My Pet Fish

In order to brighten up the living room we bought a pet fish and an aquarium to put it in. The fish was brightly coloured and I often liked to watch it as it swam contentedly round and round its little rectangular tank of water. It was so friendly and tame that it was happy to take food directly out of my hand. Having an interest in the theories of Charles Darwin, as an experiment one day I decided to see how the fish would adapt to change. So each day I would remove a tablespoonful of the water and replace it with a tablespoonful of seawater. This went on for several months until eventually the fish was happily swimming around in pure seawater.I decided to reverse the process, and each day, I would remove a tablespoonful of seawater from the tank and replaced it with a tablespoonful of fresh water until the water in the tank was completely returned to fresh water. The fish was none the worse for his experience.Encouraged by this success I decided to try a further experiment. Each day I would remove a tablespoonful of the water from the tank to see if the fish could adapt to the changed circumstances of reduced water levels. Although the fish had difficulty adapting at first it was eventually able to lie on the bed of the tank and breath air. Later I decided to move the fish to a disused budgerigar cage and was surprised to see that the fish had adapted to its new circumstances and was cheerfully hopping from perch to perch, ringing the bell, and playing on the swing. The fish lived like this for several months until sadly one day it fell from its perch straight into the bowl of drinking water and drowned.