What is the optimal environment for hatching brine shrimp? Using a scaffold, students design and conduct experiments testing the effect of a single abiotic factor on brine shrimp cyst hatch rate. Pool results from the class to determine the optimal environment for hatching these resilient organisms.
- Abiotic factors (light, temperature, pH etc.) affect the survival of species within an ecosystem.
Prep time: 20 min to gather supplies
Class time: 90 min to design and set up experiments
Time for brine shrimp to hatch: 1–2 days
- Abiotic factors
- Brine shrimp life cycle
For the Class
- Student Pages
- 1 g brine shrimp cysts in salt solution
For Each Lab Group
- small Petri dishes
- soft, white, absorbent paper towels (uniform embossing works best)
- small pipet or dropper
- 10 mL of 3% salt solution
- microscope or hand lens
Optional Materials for Student–Designed Experiments
- Petri dishes or other shallow, wide containers, test tubes, graduated cylinders
- UV light source (UV light box or goggle sterilizer)
- incubator, refrigerator
- acidic and basic solutions (vinegar, bleach, etc.)
- aluminum foil
- non–iodized salt
- "pollutants" (household pesticide and herbicide, fertilizer, etc.)
- aquarium aerator, flexible tubing
Before doing the lab
- Order brine shrimp cysts (often referred to as brine shrimp eggs) from any biological supply company (see quantity at right). Cysts will come dried and will keep for years.
- Gather lab materials your students may use to conduct their experiments. Examples are included at right. See the table on page 7 in the Hatch–a–Cyst Teacher Guide for more information.
- One hour before the lab: Hydrate 1 g brine shrimp cysts in 500 mL of 3% salt solution.To make the salt solution, dissolve 15 g of Instant OceanTM or non–iodized salt (such as sea salt) in 500 mL of tap or deionized water. Prepare additional 3% salt solution as needed, enough to give 10 mL to each lab group.
- Give each student or group of students a copy of the Hatch–a–Cyst Student Pages.
- Use the worksheets as a scaffold for conducting this exercise. See the annotated Hatch–a–Cyst Teacher Guide document for suggestions, background information, tips and tricks.
- Be sure that students or groups of students test a variety of individual abiotic factors in each class. Wrap up the activity by pooling the students' experimental results to determine the optimal environment in which to hatch brine shrimp.