The Netherlands 2

Pauline Strijdhorst (18)

City/Region: Krimpen aan den Ijssel, Zuid-Holland E-mail: petrastrijdhorst@hotmail.com Hobbies: Riding horses, swimming and reading Career: Physiotherapist School: Comenius College

Marloes van der Waal (18)

City/Region: Krimpen aan den Ijssel, Zuid-Holland E-mail: h.van.der.waal@hccnet.nl Hobbies: Playing the transverse flute, drawing and dancing Career: Midwife School: Comenius College

Influence of Light on the Swimming Behaviour of Fish

Having to pass an exam is not a bad excuse for taking up research as Pauline and Marloes found when they ended up studying fish. Fish prefer natural colours, the two girls claim. This they concluded because the fish spent most of their time in the green part of their aquarium, less time in the yellow part, even less in the blue part - and the least amount of time in the red part. When they shone a light from beneath the aquarium the fish found this strange and stayed still together in one group. When the light came from one side of the aquarium the fish were curious and swam towards the light to see what was happening. Then to see how the fish might react they used a strobe similar to the one that flashes on and off rapidly at discos to observe what they might do. They perhaps not unnaturally feared this strange phenomenon, but at the same time they were also curious and swam to the side of the strobe's light to have a better look.