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The Ecology of Baetis muticus and Baetis rhodani (Insecta, Ephemeroptera), with Special Emphasis on Acid Water Backgrounds
Author(s) -
Willoughby L. G.
Publication year - 1988
Publication title -
internationale revue der gesamten hydrobiologie und hydrographie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 52
eISSN - 1522-2632
pISSN - 0020-9309
DOI - 10.1002/iroh.19880730303
Subject(s) - biology , ecology , streams , zoology , computer network , computer science
The two mayflies (Insecta, Ephemeroptera) Baetis muticus and Baetis rhodani are absent from the acid water (pH 4.8–5.2) streams of the Upper Duddon drainage basin. Field observations and laboratory experiments were used in an attempt to explain this absence. Baetis muticus could not tolerate acid water; in addition it was deduced that available foods in the Upper Duddon streams would not sustain it there, even if the water could be tolerated. Baetis muticus feeds by browsing on decaying, allochthonous leaves, implying an input of micro‐organisms, especially fungi, to the diet. Well‐decayed, allochthonous leaves do not occur in the acid water, Upper Duddon streams. Baetis rhodani proved to be acid water tolerant, but only if the background waters had high ionic loadings. Since Upper Duddon waters have only low ionic loadings, Baetis rhodani is apparently excluded from them on this account. The evidence was that if the Upper Duddon waters were chemically suitable, then Baetis rhodani could survive in them, because a suitable food, the alga Hormidium subtile is present.