Optimum food particle size in relation to body size of common carp, Cyprinus carpio L., fry.

An investigation was conducted under laboratory conditions to determine the optimum food particle size of an inert diet for common carp fry ranging in size from 15 to 466 mg body weight and 13 to 31 mm total length (TL). Speed of consumption of a standard quantity of food was used as a measurement of feeding preference/efficiency for different particle size ranges. It was observed that for carp of this size range preferred food particle size increases with fish size. On the basis of ingestion time and feeding behaviour, food particle sizes in the ranges 125–300 μm. 300–500 μm, 300–790 μm and 500–1000 μm diameter were found to be most appropriate for carp fry weighing 15–23mg(TL 13–18), 46–97mg(TL 17–22), 105–209 mg(TL 20–25) and 210–466 mg (TL 24–31) respectively. This study also demonstrated that for carp fry of these size ranges the mean preferred food particle sizes are about 0.2–0.4 that of mouth size. Based on this relationship, general recommendations are made on the optimum food particle sizes for different size classes of carp fry reared under hatchery and nursery conditions. [ABSTRACT FROM AUTHOR]