing conditions (three treatment with three replicates):first treatment non-water exchange (NWE) system; without carbon source addition and without water exchange, second treatment, clear water (CW) system: without carbon source addition and with 50% water exchange weekly, and third treatment, biofloc technology (BFT) system; addition of molasses as carbon source daily without water exchange on the growth performance, blood biochemical parameters, sex hormones, reproduction efficiency and larval production of catfish brood-stock. Two phases of brood-stock were examined under the different rearing conditions including grow out phase and spawning phase. For the grow-out phase immature catfish males and females were distributed in concrete ponds (2 × 2 × 1 m 3 ). Each pond stocked with 15 fish (8 females and 7 males) at stocking rate 5 fish m −1 . Fish were fed at a rate of 2% of body weight/day, with a commercial diet containing 30% crude protein during the experimental period that continued for 120 days. For spawning phase brood fish were stocked in the same ponds and the same treatments at stocking rate of 4 brood-stock pond −1 (2 females and 2 males). The best water quality conditions, the highest growth parameters values, the better Absolute fecundity (AF), relative fecundity (RF), gonado somatic index (GSI), and egg diameters were recorded in BFT system compared to NWE and CW systems. The best blood biochemical parameters (cortisol, glucose, cholesterol, creatinine and urea) were recorded in BFT system. The superior larvae parameters were recorded in BFT system compared to NWE and CW systems. In conclusion biofloc technology is an appropriate condition for rearing African catfish where it has a positive effect on growth and reproductive performance of the brood fish.