Figure 1.

Behavioral tank from three perspectives (not to scale). Small notches and square between sections labeled 1 and 2 indicate the approximate location of the hole in the clear barrier: a 2.5 cm × 2.5 cm square hole placed approximately 2.5 cm from the surface of the water and 2.5 cm from the observer side of the tank. The left-most compartment in the top and side observer views (section 1) represents the start compartment, in which the subject started. The flowerpot (grey shaded object) in the middle section in the top and side views (section 2) was the goal for the subject: the target compartment. The flowerpot serves as a motivating factor to males as flowerpots are normally associated with a territory to claim. In addition, it is closer to the female fish. Since male fish had been kept in social isolation prior to placement in the behavioral tank, close proximity to females, is also motivating (Fernald and Hirata, 1977; Hofmann, Benson, and Fernald, 1999). Between compartments 1 and 2, a removable opaque barrier was present for an acclimation period of one minute. The right-most section in the top and side views (labeled “3”) represents the compartment in which 10 females were placed. The barrier separating the target compartment from the female compartment was clear and perforated, with holes drilled into the barrier as indicated by small Xs. All barriers permitted the flow of water between compartments.