Hatching Brine Shrimp Environments

Purpose Observe and compare the hatching of brine shrimp eggs in four salt concentrations Organize data from an experiment Determine the range of salt tolerance for brine shrimp hatching Draw conclusions about the optimum salt conditions for brine shrimp hatching Design an investigation to test the viability of brine shrimp eggs. Use scientific thinking process to conduct investigations and build explanations: observing, communicating, comparing, organizing, and relating.

 Salinity: how salty water is, the concentration of salt in water

BBrine Shrimp: tiny animals related to crabs and lobsters. Brine shrimp are found in salt ponds and salt lakes.

Discussion: What are the different types of environments that we have been investigating? What organisms live in each environment? What do you think a salt pond environment is like? What organisms do you think might live in a salt lake or a salt pond?

Do you think the amount of salt in the water ever changes? Do you think the amount of water has an effect on organisms that live in the water?

In a controlled experiment one variable (salt) is isolated and tested. All other variables are held constant (controlled). How can we find out if salinity affects brine shrimp hatching?

Which environment do you think will hatch more brine shrimp? In Your Journal

 Optimum: environmental conditions are the best conditions for an organism

What is the optimum environment for hatching brine shrimp eggs?

Part 3: Determining Viability Get hatchery tray and make observations in your journals.

Part 3: Determining Viability Viability: When something is alive and able to function and grow, it is said to be viable. Viable means alive or able to grow.

Part 3: Determining Viability Do you think the eggs that didn ’ t hatch are viable or dead? How could you find out if the eggs that have not hatched in your cups are still viable?

Part 3: Determining Viability Each group needs to discuss a plan to test viability. Add salt and/or water to the “ extreme ” cups to bring the salt concentration within the range of tolerance for hatching. Write out your plan in your journals including the amount of salt or water you plan to add, and the reason for adding that amount. Re-label your cups to reflect the amount of water/salt contained in the cup.

Viability Results Were the eggs in the 0-spoon and 6- spoon cups viable? Was the hatching robust or did only a few hatch? What advantage is it to the brine shrimp to postpone hatching in salt solutions that are very diluted or very concentrated? In Your Journal

 Viable: means alive and able to grow

What strategies enable an organism to survive outside its range of tolerance? Brine shrimp eggs remain viable but don’t hatch until the conditions are within the range of tolerance.

Materials: 4 plastic cups and lids 4 sticky notes 1 cup of salt, kosher 1 brine shrimp eggs in vial 1 mini-spoon 1 spoon 5-ml 1 craft stick 1 FOSS tray 1 container 1-liter 1 beaker, 100 ml In Your Journal

Problem: Does the amount of salt in water affect the organisms that live there? Get 4 cups and label them as follows: 0 spoons salt 2 spoons salt 4 spoons salt 6 spoons salt Measure 150 ml of water into each cup Measure salt into the labeled cups using 5-ml spoon. Put lid on cup and swirl the water to mix the salt. In Your Journal

Problem: Does the amount of salt in water affect the organisms that live there? Put 1 level mini-spoon of brine shrimp eggs in each cup an gently mix. Place all 4 cups in the recess on the FOSS tray.

Part 2: Determining Range of Tolerance Day 1Day 2Day 3 Day 4 Copy into your journal and answer the following. What day of your experiment did you first notice hatching? In which container did you first notice hatching? 0 spoons 6 spoons 4 spoons2 spoon In Your Journal

Part 2: Determining Range of Tolerance  Part 2  Copy this chart into your journal and record the number of eggs that hatched in each cup. Make an “ X ” in one box for each salt condition 0 spoons2 spoons4 spoons6 spoons MOST SOME NONE Day _____________________ Salt Conditions In Your Journal

Discussion Do brine shrimp-eggs need salt in order to hatch? Were there cups that had conditions favorable for brine shrimp hatching? Which ones? Were there cups that had conditions that were unfavorable for brine shrimp hatching? Which ones?

Discussion Can you give brine shrimp eggs too much salt? Can you determine the range of tolerance that brine shrimp eggs have for salt? Which conditions seemed to be optimum (best) for brine shrimp hatching?