Metabolic Rates of Ephemerid Nymphs From Swiftly Flowing and From Still Waters

Abstract

1. The oxygen consumptions of the small ephemerid nymphs Ephemerella ignita and Coenis sp. are (anaesthetised at 10° C.) 950 and 290 c.mm./gm./hour. Their habitats are respectively a stream and a pond. 2. The oxygen consumptions of the large ephemerid nymphs Ecdyonurus venosus, Ephemera danica and E. vulgata are (anaesthetised at 10° C.) 604, 370 and 278 c.mm./gm./hour. They live, respectively, under stones in a swift stream, burrowing in sand in a stream, and burrowing in mud in a pond. 3. Ecdyonurus venosus is less resistant to oxygen deficiency than Ephemera danica and E. vulgata; and Baetis rhodani (swift stream) is less resistant than Chloeon dipterum (pond).