Abstract

Nymphs of Baëtis rhodani (Pictet), Ephemerella ignita (Poda), Ecdyonurus venosus (Fabricius), Rhithrogena semicolorata (Curtis), and Heptagenia lateralis (Curtis) showed a similar endogenous rhythm of activity under conditions of natural illumination, continuous light and continuous darkness; and were most active at night when they moved from the lower to the upper surface of the stone. The nymphs were positively thigmotactic and negatively phototactic in flowing water, but these taxes and the endogenous activity rhythm of all species except Heptagenia lateralis changed markedly when the flow of water ceased.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.