A Two-Choice Water Recirculation Tank for Assessing Chemosensory Preferences of Landlocked Sea Lampreys

Abstract
A two-choice preference tank designed for assessing the responses of landlocked sea lampreys (Petromyzon marinus) to potential chemical attractants and repellents is described. The solutions in the experimental and control compartments of the tank are recirculated at the same rate permitting small quantities of substances to be tested at constant concentrations. No mixing between the two compartments was observed during 90-min dye tests. This tank should be suitable for preference tests with other aquatic organisms, similar in size to landlocked sea lampreys. Color-coded fluorescent tags, which permit identification of individual lampreys under ultraviolet illumination, and a simple timing system, which allows the time spent in the experimental compartment to be monitored for six lampreys, are also described.