Showing papers by "Richard W. Merritt published in 1993"

Bacterial enrichment in the surface microlayer of an Anopheles quadrimaculatus (diptera: culicidae) larval habitat.

Abstract: Sampling of the surface microlayer of water in a marsh habitat of Anopheles quadrimaculatus Say in Michigan revealed it to be enriched with bacteria compared with subsurface water samples. Concentrations of total numbers of bacteria ranged from 18.8 x 10(6)/ml to 65.4 x 10(6)/ml (mean, 35.9 x 10(6)/ml; n = 13) in surface microlayer samples, and from 3.8 x 10(6)/ml to 14.3 x 10(6)/ml, (mean, 7.8 x 10(6)/ml; n = 13) in subsurface samples. Specifically, the surface microlayer had higher concentrations of three morphotypes of bacteria (cocci, rods, and rods attached to detritus particles). Given that bacteria are an important food of mosquito larvae, we suggest that the interfacial feeding behavior of An. quadrimaculatus larvae allows them to exploit the surface microlayer, a food-rich zone.

Feeding variability among individual aquatic predators in experimental channels

Abstract: Experiments were conducted in experimental channels to study feeding variability through time and between conspecific individuals of four species of lotic predators. Large and small Rhyacophila dor...