QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Douglas, R. H. Search for Related Content PubMed Articles by Douglas, R. H. Social Bookmarking                         What's this?

Journal of Experimental Biology 96,377-388 (1982)
Published by Company of Biologists 1982

An Endogenous Crepuscular Rhythm Of Rainbow Trout (Salmo Gairdneri) Photomechanical Movements

R. H. Douglas ¹

¹ Department of Biology, University of Stirling, Stirling FKg 4LA, Scotland; Universität Ulm, Abt. Klinische Morphologie, 79 Ulm (Donau), Neubau Oberer Eselberg, West Germany

1. The position of the epithelial pigment and cones in the retina of Salmo gairdneri was determined during extended periods of darkness in fish entrained to both artificial and natural light/dark cycles.

2. An endogenous rhythm of such photomechanical movements, unique among species so far examined, was observed in both groups of fish, with two peaks of light adaptation coincident with dawn and dusk.

3. It is suggested that such an apparently non-adaptive physiological rhythm is related to the behavioural pattern of trout and reveals a basic crepuscular organisation.

4. No endogenous rhythm was observed in continual light.

5. These results suggest that control of photomechanical changes in rainbow trout has two components: an endogenous component, that causes the bimodal pattern in maintained darkness, and a direct effect of light, that maintains light adaptation throughout a normal day.

Note:
^*Present address: .

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?