Lab Report: The Effects of Salinity on the Hatching of Brine Shrimp

To determine the effects of salinity on the hatching of Brine Shrimp, one must test the eggs growth under differing levels of salinity with all other variables remaining constant. If the Brine Shrimp are exposed to higher levels of salinity then more eggs will hatch. The direct variable in this experiment will be the levels of salinity that the Brine Shrimp are exposed to. The indirect variable will be the amount of Brine Shrimp eggs that hatch in the water and salt solution. To ensure these are the only variables in the experiment, everything else must remain constant. The type of water, type of salt, and temperature will all be constant. The control group for this experiment will be the Petri dish with just distilled water and no salt. This gives something to compare the results to.

Materials:

1. 150ml of distilled water to mix in with the salt solution to create varying levels of salinity
2. 150ml of 10% non iodized salt solution to mix with the distilled water for the same reason
3. 6 toothpicks to use as spatulas to remove the Brine Shrimp eggs form the vial and place in the water in the six Petri dishes
4. Brine Shrimp eggs to use as the specimen being tested
5. 100ml graduated cylinder to measure the amounts of liquid in tens
6. 10ml graduated cylinder to measure the amounts of liquid in ones
7. 6 Petri dishes to separate the different environments for the Brine Shrimp eggs
8. A cm ruler to mark off five mm on the toothpicks

Procedure:

• Label 5 mm on each toothpick
• Arrange the Petri dishes in order of increasing concentration: 0%, 2%, 4%, 6%, 8%, and 10%
• Using the graduated cylinder, pour 30 ml of distilled water in the 0% dish
• Pour 24ml of distilled water and 6ml of the salt solution in the 2% dish
• Pour 18ml of distilled water and 12ml of the salt solution in the 4% dish
• Pour 12ml of distilled water and 18ml of the salt solution in the 6% dish
• Pour 6ml of distilled water and 24ml of the salt solution in the 8% dish
• Pour 30ml of the salt solution into the 10% dish
• Clean up dishes

Data:

The Brine Shrimp eggs hatched in every solution however depending on the level of salinity, there were different results. In the solution of pure distilled water, the class data showed that twenty one eggs hatched. In the two percent Petri dish one hundred eggs hatched. In the four percent dish, ninety eggs hatched. In the six percent dish, thirty hatched and in both the eight and ten percent dishes only one egg hatched.