Field experiment reveals no relation between substrate composition and Chironomus abundance

Pages 19-27 : illustrations ; 27 cm

Bibliografia na stronach 26-27

Bibliographical references (pages 26-27)

In the field experiment no relation between organic matter content (0-83%) in substrates provided and Chironomus plumosus (L.) abundance was found. Numbers of larvae and their age structure were usually similar on the mineral substrate and various bottom sediments but sometimes differed up to 2-3 times (at the same site and date of sampling); there was however no correlation with the quality of substrate. This indicates that the feeding of Chironomus plumosus did not depend on the bottom deposit the larvae lived in, but mostly on sedimenting tripton, which formed a thin layer on the top of substrates provided. Also mutual relations of individuals and the period of exposure of the sediment (from 3 weeks to few months) did not matter. Very high abundance of Ch. plumosus (up to 90 thousands ind. m-2) found already after 3 weeks exposition in the sediment initially without that species indicates a very high growth potential of the Chironomus population at the study site.

Strony 19-27 : ilustracje ; 27 cm