The Husbandry and Nutrition of Carp Larvae and Fry

Abstract

In an investigation of the possibility of developing an artificial substitute for live food during first stage rearing of mirror carp (Cyprinus carpio) larvae, diet presentation and related husbandry techniques, as well as selected nutritional requirements of carp juveniles, were studied. Carp larvae held at a temperature of 24°C in continuous light showed optimal growth and food conversion during the first five days after commencement of feeding when given Artemia nauplii in amounts ranging from 200–250% of body weight per day, reducing to 100–120% of body weight per day during the following five days. It was found that carp larvae could be successfully reared on a dry, compounded commercial fry diet from a live body weight of approximately 15 mg, and that carp post-larvae of 15–100 mg body weight fed this diet showed optimal growth and food conversion for feeding rates of 15.0–17.5% of body weight per day. Carp fry of 100–500 mg body weight showed optimal growth and food conversion for feeding rates of 10–15% of body weight per day. These feed quantities were best administered in 12 equal amounts over 24 hours. It was also shown that presentation of green coloured diets to carp fry held on matching coloured backgrounds improved growth and food conversion. It was postulated that a dietary crude protein content of 45% was optimal for carp fry of 100–500 mg live body weight, and that inclusion of lipid at levels above 5% of the dry diet did not appear to offer any advantages in terms of growth. Manufacture of water-stable diets by the use of various binding agents and micro-encapsulation techniques did not substantially improve the performance of diets offered to carp larvae immediately after hatching, and it was concluded that further research will be required before it will be possible to eliminate the use of live food as a first food for carp larvae.