Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 30 April 1982:
Vol. 216. no. 4545, pp. 533 - 534
DOI: 10.1126/science.216.4545.533
Prev | Table of Contents | Next

Articles

Current Speed and Filtration Rate Link Caddisfly Phylogeny and Distributional Patterns on a Stream Gradient

D. N. ALSTAD 1

1 Department of Biology, University of Utah, Salt Lake City 84112

Patterns of body size and net construction suggest that current speed and food-particle concentration (not size) influence the distribution of suspension-feeding caddisflies on a downstream gradient. Large ancestral taxa with high filtration rates occur in resource-poor upstream habitats; more derived members of the phylogeny enter successively in downstream reaches with slower current and greater concentrations of particulate food.

Submitted on December 28, 1981

To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)