A Japanese research team has trained goldfish to distinguish between Bach’s Toccata and Fugue in D Minor and Stravinsky’s The Rite of Spring. The fish would bite a bead suspended in their tank when they recognised one of the pieces.
"The scientists, whose research is published in the journal Behavioural Processes, first trained four goldfish to bite the bead and receive a pellet of food from a tube in their tank. They were then divided into two groups and were trained to do this when either 20 second long clips of Bach or Stravinsky were playing. Between each clip the music was muted for varying amounts of time – meaning with each session the clips of music the fish heard were not consistently the same. The goldfish were then trained to either bite the bead to one piece of music and to do nothing when the other was playing. The researchers found that the fish were able to distinguish between the music in 75% of cases over three sessions. However, the fish were not fast learners – it took more than 100 training sessions before they were able to distinguish the pieces."