Brine Shrimp Hatching Experiment

Wherever salt water is evaporated on a large scale, or salt lakes develop, brine shrimp will eventually appear. How do they get there? Certain birds visit salt waters – shorebirds such as gulls and stilts, for example. Could they transport the adult brine shrimp or eggs? Could brine shrimp eggs travel by wind?

An interesting fact to remember is that although brine shrimp grow very well under artificial conditions, brine shrimp are not found in the open ocean. This is because the brine shrimp’s only defense mechanism against predators (fish and other invertebrates) is hyper-saline bodies of water.

For this reason, brine shrimp have developed the most efficient osmo-regulatory system in the animal kingdom. Ask the pupils to provide an explanation of why brine shrimp are present only in salt ponds and soda lakes and not in the ocean.

Get Help With Your Essay

If you need assistance with writing your essay, our professional essay writing service is here to help!
Find out more about our Essay Writing Service

Use a glass container as a hatching tank for the brine shrimp, either a wide-mouth quart jar or a shallow glass pan at least two inches deep (this will work best). Fill the container with one quart of salt-water solution: mix 1 to1-1/2 teaspoons of sea salt mixture or non-iodized table salt per cup of bottled water. (If you want to use tap water, let it sit for an hour so the chlorine settles. You can also use rock or aquarium salt.) The shrimp will die in salt water that is either too weak or too strong.

Sprinkle about one sixteenth of a teaspoon of brine shrimp eggs into the dish: you don’t need to cover more than one square inch on the surface of the water. Leave the container in a room where bright sunlight can reach it. Your brine shrimp should start hatching in just 24 hours!

The shrimp will live 1-3 days without food. If you want to keep them longer for a more in-depth study, feed them a very tiny amount of yeast – a few “grains” as needed. You might also need to change the water occasionally, if it gets cloudy. Clean out unhatched eggs from the top of the container, which will allow more oxygen to get into the water.

Observing Brine Shrimp

You can study your brine shrimp close up with a magnifying glass, stereo microscope, or compound microscope. Use a pipet or medicine dropper to “catch” some of the shrimp and transfer them with sufficient water into a petri dish for easy observation. Look at them closely with low power (10-30x) magnification. What parts of the brine shrimp can you identify? What are their swimming habits? Eating habits? How do they use their phyllopods? How do they respond to light? If you can, compare the larval stage with the adult stage. Keep track of your observations in a notebook and include sketches of the shrimp.

Learn about the effects of the surrounding conditions on brine shrimp! To start, test the pH level in the brine shrimp’s tank water: ideal conditions are a pH of around 8, but no lower than 5 and no higher than 10. Use pH paper for the test. To raise the pH level in the tank, add a little bit of baking soda.

Discover more with a project where you change the tank environment by adding pollutants. Transfer about an equal number of brine shrimp to several petri dishes to be your test samples. Try adding 1-3 drops of a different solution to the water in each petri dish: vegetable oil, soap, vinegar, ammonia, or anything else that comes to mind. Observe the samples at low power magnification and record what’s going on. How do the pollutants affect the sample? Is there a difference visible in twenty minutes? One hour? Three? How might you counteract the pollutants?

You can also try hatching several batches of shrimp at a time, using different hatchery conditions for each batch. Fill 3-4 petri dishes with different solutions: you might use plain tap water, water with a low pH (acidic), and regular salt water to be the control that you can compare the results to. Before you start, hypothesize which solution will have the best results and which will have the worst. Sprinkle a small amount of eggs into each dish. After 24 hours, check on the dishes again. Has anything happened? What are the results after 48 hours? 72 hours? Use a magnifying glass for your observations, and make sketches. Were you right about which solutions would work best and worst? How do you think factors such as temperature (colder or warmer) or more or less light might affect the hatching success rate of the brine shrimp?

PROBLEM STATEMENT

What is the total number of successful hatching of brine shrimp?

HYPOTHESIS

The number of hatching is the most at the temperature of 30 ͦ C. number of hatching is the lowest at 34 ͦ C.

VARIABLES

Manipulated: temperature of incubation

Responding: number of eggs hatch

Fix: concentration of salt solution, number of eggs

APPARATUS AND MATERIALS

Brine shrimp cysts, 25ml salt, 100cm³ dechlorinated water, 40cm³ beaker of salt water, 100cm³ beakers, water baths of temperature 30 ͦ C and 34 ͦ C, stirring rod, forceps, pipette, microscope, ¼ saptula of eggs

PROCEDURE

Place 25ml of sea salt into a 100cm³ beaker.

100cm³ of de-chlorinated water and stir until the salt is completely dissolved.

The beaker is labeled with the group name, class and the temperature in which it will be tested.

¼ saptula of eggs is added into the beaker.

Placed the beaker in incubator of temperature 30 ͦ C, 34 ͦ C and at room temperature. The cysts are left for one night.

On the following day, the cysts is calculated. Stir the solution containing the cysts gently to make sure they are evenly distributed. 0.5 cm³ of the solution is pipetted and put into Petri dish.

Calculate the total amount of the cysts which is hatched and unhatched at all temperature under light microscope. The experiment is repeated three times to get the average value of the amount calculated.

all the values calculated is multiplied by 50 to get the total amount of brine shrimp in 25ml of solution.

DISCUSSION

According to the tabulated data above, total cysts hatched is the highest at temperature of 30 ͦ C because higher temperature is needed to make the surrounding warmer and suitable for hatching. The lowest eggs hatch being recorded is at temperature of 34 ͦ C because the temperature is too high. The eggs, being the enzyme might be denatured at this point and most eggs do not hatch.

There are more eggs that has not been hatch compared to those which has hatch. This might be due to the short term experiment. The eggs are allowed to soak in the solution for only a day and most of them have not hatch yet.

Conducting this experiment has risen up a few conflict and ethical issue. The cysts which has and has not hatched will be thrown after the experiment end. For public, it is not ethical to kill animal which is still alive and used as a study purpose. Although they are tiny but they do play their part in food chain. They don’t have right to live freely as other organism do.

But, for scientists, conducting an experiment on them may bring good advantages to human. Human will get the beneficiary as new medicine and discovery is discovered without involving any human life in the research. People doesn’t put too much attention when small animal like bribe shrimp is used in the experiment.

LIMITATION

The size of brine shrimp eggs are too small and almost impossible to be counted manually. Hence, only ¼ spatula of the eggs are used in approximation. But there is limitation in using approximation. The number of cysts used is not the same in each test tubes makes the result. This makes the result less reliable. A larger number of cysts is needed because the results of experiment may vary and by using big group of sample, the result may be more reliable.

There might be some mistakes while calculating the number of cysts that has hatched or not because the number of eggs per o.5ml is a lot and to calculate them under light microscope is almost impossible. Some students taking the number of which can be seen under lense, some takes average. The likelihood to get the real number is low.

In counting the number of the eggs, the average is taken. Only 0.5ml out of 25ml is being used to be observed under the microscope. The distribution of the eggs in the solution might not be the same even after it has been stirred using glass rod.

SOURCE OF ERROR

The test tube which should be put under room temperature is being put in the laboratory which has air conditioner. This makes the temperature of surrounding lower than the room temperature and affect the result of experiment in making a conclusion that the earth is facing global warming. Hence, we are not sure whether or not, the room temperature has risen.

Since they are too small, somehow, their hatched eggs are counted as unhatched eggs. This happens as there are no big difference in structure of the hatched and unhatched eggs. This may lead to wrong counting of the result and will affect the experiment.

PRECAUTION STEP

Be careful when pipetting the cysts because they are so small and might be easily get hurt. They need to be handled with care and gently.

use a low light power while using microcopeas higher temperature might gives effect on the brine shrimp.

CONCLUSION

The hatching success of the brine shrimp is the highest at 34 ͦ C