Abstract
Feeding rates, time of feeding, and prey choice of brook trout (Salvelinus fontinalis) were studied in Cement Creek, Colorado, in 1975–77. On each of five dates from early June to late September, I collected trout at intervals over a 24-h period, along with samples of invertebrate drift and benthos. Although substantial individual variation was observed in time of feeding and prey choice, feeding during the day appeared to predominate. The period of peak feeding shifted from 18:00–22:00 in June–July to earlier hours in August–September. The average number of prey per predator declined over the season and trout relied more heavily on terrestrial forms as aquatic taxa became more rare. The weight of food eaten per day was ~3–4 × the average amount observed per stomach.The numerical abundance of prey in the diet was significantly correlated with abundance of prey in the drift. Except for a few trout which ingested large, rare prey, this was also true for prey composition by biomass. Large taxa tended to be consistently overrepresented in trout diet and small taxa underrepresented. Several prey species shifted from underrepresentation in trout diets to overrepresentation as they grew in size. Abundance and size of prey, along with individual specialization by trout presumably as a result of experience, are suggested as primary determinants of trout diet.Key words: brook trout, Salvelinus fontinalis; stream, predator-prey, aquatic insects
Publisher
Canadian Science Publishing
Subject
Aquatic Science,Ecology, Evolution, Behavior and Systematics
Cited by
198 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献