Feeding requirements of sea bream (Sparus aurata) larvae under intensive rearing conditions - Development of a fuzzy logic controller for feeding

Applied methods for larval rearing suffer from the difficulty of accurately predicting larvae quantitative feeding requirements for optimum growth. Ev en when known, requirements change according to the behavior of each popula tion reared. Computer based feeding systems require tools for adapting the delivered amounts of food to the needs of the reared population. In this wo rk the daily feeding requirements of sea bream (Sparus aurata) larvae were estimated, and based on these estimations a fuzzy logic controller (FLC) fo r feeding was designed and developed. Sea bream larvae were reared, in trip licate, under intensive conditions in a pilot scale rearing system for 20 d ays with the pseudo-green water method. Larvae reached 6.7 +/- 0.6 mm (mean value and S.D.) at the end of the experimental period while the mean survi val of the populations was 48.0 +/- 12.6%. Consumption was 0.017 +/- 0.009 mg of carbon per individual at first feeding and increased to 0.198 +/- 0.0 32 mg at day 20 post-hatching. The findings were used for the development o f a FLC for feeding that adapts the amount of food delivered to the larvae according to changes in the reared population. The FLC utilizes five lingui stic variables describing the state of the population and a rule base compo sed of 316 rules. The developed FLC allows the use of computer based feedin g systems during rearing of early larval stages. (C) 2000 Elsevier Science a.V. All rights reserved.