Girella nigricans

     During his doctoral research at Scripps Institute of Oceanography, Ken Norris dedicated himself to the study of the Opaleye Perch (Girella nigricans), trying to discover why Peter Duodroff made the conclusion that Girella preferred water at exactly 79℉. In order to test the hypothesis, Norris built a chamber with 79℉ water calling it the ‘ichthyothermitaxitron.’ Through his machine, he noticed that the Girella consistently moved towards this temperature comcluding this high temperature mimicked the conditions of the tidepools which lures these fish higher up the tidepools where there was more sun, meaning more food.     

     Through further observation of the tidepools and tests with his machine, he discovered their eating and growth patterns. In his machine he noticed that at 79℉ they would eat compulsively, naming this point the “temperature of maximum feeding.” The higher temperature is typically at the higher part of the tidepools where algae is getting more sun. Norris noticed that despite the eating, they would never grow at this temperature. Through more studies, it was found they would only grow at a lower temperature, meaning further away from shore where the water was cooler, tides were lower, and predators wouldn’t be able to get them as easily.