Abstract
AbstractFor evaluating hydraulic stress reduction strategies of caddisfly larvae, our study has three goals. First, creating a database on Reynolds numbers (Re) and drag coefficients valid for Limnephilidae larvae with cylindrical mineral cases. Second, evaluating the effects of submerged weight and biometry in cases with comparable length/width ratios. And third, collecting field data in an alpine environment for gaining insights into the hydraulic niches occupied by thirteen Drusinae species. Biometric data were subsequently combined with published Reynolds numbers and mean flow velocity data measured immediately upstream of Limnephilidae larvae at the moment of dislodgement. This provides drag coefficients for the range of Reynolds numbers obtained in the field. Data reveal that heavy cases strongly benefit from compensating drag by submerged weight, thereby enabling species to utilize high velocity spots, an important benefit for filtering species.
Publisher
Springer Science and Business Media LLC
Reference26 articles.
1. Bohle, H. W., 1987. Drift-fangende Köcherfliegen-Larven unter den Drusinae (Trichoptera: Limnephilidae). Entomologica Generalis 12: 119–132.
2. Dingman, S. L., 1984. Fluvial Hydrology. Freeman and Company, New York:
3. Gordon, N. D., T. A. McMahon & B. L. Finlayson, 1992. Stream Hydrology, Wiley, Chichester:
4. Gallepp, G. W., 1977. Response of caddisfly larvae (Brachycentrus spp.) to temperature, food availability and current velocity. The American Midland Naturalist 98: 59–84.
5. Hoerner, S. F., 1965. Fluid-Dynamic Drag: Practical Information on Aerodynamic Drag and Hydrodynamic Resistance, Hoerner Fluid Dynamics, Bakersfield: