A METHOD TO MEASURE BEHAVIORAL RESPONSE TO AN OLFACTORY STIMULUS

A behavioral analysis method was developed to measure the effectiveness of various feed attractants as well as study the difference in olfactory-stimulated, behavioral response of fish fed alternative diets either lacking in taurine, or with taurine added.

Feeds are being developed that replace traditional fish-derived protein with plant protein. Currently, aquaculture feeds formulated without fish protein do not perform as well as those that are. Some additives however, may be able to increase food acceptance and growth.  A multi-chambered, circular tank is divided into six segments by water currents so that test substances can be contained within one segment yet fish can move freely between them (Figure 1). Individual fish placed in this system were monitored by recording location in the tank segments before and after introduction of a putative chemoattractant. Presence of the fish in the exposure segment was then compared between pre and post-exposure recordings. Squid extract was used to test the effectiveness of the experimental design.

Without squid extract present, fish tend to swim in circles around the periphery of the tank. With the squid extract present, fish changed behavior and spent more time closer to the center of the tank. The amount of time fish spent in the central sections of the tank was compared with and without odor present (Figure 2.).

In conclusion, this radial tank design has been validated as an effective platform for behavioral attractant studies. A reference odorant has been identified that is comparable to already published attractant work. Experimental protocols have been established and the groundwork laid for further experiments with a variety of odorants.