Aquacultural Potential of Silver Catfish Chrysichthys nigrodigitatus (Lacepede, 1803) Bred in Fresh and Brakish Water in Three Rearing Systems: Enclosures, Cement Tanks and Earth Ponds

摘要

The effect of three rearing systems and two types of area, lagoon and fresh water, on growth and mortality rates of Chrysichthys nigrodigitatus was evaluated until 300 days in C?te d’Ivoire. Fish of average weight 21.09 g were stocked at a 10 fish/m3 density and fed a 35% protein pellet feed. Temperature, oxygen, pH, salinity and conductivity, were monitored. In lagoon, comparing survival rate, final mean weight and length, daily weight gain, specific growth rate and condition factor in the three rearing systems, respectively 70%; 395.29 g; 349 mm; 0.76 g/d, 2.260%/d ; 2.619 in cement tank, 68%; 392.40 g; 346 mm; 0.75 g/d 2.174%/d; 2.515 in enclosure and 70%; 395.53 g; 349 mm; 0,758 g/d. 2.238%/d; 2.520 in pond were noticed. In fresh water, values of these parameters are respectively 68%; 390.31 g; 344.8 mm; 0.746 g/d; 2.238%/d and 2.52. Growth parameters aren’t significantly different. This observation is not only between the three rearing systems but also in the two type of water. These similarities observed are link to the fact that firstly the three rearing systems seem to mimic nature. Secondly fish are in good condition because they take advantage of the natural resources in addition to artificial food.