Chad Clark's Open Journal : 2009-10-20

1) Fish are able to learn behaviour to get food.

This New York Times article reports fish can learn.

  [A] research team led by Ulrike E. Siebeck at the University of
  Queensland in Brisbane, Australia, trained damselfish to feed from a
  feeding tube to which they attached a variety of visual stimuli. The
  latter included a three-dimensional latex disc, a two-dimensional blue
  disc painted on a plastic board, or black circles or propeller patterns
  on white boards. The fish were rewarded with food when they repeatedly
  tapped the stimulus — not the tube — with their snout or mouth.
  
  Remarkably, the fish also learned when the food reward was delayed and
  delivered far from the stimulus. The damselfish exhibited what is called
  anticipatory behavior, in that they would tap the image and then swim
  quickly to the other end of their tank in anticipation of their food
  reward.
  
  ...
  
  The fish were even better at color discrimination, tapping the correct
  target more than 90 percent of the time.