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Weaning success of pond‐cultured pikeperch and wild‐caught perch (mean length 51 and 48 mm respectively) was evaluated using different weaning techniques and different formulated feeds. Juveniles that were fed formulated feed grew as well as or better than juveniles that were weaned successively using zooplankton or yolk. Four different formulated feeds (agglomerated marine larvae feed, marine larvae feed, trout feed and a semi‐moist feed) were evaluated regarding specific growth rate (SGR), condition factor and a subjective stomach fullness estimate. The agglomerated marine larvae feed gave significantly better weaning performance than the other feeds regarding all parameters (SGR = 7.3% day−1 and 3.4% day−1 for pikeperch and perch respectively).

Young‐of‐the‐year perch Perca fluviatilis were presented with a novel food type, dry feed, in the presence or absence of demonstrators, who were experienced to the feed. Most inexperienced fish lost mass in the beginning of the study, but untrained fish in the presence of demonstrators already had positive average growth during the first time period. There was a positive correlation between boldness and body mass change. Both social environment and individual characteristics thus seem to affect learning in perch.

The coefficient of variation of individual food intake was large in small groups of young-ofthe-year perch Perca fluviatilis (45-60 mm L T ) and smaller when fish that were given the same feeding rank were placed together. No aggressive interactions were detected during feeding. 2002 The Fisheries Society of the British Isles

Juvenile (0+ year) perch Perca fluviatilis, held in tanks (1 m3) for 8 months under constant temperature (17° C) and light (12L : 12D) conditions, were weighed monthly. Individually marked fish from the tanks were placed in aquaria in groups of four and tested for feeding success, assessed as individual share of a group meal in three identical short‐term aquarium experiments separated in time (January, May and June). The groups consisted of the same individuals in each of the three experiments. In tanks, growth (thermal growth coefficient, GT) was used as a measurement of feeding success. Individual GT in tanks was consistent over time, and individual share of a group meal in aquaria was consistent between consecutive months. There was no connection between individual feeding success in aquaria and GT in tanks in May and June, and in January the factors were negatively correlated. The condition factor at the start of aquarium experiments and feeding success in aquaria were negatively correlated in June and tended to be so also in May. Boldness in aquaria was negatively correlated with growth in tanks. Thus, individuals that were successful in one environment seemed to be less successful in the other. There was a seasonal change in GT, with an increase from March to April and from April to June despite constant day length and temperature.

The coefficient of variation of individual food intake was large in small groups of young-ofthe-year perch Perca fluviatilis (45-60 mm L T ) and smaller when fish that were given the same feeding rank were placed together. No aggressive interactions were detected during feeding. 2002 The Fisheries Society of the British Isles