This practical involves offering several different environments to a number of freshwater shrimps. The shrimps should move to the area in which they feel more comfortable.
A standard tray can be used as the choice chamber. The tray should be separated into four sections into which various surfaces and textures should be placed.
Equipment typically required (per set):
Freshwater shrimps can be obtained from aquarium shops and should be purchased as close as possible to when the practical is to be conducted. In the wild, the shrimps live at the bottom of rivers and scavenge for food scraps. Each of the environments in the 'choice chamber' represent places that shrimps may come into contact with in real life.
- Pebbles (small)
- Small stones
- Freshwater shrimps
Fresh water should be poured over the four environments so that they are all approximately 3-4cm under water. Ensure the tray is equally lit, e.g. if in direct sunlight, make sure that each environment is as exposed.
20-30 shrimps are usually placed into the centre of the tray so they have a free choice which environment to choose. They are left for 45 minutes to an hour and then the shrimps in each area are counted.
Shrimps usually prefer the clay/mud area.
After the practical, the pebbles and sand can usually be sifted and reused.
Typical technician preparation time: 10-15 minutes per tray.