Brine shrimp are the foundation of Great Salt Lake’s ecosystem. These tiny crustaceans feed on algae and bacteria, and in turn, they feed millions of migratory birds that stop at the lake each year to rest and refuel. They’re also the basis of a multi-million-dollar industry, with their eggs harvested each fall and shipped across the world to feed fish in hatcheries and aquariums.
Brine shrimp begin life as dormant cysts—tiny, round eggs less than a millimeter wide. In the wild, these cysts are released by females in fall and float on the surface of the Great Salt Lake, surviving freezing winters, scorching summers, and even decades without water.
When spring comes and conditions improve—longer days, warmer temperatures, and fresher water from snowmelt—the cysts absorb water and begin to hatch. First, the embryo inside resumes development. Then, the outer shell cracks open, and a larva called a nauplius emerges, still wrapped in a hatching membrane.
At this early stage, the nauplius looks nothing like an adult brine shrimp. It’s mostly a head, with a single eye and a small body. It swims using its antennae and begins molting almost immediately. With each molt, it grows limbs, compound eyes, and eventually develops the segmented body of an adult.
In ideal conditions, brine shrimp can reach adulthood in as little as 8 days, though in the wild it usually takes 3 to 6 weeks. Once mature, females will either give birth to live young or release more cysts, depending on the environment.
Want to watch the lifecycle of a brine shrimp up close? Hatch them yourself!
Check out the brine shrimp terrarium of our very own Jake Dreyfous!
What you’ll need:
-A clear container or jar
-Water from Great Salt Lake OR dechlorinated tap water and non-iodized salt
-Bring shrimp eggs (can be bought from online suppliers, usually marketed as “sea monkeys”)
-A warm, well-lit spot (avoid direct, harsh sunlight)
Step-by-Step Instructions
1. Make the brine (or use lake water)
If using tap water, mix 1 tablespoon of non-iodized salt per quart of dechlorinated water. You can let tap water dechlorinate by setting it out in the open air for 48 hours.
If you get water from Great Salt Lake, you can skip the salt—it already contains what the shrimp need to hatch.
2. Add the eggs
Sprinkle in about 1/8 teaspoon of cysts. Less is more here. There are 200,000-300,000 cysts in a teaspoon.
3. Provide Light and Warmth
Brine shrimp hatch best around 80°F. Place your container in a bright, warm location like a windowsill, avoiding direct sunlight that could overheat the water.
4. Watch for Hatching
Within 15–24 hours, tiny white dots should appear—your brine shrimp have hatched!. If you plan to raise the shrimp to adults, you should transfer them immediately to a new solution made with 3-4 tbsp. salt per quart of water. If you used water from Great Salt Lake, there should be enough algae and bacteria to feed the shrimp.
These nauplii will molt several times as they grow into adults over the coming days!
5. Maintain the Habitat
Mark the water line and top off with dechlorinated water as it evaporates to keep salinity stable.
If you’re using lake water, there may be enough algae and microbes to feed the shrimp. If not, you can supplement with:
- A tiny pinch of dry yeast (once a week)
- Spirulina powder
- Or “green water” (water with cultivated algae from plant food)
Oxygen Tip:
Brine shrimp need oxygen to survive. If your jar is sealed tightly, open it daily to let in fresh air, or keep the lid loose or covered with breathable fabric like cheesecloth. You can also gently stir the water with a straw to help circulate oxygen—especially once the shrimp hatch.
Hatching Tip:
Be patient—especially if you are using water and sand from Great Salt Lake. The terrarium pictured in this post was made in December, and the brine shrimp didn’t hatch until March.
If algae grows in your terrarium, that’s okay! It means your terrarium has abundant nutrients essential for the brine shrimp to grow. Just clean off the glass with a toothbrush or paper towel. Once your terrarium is established and brine shrimp begin to flourish, your terrarium should thrive with little to no maintenance for years to come.
Happy Hatching!