Brine Shrimp
Brine shrimp are tiny crustaceans that inhabit salty waters around the world, both inland and on the coast. The
average adult brine shrimp is 0.3-0.5 inches long. Brine shrimp are typical primitive arthropods with a segmented
body with broad leaf-like appendages. The body usually consists of 19 segments. They are most easily noticed in
the water by looking for their pulsing swimming motion. Brine shrimp can survive in water with varying salinities
and are found in lakes, brackish water and coastal regions. Brine shrimp feed on algae and are food for a variety
of aquatic life & birds.
The life cycle brine shrimp begins from a live birth or from a
dormant cyst that contains an embryo in a suspended state
of metabolism (known as diapause). The cysts are very
hardy and may remain viable for many years if kept dry.
Whether baby brine shrimp hatch from a cyst or are born
live, in its first free- swimming period it is called a nauplius
(plural: nauplii). The rate at which it develops through the
rest of the stages in its life cycle is affected by salinity,
water temperature, and food availability. The emerging
nauplii feed on algae, providing energy for the 12-24
molting stages a brine shrimp goes through to reach
maturity, a process that takes 2-3 weeks depending on food
availability and temperature. The average adult will
produce around 8 broods, generally a combination of both
egg and cysts.
In this experiment you will be provided with 3 concentrations of salt water and brine shrimp cysts. We will
observe each beaker for several days for the emergence of the nauplii.
Problem: (What question do you want to find out about?)
Hypothesis: (What do you believe is the answer to the question and why?)
Experiment: (Explain step by step your testing procedures & material needed)
Materials: 2 beakers, brine shrimp cysts, 1 toothpick, WEAK salt solution (2 g salt in 100 ml H20), STRONG
salt solution (4 g salt in 100ml H20), hand lens, wax marking pencils. Note: your control will be set up by
your instructor and shared between the class periods.
Procedures:
1.
2.
3.
4.
5.
6.
7.
Obtain 2 beakers and label each with your group number. Label one WEAK and the other STRONG.
Measure 100 ml water into each beaker.
Measure 4g and 2g of salt into separate cups.
Pour salt into each beaker and gently swirl to mix the solution.
Using a toothpick that has brine shrimp eggs on the tip, add the eggs to each solution by swirling the toothpick into
the salt water.
Observe each beaker daily.
Count and record the number of shrimp you observe in the beaker. If there are too many you may have to sample the
solution and estimate the number of brine shrimp in your beaker.
Data:
Qualitative:
Quantitative: (Please set up a data table. You will be observing all 3 salt concentrations for 5 days)
Conclusion: (write a conclusion in paragraph form that indicates whether or not your data
supports your hypothesis and why)
___________________________________________________________________________________________________________
___________________________________________________________________________________________________________
___________________________________________________________________________________________________________
___________________________________________________________________________________________________________
___________________________________________________________________________________________________________
___________________________________________________________________________________________________________
___________________________________________________________________________________________________________
1. What were the controlled variables (constants)?
2. What was the independent (manipulated) variable?
3. What is the dependent (responding) variable?
4. Explain how we used the process of sampling estimate the number of brine shrimp in each beaker.
5. Is there anything we could have done that would have made our sample biased or inaccurate?