Salinity and Hatching Brine Shrimp Eggs
Great crustaceans! Does more or less salt in the water create super shrimp? Make your own seawater and discover how salt helps or hinders hatching.
Brine shrimp are tiny crustaceans that live in salt water. This means that they’re related to crabs, lobsters, and other shrimp. However, brine shrimp are much smaller than other shrimp, and they make intriguing pets. In this experiment, you’ll see how different amounts of salt change the hatching rates of brine shrimp.
The ocean and some lakes are salty, and this salt comes from the rocks in the water. You can’t see the salt in the water because it is dissolved, but it has a big impact on the creatures that can live in an environment. The amount (or concentration) of salt in the water is called salinity.
Brine shrimp have an interesting life cycle. The adult shrimp lays cysts that contain baby shrimp. These cysts have a superpower: if conditions in the environment are bad, they will stay dormant for a while and wait until conditions improve before they hatch.
For this experiment, you’ll get three different containers and make them each into a different ocean. Create a hypothesis, your best guess as to what is going to happen. Will the brine shrimp prefer water that’s very salty, somewhat salty, or not very salty?
What is the ideal salinity for hatching brine shrimp?
- Three clear, one quart plastic containers
- Three quarts of distilled water
- Four tablespoons of aquarium salt
- ¾ tablespoon brine shrimp eggs
- Wooden spoon
- Magnifying glass or microscope
- 3 petri dishes
- Fill each container with a quart of warm distilled water.
- Get your aquarium salt, and stir half a tablespoon of salt into the first container, one tablespoon into the second, and two tablespoons into the last. Label the containers.
- Stir until the salt is dissolved, and check for crystals on the bottom before you go on.
- Now it’s time to add the baby shrimp! Stir in a quarter tablespoon of eggs in each container.
- Put the containers on a sunny window ledge or under a light. Make sure that the water stays warm, but not too hot. It should be room temperature. Why is the room light and at room temperature important?
- Gently stir the water every few hours. Why do you need to stir the water?
- Over the next two days, watch the baby shrimp hatch. Take notes about the progress in each container.
- After 48 hours, take a teaspoon-sized sample from each container, and place the sample in a small, clear container such as a petri dish.
- Look at each sample with your magnifying glass and see how many shrimp have hatched. If you have a microscope, this is a good time to use it, because you’ll be able to see the shrimp babies very clearly.
- Go back the next day and take another sample. Which container has the most baby shrimp?
Brine shrimp do best at a salinity of 1 2/3 tablespoons of salt per quart of water.