Brine shrimp, also known as sea monkeys or artemia are a popular live food source for feeding fish and invertebrates. Their tiny nauplii hatchlings are nutritious but have very short lifespans. Just how long do brine shrimp live after hatching?
The Brine Shrimp Lifecycle
Brine shrimp have a complex lifecycle that influences their post-hatching lifespan:
- Eggs – Dormant and hardy cysts that can be stored for years
- Nauplii – Tiny freshly hatched brine shrimp larvae
- Metanauplii – Slightly larger larvae after first molt
- Juveniles – Sexually maturing adults after several molts
- Adults – Sexually reproductive brine shrimp
The nauplii stage is the focus of our lifespan question These delicate newly hatched brine shrimp require specialized care
Nauplii Lifespans
Nauplii brine shrimp are vulnerable and short-lived. Their lifespans depend on two key factors:
Water Temperature
- Colder temperatures extend lifespan
- Warmer temperatures accelerate metabolism and shorten lifespan
Water Quality
- Poor water quality stresses nauplii
- Pristine water extends lifespan
Under ideal conditions of cold, clean water, nauplii may survive 24-36 hours after hatching. However, in warm, stale water, they may only last 12-18 hours.
Why Such Short Lives?
Nauplii brine shrimp perish so quickly for several reasons:
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They lack mouthparts and cannot feed, relying on internal yolk sacs for nutrition. These limited energy reserves run out.
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Their undeveloped bodies and high surface area make them prone to osmotic stress.
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Without fully formed guts and excretory systems, they cannot process waste products that accumulate to toxic levels.
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Hatched in dense concentrations, their own waste fouls the water.
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Rapid development to the next lifecycle stage demands high metabolic rates.
Their sensitive biology and the hatching environment leads to abrupt die offs within 24 hours, often less.
Optimizing Nauplii Lifespans
While less than a day is the norm, optimal care can extend nauplii lifespan to the maximum duration:
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Hatch at cooler temperatures below 80°F if possible. This slows metabolism.
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Use greenwater made from algae cultures to oxygenate water.
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Perform 100% daily water changes to remove waste products.
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Hatch at lower densities to slow waste accumulation.
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Aerate aggressively to prevent localized low oxygen.
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Feed statically without water flow to prevent stress.
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Monitor and maintain proper salinity, pH and alkalinity.
With diligent attention to these parameters, nauplii may survive 36 hours or slightly longer after hatching. However, expect the majority to expire after 18-24 hours even in ideal conditions.
Signs Nauplii Have Reached End of Life
With such brief lifespans, most nauplii will demonstrate signs of expiration within a day of hatching:
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Limited or no swimming – Nauplii sink and settle on the bottom
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Loss of color – The orange-pink hue fades to transparency
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Clumping – Moribund nauplii congregate in clusters
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Rigidity – Dead nauplii appear static and locked in position
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Tissue degradation – Form loses integrity and disintegrates
Once these symptoms arise, nauplii have just hours left before death. Remove any uneaten live and dead nauplii promptly.
Daily Hatching is Best Practice
Given their fleeting lifespans, most aquarists find hatching fresh nauplii daily is essential. After 18-24 hours, nutritional value declines as nauplii near death. Hatching small batches each day provides optimal quality.
For large commercial hatcheries or public aquariums, techniques like greenwater, lower densities and cold temperatures can extend lifespans to 2-3 days. But for hobbyists, daily hatching is recommended.
Harvesting and Use Within Time Limit
When culturing brine shrimp, harvest hatchlings within 12-18 hours, while still vigorous and nutritious. Rinse well and feed immediately. Completely drain and replace water at least twice a day.
Never keep nauplii longer than 24-36 hours. By this point, even under the best conditions, most will be dead or dying.
Benefits of Freshly Hatched Nauplii
Despite their ephemeral existence, brine shrimp nauplii remain a top live food thanks to benefits like:
- High protein and lipid content for growth and development
- Small size for feeding fry or small species
- Stimulate natural feeding behaviors and activity
- Soft bodies are easy for most species to digest
- Nutrients differ from dried foods
- Availability and cost compared to alternatives like rotifers
By hatching frequently in small batches and feeding promptly, aquarists can take advantage of their merits while avoiding deterioration issues.
Alternatives to Live Nauplii
While live hatchlings are ideal, alternatives exist to avoid the chore of daily hatching:
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Decapsulated brine shrimp eggs – More shelf stable and easily digested
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Refrigerated nauplii – Pre-hatched and stored chilled to arrest development
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Frozen nauplii – Flash frozen right after hatching to preserve quality
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Brine shrimp flakes – Dried and processed into foods for longer shelf life
For hobbyists seeking convenience, these options provide nutritious brine shrimp without the demanding live cultures.
Maximizing the Brief Lifespan Window
Brine shrimp nauplii rank among the shortest-lived of common feeder species. But their tiny size, nutritional value and ease of culture ensure their enduring popularity. By understanding their limitations, aquarists can maximize the 1-2 day window after hatching to take full advantage of their benefits for raising fish and invertebrates.
Instructions for Hatching Brine Shrimp
This page has the best and easiest-to-follow brine shrimp hatching instructions on the web. You can use a Hatchery Dish or a regular cone-shaped container (Imhoff cone or inverted bottle) to hatch the eggs.
Before we begin, you need to start with viable, properly stored eggs. All brine shrimp eggs need to be stored as follows:
- in a tightly sealed container;
- free from moisture; and
- in a cool environment at or below 40°F. (Refrigeration is ideal for short term storage, i. e. , less than three to four weeks. To store eggs for a long time, they should be kept at or below freezing. ) .
When you get your eggs, we suggest dividing them into two groups: one should be kept in the fridge in a container with a tight lid for three to four weeks, and the other should be kept in the freezer in the same container with a tight lid for longer. Keep in mind that freezing can lower metabolic activity and delay hatch-out. We suggest taking the egg out of the freezer one day before you want to use it so that the embryos have time to get used to the temperature.
The above storage guidelines apply to all brine shrimp eggs, whether in opened or unopened tins.
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If you want to get the best results from conical hatching containers like our 2-Liter standing cone, an Imhoff cone, or an upside-down soda bottle, follow these steps:
- For most situations, a 25 parts per thousand (ppt) salt solution is best when making your hatching solution. This equates to around 1. 018 specific gravity as measured with a hydrometer. If you don’t have a hydrometer, you can get this salinity by mixing about 1 and a half tablespoons of salt with one quart (about a liter) of water. Be sure to use non iodized salt.
- pH: Proper pH can be important in hatching brine shrimp. A starting pH of 8. 0 or higher is recommended. Some places have water with a pH below 7. To those places, you can add 1/2 teaspoon of Epson salt or magnesium sulfate per quart of hatching solution.
- Temperature: The best water temperature for a full hatch that lasts 24 hours is between 26 and 28°C (80 to 82°F). Lower temperatures will cause hatching to take longer and not work as well. Do not exceed 86° (30°C). Do not put an immersion heater right into the container where the eggs are hatching! An immersion bath is better for keeping the temperatures stable. If the conditions are right, an incandescent bulb placed above the hatching cone can also provide enough heat.
- Light: During the first few hours of incubation, the embryo needs to be lit up in order to start the hatching process. Keeping a light on during the whole incubation period is suggested for the best hatch results and, as we already said, to keep the temperature stable.
- Continuous aeration is needed to keep cysts in suspension and make sure there is enough oxygen for the cysts to hatch. During the incubation, there should be at least 3 parts per million of dissolved oxygen. Strong air flow shouldn’t hurt or damage the cysts or nauplii of brine shrimp. A rigid air tube is the best way to get air to the bottom of the cone and keep eggs that haven’t hatched from falling to the bottom. We do not recommend an airstone.
- For the best hatching rates, stocking density should be 1 gram per liter or quart, which is about 1/2 teaspoon of cysts per quart (or liter). A higher stocking density will lower the number of eggs that hatch and make it harder to tell the difference between hatched nauplii and eggs that haven’t hatched yet.
- Hatching Cone: Flat-bottom hatching vessels should be avoided. Containers with cone or “V” bottoms work best to keep the cysts floating while they hatch. When not in use, make sure to wash the hatching cone well with a mild chlorine solution, rinse it, and let it dry naturally. Avoid soap. Soap will leave a thin film that will foam when the eggs hatch and leave the cysts floating above the water.
- Incubation Period: Generally, the optimum incubation time is 24 hours. If an egg has been stored properly for more than two to three months, it may need more time to hatch—up to thirty to sixty hours. Oftentimes, eggs will hatch in as few as 18 hours. If you want smaller nauplii (Instar I), you should wait 18 hours before harvesting them. After that time, you can get Instar I (first stage) nauplii before they change into Instar II.
Brine shrimp egg is sometimes very buoyant. To get the most eggs to hatch, it can help to swirl the water in the hatching container with your finger a few times during the first four to six hours of incubation. This will knock down any eggs that are sitting on the side of the container above the water line. After about 6 hours, the eggs are usually well-hydrated and will stay in the water column.
The following steps will achieve optimum brine shrimp hatch rates.
- Set up: Put a hatching cone or other similar-shaped container in a well-lit area. The cone should be partly see-through so that it is easy to harvest and let light through.
- To add water, fill the cone with water and set the salinity to 25 ppt. Optimum hatching temperature is 82°F (28°C).
- Add Cysts: Put in 1 gram of cysts per liter.
- Aerate: Provide adequate aeration to keep cysts in suspension.
- Hatch: Eggs should hatch in 18 to 36 hours, depending on the temperature of the water.
- Harvest: Once the brine shrimp have hatched, turn off the oxygen and wait a few minutes for the shells and baby brine shrimp (called nauplii) to separate. New nauplii will either fall to the bottom of the cone or move toward a light source. The shells will float to the top. If there is a valve on the bottom of the cone, the nauplii can be gently drained through it or sucked out of the bottom with a length of air tubing.
- To sum up, the warm temperatures during incubation and the chemicals in the hatching medium make it perfect for a bacteria bloom. Before you feed the baby brine shrimp to your fish, you should rinse them in clean fresh or salt water through a fine mesh net or sieve.
- Clean Equipment: Tanks and equipment used to hatch brine shrimp should be cleaned and sanitized regularly.
Flat-bottom hatching vessels should be avoided. Cone or “V” bottomed containers are best to insure that the cysts remain in suspension during hatching. When not in use, make sure to wash the hatching cone well with a mild chlorine solution, rinse it, and let it dry naturally. Avoid soap. Soap will leave a thin film that will foam when the eggs hatch and leave the cysts floating above the water.
Generally, the optimum incubation time is 24 hours. If an egg has been stored properly for more than two to three months, it may need more time to hatch—up to thirty to sixty hours. Oftentimes, eggs will hatch in as few as 18 hours. If you want smaller nauplii (Instar I), you should wait 18 hours before harvesting them. After that time, you can get Instar I (first stage) nauplii before they change into Instar II.
Hatching Baby Brine Shrimp is EASIER Than You Think!
How long do brine shrimp live?
Brine shrimp, also known as Artemia, have a very short lifespan of up to six months. They are very active creatures that spend their time filtering food from the water and breeding.
How to hatch brine shrimp eggs?
To hatch brine shrimp eggs, first prepare a suitable hatching container. A common choice is a small glass or plastic container with a lid. Thoroughly clean and free the container from any contaminants before adding the brine shrimp eggs.
How long do baby brine shrimp eggs last?
Baby Brine Shrimp eggs have a shelf life of about 2 years when properly stored. They remain inactive until introduced to salt and water, at which point they hatch into live brine shrimp.
How do you keep brine shrimp from hatching?
Use a length of air hose to easily siphon the live brine to your grow out container. This separates the brine shrimp from the egg casing that decay and waste left from hatching. It gives the brine shrimp clean water and clean container to grow in and be fed in. HOW TO: DIY brine shrimp hatchery | Simple & Easy, yet Very Efficient! (Artemia Cysts)