Comparison of three live foods and two dry diets for intensive culture of grass carp and bighead carp larvae.
In trial 1, grass carp larvae (Ctenopharyngodon idella) stocked at 13 fish/litre were fed on Artemia, rotifers (Brachionus rubens), nematodes (Panagrellus sp.) or 1 of 2 commercial dry diets. In trials 2 and 3 bighead carp larvae (Hypophthalmichthys nobilis) stocked at 57 and 28 fish/litre, respectively, were fed on the same diets. Grass carp and bighead carp larvae fed on rotifers were consistently longer and heavier than fish fed on the other feeds. The final length of grass carp fed on nematodes was the lowest of the live feeds tested, however, the length of bighead carp fed on nematodes was similar to those fed on Artemia. Growth of grass carp fed the commercial dry diets was less than those fed the live feeds. Bighead carp grew well on the commercial diets, but results were somewhat inconsistent. Construction of a simple, inexpensive airlift sponge filter is described. This filter provided adequate water quality, resulting in excellent survival at densities as high as 57 individuals/litre with no addition of freshwater. The airlift sponge filter has great potential for intensive larval rearing.