Modeling Krill Behavior:
How do brine shrimp react to physical stimuli?
Materials (for each group of 3/4 students):
- microscope or hand lens
- brine shrimp eggs
- plastic bag
- light source
- petri dish
- ice cubes
- cover glass and slide
- aluminum foil
- glass rod
- graduated cylinder
- medicine droppers
- bar magnet
- Activity 1.1.1 Student Worksheet
- Make a salty ocean for brine shrimp to swim in by adding 3.5 grams
pure (not iodized) sodium to 1,000 milliliters of water. (3 or 4 tablespoons
salt in a gallon of water)
- Fill a petri about half way with the salty water to make a fish bowl
for the eggs.
- Touch one end of a glass rod to the salt water to dampen it and then
touch the dried brine shrimp. The damp rod will pick up a bunch of eggs.
Transfer eggs to the petri by stirring the rod end through the solution
in the petri. Cover the petri dish.
- Look at the eggs through magnification every 24 hours and carefully
draw their appearance. When you have lots of brine shrimp swimming around,
you are ready to conduct experiments.
Brine Shrimp Observations:
- Fill two eyedroppers with crowds of brine shrimp.
- Wrap aluminum foil around one eyedropper to prevent light from entering.
Leave 5mm at the tip free of foil.
- Hold both eyedroppers near a light bulb for at least ten minutes without
moving them. Where do the brine shrimp go in each eyedropper? (Be careful
not to let the eyedroppers get hot.) (effect of light)
- Squirt the brine shrimp back into the petri dish and get new samples
of brine shrimp in each eyedropper.
- Set one eyedropper horizontally on a large ice cube and prop the other
horizontally on your lab table for at least 5 minutes. What response do
you see? (effect of temperature)
- Squirt the brine shrimp back into the petri and get new samples of
brine shrimp in each eyedropper.
- Hold one eyedropper vertically and the other horizontally for two minutes.
Do you observe a difference in brine shrimp behavior? (effect of
- Set one eyedropper horizontally on a magnet and hold the other horizontally
for two minutes. What response do you get? (effect of magnetism or
Which stimuli appeared to have the most effect on the behavior of brine
How might your observations be applied to the movements/habits of krill
in the oceans around Antarctica?
Student Worksheet #1.1.1