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Circadian Changes in Feeding Activity and Diet of Hydropsyche saxonica (Trichoptera)
Author(s) -
Tajmrová Lenka,
Helešic Jan
Publication year - 2007
Publication title -
international review of hydrobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 52
eISSN - 1522-2632
pISSN - 1434-2944
DOI - 10.1002/iroh.200610994
Subject(s) - instar , detritus , biology , larva , foregut , zoology , botany , ecology , anatomy
Circadian changes in feeding activity and diet of instar IV and V larvae of Hydropsyche saxonica were studied in the Vrbovecký brook (Czech Republic). The larvae were hand‐picked at 6‐hour intervals. The ratio maximum foregut diameter/head capsule width was used to determine gut fullness and the contents of larval foreguts were analyzed using a millipore filter technique. One‐way ANOVA revealed significant differences in gut fullness among instar V larvae collected at different times. Guts were fuller in the larvae collected at dusk and at dawn, indicating high crepuscular activity. No significant temporal differences in gut fullness were recorded for instar IV larvae. There were no significant differences in foregut contents among instar V or among instar IV larvae collected at different times. However, the difference between foregut contents of instar V and IV larvae was significant. Amorphous detritus was the most important food source for instars IV, whereas instars V fed mainly on animal food and cellular detritus. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)