Selective Predation by Procladius in an Arctic Alaskan Lake

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Author: Hershey, Anne E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1986
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Arctic
• Online Access: http://dx.doi.org/10.1139/f86-312; http://www.nrcresearchpress.com/doi/pdf/10.1139/f86-312

In arctic Alaskan Toolik Lake, the predatory larval chironomid Procladius spp. (Diptera) feeds on a variety of benthic organisms including algae, other chironomids, and microcrustaceans. Laboratory experiments with two similar-sized chironomid prey, instar I Chironomus and instar II Paratanytarsus, showed that Procladius was a more effective predator on Chironomus. The two prey used different foraging behaviors; Chironomus grazed an area around its tube but Paratanytarsus remained inside its tube. In a field experiment, in which Procladius density was manipulated, a decrease in prey density occurred in the chironomid group Orthocladiinae, which could be attributed to Procladius predation. Gut analyses of Procladius showed that a higher proportion of Orthocladiinae was eaten than could be predicted from their abundance. Orthocladiinae, which typically graze around tubes, may have been more susceptible to Procladius because of behavioral characteristics.