Brine Shrimp, Amazing Survivors!

Engage

10 minutes

Use language arts block time for this to allow sufficient science time (30-40 minutes) the same day to set up your hatcheries.

Engage students in a “read-aloud, think-aloud” of Disappearing Lake, by Debbie Miller (youtube reading of the book).
Sitting in a circle will help make this an interactive learning experience.

During and after reading, make connections between this temporary Alaska habitat, a vernal pond where fairy shrimp hatch, and the brine shrimp we will be using for our investigation today. Brine shrimp live in extremely saline environments such as some tide pools, and the Great Salt Lake, but go into a dormant stage when conditions change temporarily.

Brine shrimp, also called “sea monkeys”, have developed a way to survive when their habitat changes. They coat their dormant eggs with a substance called trehalose that keeps them alive until they are put in water again.

Draw a big circle on board and write “brine shrimp” inside. Ask kids to brainstorm everything they know about this animal which is a shrimp. Add their knowledge to this web or bubble map. You may want to add a few pre-selected facts to this semantic map. Don’t give them too much information about the characteristics of brine shrimp at the beginning; let them discover it through their investigations. Show the package of dry shrimp, pictures, or other objects related to the investigation.

Science notebooks. Ask students to draw a picture on the cover (or first page of the section) on the topic of brine shrimp and their habitat.

Explore

40 minutes

Ask students what they think the dormant eggs may need in order to hatch (such as water, air, heat, light, salt, etc.). Ask them to write a prediction in their science notebook.

Guide them toward setting up simple experiments, individually or in small groups, connected to their prediction. These “experiments” can be as simple as observations. They do not need to do all the steps of the scientific process we might expect older students to know about, but should be able to understand the idea of a “fair test.” 

Examples:
What do they need besides water to hatch?
Do they need light in order to come alive?
Will they hatch if the temperature is cold (or hot)?

Show and explain the basic materials that are available. Organize students into small groups or pairs to plan their investigation. Regroup in 10-15 minutes and ask students to draw/write about what they plan to do in their science notebook. Circulate around groups to offer suggestions. Have students set up the first investigation and leave it to sit overnight, since it will take 24 hours or 2-3 days at 77 degrees F for the cysts to burst out of their shells. Follow the directions that come with your eggs/cysts regarding the addition of salt or baking soda concentrations. A possible rule of thumb for creating a saline environment is to add 1-1½ teaspoon of non-iodized salt per cup of water. Help children mark the full water level on their bottle or jar the first day with a permanent marker, so they can refill it to the same level as water evaporates.

Explain

10 minutes

On the day after the experiment has been set up, have students observe the changes that happened overnight and record their observations in their science notebooks with drawings and sentences. Provide time to share and discuss results.

Observe and record daily or frequently throughout this investigation. When most have hatched, move on to “Elaboration.”

Elaborate

15 minutes

At 77 degrees F the embryo should molt 15 times and reach adulthood in about 8 days.
Ask students to write the date in their science notebook, and then copy or glue in this question:
What do the brine shrimp need to grow to become adults?

Ask them to make and write predictions, then guide the class in sharing their predictions.

Ask students to select from stations of habitat choices that you have set up to test student predictions.
Some possibilities are:

• If students predict that sea monkeys need light to grow, set up a station in which one jar has full light, one has partial light, and one is dark.
• If students predict that sea monkeys need warm water, set up a station in which one jar is warmed by a heat lamp or warm water “bath,” one is room temperature, and the other is kept cool with ice or snow.

Set up combinations such as warm/light, warm/dark, cool/light, cool/dark.

Students will make daily observations and record them in their science notebooks. Model and encourage them to make drawings with labels. They will need magnifying lenses to see the shrimp.

Feeding is not necessary if tiny green thread or spots (algae) start to grow in your container. If not, you can feed only once or twice a week, a few grains of powdered yeast. This could be mixed with some salt water from the jar and fed with an eyedropper.

Evaluate

A suggested daily evaluation of the science notebook would be a checklist of required steps for each day, with points given for completion of tasks. For a self-evaluation, ask students to flag or put a sticky on their “best” drawing or writing sample.

On the final day of this unit, have students talk about, then write, “What I Learned,” through drawing and writing. Encourage them to use all the “key” terms from the investigations that you have listed on the board, or they have written in their science notebooks, and come up with new questions. Review their notebooks throughout and at the end of the investigation, guiding their learning with comments and questions.