Brine Shrimp Life Cycle, Size & DIY Hatchery Guide

Brine shrimp (Artemia salina) are the backbone of the aquarium hobby. Whether you are breeding fish, raising dwarf shrimp, or just want to fatten up your community tank, freshly hatched nauplii are the best live food you can use. They are packed with protein, trigger natural hunting instincts, and cost pennies to produce. Here is exactly how they grow, how big they get, and how to build a DIY hatchery that actually works.

Brine Shrimp Quick Facts: Life Cycle, Size & Lifespan

Description of the Brine Shrimp

Brine Shrimp (Artemia Salina) are relatively tiny organisms commonly found in isolated habitats, namely salt lakes and water bodies like the renowned Great Salt Lake (Utah), Rocky Coast south of San Francisco, and the Caspian sea.

Other species can be equally found in many other water bodies with high or moderate salt content.

Appearance of the Brine Shrimp

Quick overview: Adults reach 8–15 mm, pale white to pink or transparent. They have a segmented body with leaf‑like swimming legs (phyllopodia) that beat in a regular rhythm.

Detailed anatomy: еhe body is divided into head, thorax, and abdomen. 

• Head: One pretomial and five metameric segments bearing compound eyes on flexible stalks, mouthparts, and antennae.
• Thorax: Eleven segments, each with a pair of swimming legs (phyllopodia).
• Abdomen: Eight segments; the first two are the genital segments.

A thin, flexible chitin exoskeleton covers the body. Muscles attach internally, and molting allows the shrimp to shed its old exoskeleton and form a new, stronger one.

Habitat and Ecology

Where Brine shrimp live:

Isolated salt lakes (e.g., Great Salt Lake), coastal salterns, brackish water (2.9–3.5%) up to hypersaline (25–35%). Can tolerate up to 50% (near saturation). Never in the open ocean — too many predators.

Global distribution:

~500 natural salt lakes and man‑made salterns in tropical and temperate zones.

Why high salinity? 

Brine shrimp use salt as a shield. Predators and competitors can’t survive there. They can tolerate up to a 50% salt concentration which is almost saturated.

Key adaptations (in short):

• Efficient osmoregulation (gills absorb/excrete ions).
• Respiratory pigments for low oxygen at high salinity.
• Can produce dormant cysts within days if conditions worsen.

Behaviour of the Brine Shrimp

• Swimming upside down (phototaxis)

Brine shrimp are positively phototactic — they swim toward light. In nature, they point their appendages upward toward the sun. They rise during the day and sink at night.

• How they move

The same phyllopodia that feed them also propel them. They beat rhythmically to swim toward food, ignoring most of the environment.

• How they feed

Two methods: 

1. Filter‑feeding: fine spines on legs trap particles as they swim.
2. Grazing: scrape algae off rocks and bottom mud with fast leg movements.

Captured food moves forward along a central food groove to the mouthparts.

• What they eat

Yeast, bacteria, wheat flour, soybean powder, egg yolk, and algae.

• Adaptations for salt (summary)

Gills absorb and excrete ions as needed.

Life Cycle (from cyst to adult)

Two ways to reproduce 

1. Sexual. Brine Shrimp reproduces when a male clamps on a female with his large second antennae and fertilizes her eggs, thereby leading to production of diploid zygotes. Afterwards, the female lays the eggs in a brood sac in the water.
2. Parthenogesis (common). Reproduction without fertilization is also common among brine shrimp where a female lays unfertilised eggs that will develop into female offsprings.

Cysts: the dormant stage 

If conditions aren’t right (temp <86°F (30°C), water scarce, too salty), fertilized eggs are encased in a thick shell as cysts. They can stay dry for years. 

Important: Cysts won’t hatch if SG > 1.04 or temperature <50°F (10°C).

Hatching process 

1. Studies show that prior to hydration, the cysts of Artemia salina are cup-shaped with a diameter of approximately 0.18 mm. Upon immersion in sea water, the cysts slightly increase in diameter to 0.19 mm and assume a spherical shape.  

2. Outer membrane cracks after ~20 hours. 

3. Embryo hangs underneath, completes development into nauplius. 

4. Hatching membrane ruptures → free‑swimming nauplius. 

Growth to adult 

• 15 molts (instars) 
• Sexual maturity in 18–21 days (according to the researches) 
• Adults produce ~300 nauplii every 4 days

Brine Shrimp Larval Stages (Instars)

1st stage (nauplius) 

• Brownish‑orange color, red nauplius eye.
• Three pairs of appendages: antennae (sensory), second antennae (locomotion + filter‑feeding), mandibles (food intake).
• Ventral side covered by labrum.
• Digestive tract not yet connected → feeds on yolk sac.

→ Nutritional value drops as yolk is consumed.

2nd stage (8–12 hours later) 

Molts → digestive tract opens. Starts filtering algae and bacteria. 
Important: If not fed, larvae die during 3rd or 4th instar.

Later stages (up to 15 molts) 

• Paired lobular appendages appear → become thoracopods.
• Lateral compound eyes develop.

From 10th stage onward 

• Males: antennae grow into hooked graspers.
• Females: antennae degenerate into sensory appendages.
• Thoracopods differentiate into three functional parts:

* Telopodites & endopodites (locomotion + filter‑feeding) 
* Membranous exopodites (gills for respiration)

Fun fact: Each stage is separated by a molt. They can produce 300 nauplii every 4 days.

Brine Shrimp, Water Parameters, and Salt

It is important to ensure that the water in the hatching mechanism can actually facilitate proper hatching of the brine shrimp eggs.

Maintain the following water parameters:

• Water temperature: 25 to 27.5°C (80 – 82°F)
• pH: Not lower than 8
• Stocking Density: 1 gram of brine shrimp eggs per 1 litre of water.
• Salt: Instant Oceans, Epsom salt, Aquarium rock salt, even Kosher salt.

What Salt to Use?

You can use some Instant Oceans, Epsom salt or aquarium rock salt and baking soda to get the right salt concentration needed in the hatchery, anything slightly above the average salt concentration (25ppt = SG- 1.018) is good.

Note: Actually, there is no need to use Instant Oceans when you can have almost the same result with the cheaper ones. The point is that Brine shrimp will not live long enough to feel the difference anyway.
Calculation Tip: If you do not have hydrometer, you need to add approximately 2 tablespoons of noniodized salt in one quart (roughly, one liter) of water. The exact amount of salt is not critical.

Hatching Brine Shrimp. DIY Setup

One of the best food for fishes, shrimp, crabs and other aquatic animals is definitely freshly hatched brine shrimp. These are very rich in protein and fatty acids, which is quite essential in promoting growth and development. Here, I am going to provide you with a detailed and comprehensive guide on how you can hatch and grow fresh brine shrimp for your home aquarium.

You can easily opt for a DIY hatching setup using a funnel-shaped container considering how expensive hatcheries can be. Although they are not very convenient and effective as brine shrimp hatchery kit, or hatcheries available at the pet store but they are easy to set up and gets the job done.

For DIY setup, you are going to need:

• A large soft drink plastic container (bottle).
• Air pump with airline tubing and rigid tubing.
• Non-Iodized Salt (Aquarium salt or Epsom salt or Instant Ocean Sea Salt, etc.).
• Baking soda.
• Brine shrimp eggs.
• Light source (for example, Desk lamp with Incandescent or halogen light bulb that produces heat).

Basic DIY Setup

In a nutshell: You need a 2L bottle, air pump, salt, baking soda, and brine shrimp eggs. Total setup time: 5–10 minutes. Hatching takes 24–36 hours. Keep temperature at 77–86°F (25–30°C), salinity ~25 ppt (2 tbsp salt per liter), and strong aeration.

1. Prepare the bottle 

Take a 1.5–2 liter bottle and cut 1/3 off the bottom. 
→ Why: The top part will become the cone, the bottom part acts as a stable base. 

2. Stabilize the base 

Fill the bottom part with gravel or sand. 
→ Why: Prevents the hatchery from tipping over when full of water.

3. Insert the airline 

Place rigid airline tubing so the opening touches the very bottom center. 
→ Why: If the airline is off‑center, some cysts won’t get enough aeration and will stay stuck on the bottom. 

4. Control the airflow 

Add a gang valve. 
→ Why: You need strong bubbles to keep all cysts suspended, but not so strong that water bubbles over the top.

5. Fill with dechlorinated water 

Use aged water (chlorine evaporates in 24 hours). 
→ Why: Chloramines in hard water can prevent hatching or reduce success rates.

6. Add salt 

Use non‑iodized salt (aquarium, Epsom, or kosher). Approx 2 tbsp per liter. 
→ Why: Brine shrimp need salinity above 25 ppt (SG ~1.018) but below 1.04. Exact amount is not critical.

 7. Add eggs 

1 teaspoon of healthy cysts per liter of water. 
→ Why: Higher density reduces hatch rate and oxygen availability.

8. Cover the top 

Use plastic wrap or a loose lid. 
→ Why: Prevents spray, keeps water warm, reduces evaporation.

1. Take a large (1.5 – 2 liters) bottle and cut 1/3 of the bottle from the bottom.
2. Fill the bottom part with something heavy (gravel, sand, etc), to make it more stable.
3. Reverse the top part and place it into the bottom part of the bottle.
4. Add an airline for filtration tight to the bottom at the center.

Harvesting Brine shrimp

• When the Brine shrimp hatch, the water will change color to orange.
• Disconnect the airline fixed to the end of the pump and move the light source to the very bottom of the container. This works because brine shrimp nauplii are positively phototactic — they swim toward light.

Tip: If the lamp is too big/bright and you cannot manipulate the light – just cover the top half of the bottle.

• Wait for 5 to 10 minutes for the baby brine shrimp to swim to the bottom of the container. The shells of hatched eggs will float, unhatched eggs will settle to the bottom, and the young shrimp (nauplii) concentrate in the light.
• Using the airline, you are advised to siphon only the orange-colored baby brine shrimp from the bottom of the cone into your designated shrimp net, which should suspend in a glass of water to prevent damage to the nauplii. However, do not siphon hatched shells, which tend to float at the surface.
• Important: Quickly and gently rinse the baby brine shrimp with clean tap water at your sink. You can use a coffee filter to rinse it. We do that to avoid adding any unwanted salinity to our tanks. This is especially important if you have a freshwater tank.
• Feed each aquarium with the freshly hatched baby shrimp. Do not deposit too much brine shrimp all at once rather feed as much as your fish can consume in a couple of hours. Do not overfeed!
• Tip: You can enrich Brine shrimp with astaxanthin to improve the coloration of your fish, shrimp, or crabs.

You can read more about it in my article “How to Enhance Shrimp Color?”.

Reusing the Hatching Water

• We can safely reuse the hatching water 2 – 3 times more (but … why!).
• Remove eggshells.
• Top up with freshwater, if you forgot to cover the container and some of the water evaporated.

Cleaning

Clean up the hatching equipment to be used for the next hatching process.

• Scrub the container with a sponge and properly diluted household bleach
• Rinse it thoroughly to remove all dirt.
• Tightly seal the egg container to prevent moist air from coming in contact with the egg cysts.
• Store in the refrigerator until the next usage.

Brine Shrimp and Aquaculture

The nauplii of the brine shrimp is commonly used in the culture of fishes, crabs, and when breeding dwarf shrimp (Neocaridina, Caridina, etc.), and other freshwater organisms. The incubation of brine shrimp cysts in the hatchery results in the release of nauplii that can directly be fed to the larvae of a variety of freshwater organisms.

Note: Dwarf shrimp are scavengers and prefer dead organic matter. So, frozen brine shrimp is your choice.

Brine shrimp are known to have high nutritional value. They have high protein content and are rich in amino acids. They make a bigger prey thus resulting in a better energy balance per hunting effort for predating fishes or shrimp larvae that can ingest them. Brine shrimp is very popular as live feed for ornamental fish in the tropical aquarium industry, it can be frozen, freeze-dried, or acid preserved for later use or made into flakes.

If you are into aquaculture and need the least labour-intensive live feed for your baby fishes then the brine shrimp is your best bet. They are nutritious, easy to obtain, hatch, and harvest; your fishes will love them totally! 

How to Grow Brine Shrimp to Adults (Optional)

If you need adult brine shrimp (e.g., for larger fish or breeding):

1. Tank setup: 5–10 gallon, gentle aeration, no filter (they will be sucked in).
2. Water parameters: Same salinity (25–35 ppt), temperature 77–86°F (25–30°C).
3. Feeding after nauplii stage (day 2 onwards):

• Baker’s yeast (tiny pinch per 1000 nauplii, twice daily)
• Spirulina powder or liquid fry food
• Avoid overfeeding — water fouls fast.

 Water changes: 20% every 2–3 days, siphoning debris from bottom.

Growth timeline: 

• Day 1–2: nauplii (yolk sac)
• Day 3–8: instar stages (feeding required)
• Day 18–21: sexual maturity (8–15 mm)

Note: Adults will breed and produce new cysts. You can then start the cycle again.

For other live food options, see cyclops profile or tubifex worms.

How does brine shrimp compare to other live foods?

FAQ about brine shrimp hatching

Can I refrigerate brine shrimp?

Yes. They can be refrigerated (not frozen) for several days.

Why are my brine shrimp dying?

They could be overcrowded. If so, divide the culture. There could be insufficient aeration, or you could be using a wooden air stone or other air stone that produces a fine “mist” of bubbles. These small bubbles can clog the shrimp’s feeding system and starve them.

Do brine shrimp need light to hatch?

Actually, brine shrimp do not need light to hatch. We use light to heat the water and manipulate its movement. Some people believe that light can also trigger the hatching mechanism. Personally, I do not think that it plays such a big role.

Do brine shrimp need an air pump?

Yes, brine shrimp need an air pump. We use it to keep the water oxygenated (so brine shrimp will not suffocate). In addition, flowing water prevents them from sticking to the sides of the container.

Do brine shrimp need a heater?

Brine shrimp need a warm temperature. They do not care about the source of the heat. It can be a heater, a table lamp, or anything else.

Can fish eat brine shrimp eggs?

No, fish cannot eat eggs. The eggs cannot be used as fish food because fish cannot digest the tough shells.

Why Won’t My Brine Shrimp Hatch?

There can be many reasons for that, for example:

• The brine shrimp eggs are too old.
• The temperature is too high or low.
• Too low pH.
• Too high salinity level. As I have already said before the eggs will not hatch if SG is more than 1.09.
• They need more time. Sometimes after the freezer, it can take them 36-48 hours to hatch instead of 24 hours.

How can I store Artemia Eggs?

The brine shrimp eggs will remain viable (alive) for at least 10 years when stored in:

• A dry and tightly sealed container.
• A fairly cool place at or below 50°F for a few weeks. (For longer-term storage, put your brine eggs in a freezer).

Nonetheless, keep in mind that old eggs have a greatly reduced hatch rate.

Can brine shrimp live in freshwater?

No. Both nauplii and adults will die within a few hours in freshwater. Their osmoregulatory system cannot handle the sudden influx of water. 

What to do: Always rinse harvested nauplii with freshwater before feeding to freshwater fish. Never release brine shrimp directly into a freshwater tank.

Related article:

• 15+ Live Food Options for Aquarium Fish