Modified Staaland Device with Automatic Recording Techniques for Determining Salinity Preference in Fishes

Abstract
Modifications were made in the design and filling procedure of the Staaland device used to study salinity preference in fish. Two photographic recording techniques that eliminate the need for direct observation of fish activity and allow for continuous monitoring of fish movement throughout several daily photoperiodic cycles are described. Key words: salinity, preference, gradient, fish, photography, recording