FORAGING MOVEMENTS IN RELATION TO MORPHOLOGY, WATER-COLUMN USE, AND DIET FOR RECENTLY EMERGED BROOK TROUT (SALVELINUS-FONTINALIS) IN STILL-WATER POOLS

Recently emerged brook trout (Salvelinus fontinalis) foraging is still -water pools varied considerably in the proportion of time they spent moving, speed while moving, and distance travelled during pursuit of p rey. Trout that exhibited a high proportion of time spent moving, fast speeds while moving, and long pursuit distances directed more foragin g attempts toward the upper portion of the water column, ate more inse ct prey and fewer crustaceans, and made more foraging attempts per min ute than trout that exhibited a low proportion of time spent moving, s low speeds while moving, and short pursuit distances. The variation in movement was related less strongly to spatial heterogeneity in the lo cations (pool sizes, water depths) where individuals were observed. It was not significantly related to measures of temporal variation in th e environment (date, time-of-day, water temperature), body size and sh ape, or hunger (the amount of food in the stomach). In these clear, sh allow pools, differences in the spatial distribution and behaviour of prey types apparently facilitate divergent foraging behaviour and diet among the trout. Our findings are valuable for understanding the deve lopment and maintenance of the individual specializations in water-col umn use and diet reported previously for several salmonids.