Brine Shrimp Lab Report

The purpose of this lab is to determine the effects of various concentrations of salt solution on the development of brine shrimp larvae. The hypothesis was that if the salinity level is 10% higher then others then more eggs will hatch. The independent variable is the varying concentrations of salinity, and the dependent variable is how many eggs will hatch.

Materials

1. 6 toothpicks
2. brine shrimp eggs
3. 150 mL of 10% noniodized salt solution
4. 150 mL of tap water
5. 1 100 mL graduated cylinder
6. 1 10 mL graduated cylinder
7. 1 cm ruler
8. 6 petri dishes
9. Black denim

Procedure

First you arrange the petri dishes in order of increasing concentration: 0%, 2%, 4%, 6%, 8% and 10%. Then using the graduated cylinder you pour 30 mL of tap water in the 0% dish, 24 ml of tap water and 6 mL of salt solution in the 2% dish, 18 mL of tap water and 12 mL of salt solution in the 4% dish, 12 mL of tap water and 18 mL of salt solution in the 6% dish, 6 mL of tap water and 24 mL of salt solution in the 8% dish, and 30 mL of salt solution in the 10% dish. Next make a mark on 6 toothpicks up to the 5 mm mark Then using the toothpicks as a spatula, remove the brine shrimp eggs from the vial, and sprinkle them into the water in each of the 6 petri dishes. Be sure to use a different toothpick for each petri dish. Cover the petri dishes with some black denim, and set them aside for 2-3 days.

Data

Group Data

Class Data

Analysis

The purpose of this lab was to determine the effects of various concentrations of salt solution on the development of brine shrimp larvae. The hypothesis was that if the salinity level is 10% higher than others then more eggs would hatch. By the data, the hypothesis was not supported. The 10% petri dish hatched no eggs, while the 0% petri dish hatched the most eggs. But the eggs should've hatched the most in the 4% petri dish. There are many reasons why this did not happen. For one, when we counted the hatched shrimp, we took an estimate, not an exact amount. Also, there is a good chance that there weren't the same amount of shrimp in each dish. There was also the fact that salinity probably wasn't exactly the percent it was supposed to be, and there was some splashing of the water, which helped throw off the salinity level.

Questions

1. A different toothpick should be used for each petri dish because once dipped in one petri dish, it picks up residue from that dish, which could carry over into the next dish, which throws off the salinity level
2. The salt solution that represented the control in this experiment was the 0% solution
3. The factor that was varied in this experiment was the salinity level of the water
4. The salt concentration that we found best for hatching brine shrimp eggs was 0% salinity
5. The results of our experiment didn't support our hypothesis because we predicted that 10% would be the best, while the exact opposite, 0% turned out to be the best
6. You can insure that your experimental results are valid by eliminating the errors that could be made and repeating the experiment multiple times

Conclusion

In this lab, I learned that brine shrimp hatch the best in 4% salinity level water, and that errors during the lab can throw off your data.