Zebra fish learnt and memorized which end of their tank food would be delivered after a tap on the glass of the tank. The fish presented themselves at feeding at the correct end, when the cue was not given in later trials.
The fish were able to remember to go the right end for 10 days after their initial training. They were able later to re-learn to present themselves at the opposite end after the training changed.
"Fish were fed on alternating sides of a divided fish tank, with a red card displayed on one side serving as a visual means of orientation. Although responses were recorded at cue (light tap on the tank), 5s after cue (as food was delivered), and 5s after food delivery, the learning test was choice of a correct side of the tank to receive food."
"Data collected from 11 separate experiments indicated that zebrafish learned to alternate for a food reward. Further, statistical analysis showed that the zebrafish learned the task in the first half of the experiment."
"Zebrafish could recall the task after a short period of 10 days with no testing. The alternating behavior was extinguished by withholding the food reward. Thus, the spatial alternation task can be learned easily by zebrafish."
"A correct response was considered to be the physical presence of the animal on the side of the tank used for food presentation during that trial."