Introduction How to raise baby brine shrimp for feeding to jellyfish

Live food is one of the best ways to keep captive jellyfish well fed and able to grow. Baby brine shrimp (i.e. Artemia) are one of the most common and easiest ways to feed the jellyfish live food. Different species of Artemia have differing nutritional values to jellyfish, enriching them ensures that they are able to nourish your jellies. This guide is based upon a year of breeding along with reading and advice from several sources, including books and commercial suppliers. Feedback, corrections, or general correspondance are welcome and appreciated. This guide was last updated on Dec 12th, 2019.




Tip: Green colored boxes are good habits I found helpful in ensuring my yield of Artemia nauplii stayed large and alive.
Purchase: Blue colored boxes are tests or equipment purchases that I found particularly helpful.
Caution: Orange colored boxes are cautionary warnings about things that may reduce your Artemia yields.
Important: Red colored boxes are strong warnings about things that may ruin your Artemia batch or make it worthless to the jellies.

Glossary Some commonly used terms and acronyms

Artemia
The family of crustaceans that are commonly used in aquaculture to feed a variety of pets and animals. Artemia live in extremely salty water, and their eggs are extremely hardy, able to survive for years dry.1, 2, 3, 4 The durability of the eggs makes them ideal for storage and breeding. The high salt content of their natural environment prevents the introduction of unwanted pests.
HUFA
Highly Unsaturated Fatty Acid. Believed to be the most important nutritional aspect of food for marine life. HUFAs are a category of organic molecules that include several specific types, including dososahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and docosapentaenoic acid (DPA).6
Nauplius (nauplii pl.)
The juvenile larvae stage of a crustacean. For jellyfish feeding, the nauplius is the only useful form of the Artemia due to the lack of a hard, undigestible shell.
SELCO
A commercial product developed by INVE Aquaculture in Belgium, stands for "Self Emulsifying Lipid Concentrate".7 It is essentially a thick paste made entirely out of lipids, fatty acids, and other organic compounds nutritious to marine life. Many stores in the USA import and resell for hobbyists. Be aware that INVE Aquaculture makes a large variety of SELCO types, and they are different from one another.

Equipment What you will need and how to build it or buy it

Hatcheries

Brine shrimp eggs need oxygen, current, light, and heat to hatch.1, 2, 3 The eggs cannot hold still in the water, or they will not hatch.1, 2, 3, 4 Thus, most hatcheries are inverted, rounded cones, allowing the user to insert air tubing to the bottom, and use the bubbles to push the eggs around in the water and supply oxygen. Some hatcheries have spigots at the bottom for easy drainage, others (such as DIY ones) have no valve; the nauplii must be siphoned out using a baster or tube. For convenience, consider buying 2-3 hatcheries, allowing you to easily transfer the harvest into a fresh hatchery for further enriching/feeding/molting without having to rinse out the old hatchery in a hurry.

Purchase: This pre-made hatchery designed by Florida Aqua Farms Inc. has several subtle features to make hatching and raising more convenient. The hatchery comes with its own sturdy PVC stand to prevent accidental spillage. In addition, it has a valve at the bottom for easy harvesting and draining. It also comes with rigid air tubing, silicon tubing, a two-way air valve to adjust air flow, and a sterile collection cup. Lastly, the bottom of the cone has a slight slope so that dead eggs, and nauplii capsules can drift to the bottom and not be drained out, saving you minutes with the sieve at harvest time. It currently sells on their site for $33.95. A different (i.e. will not build this specific hatchery) do-it-yourself kit is also available for $8.95.

Large Hatchery Cone with stand

Air pump

The air pump used for the aeration generally needs to be more powerful than expected. Aside from power, the only other consideration is noise, depending on where you place your equipment. I find a 60-gallon pump to be sufficient to move two different hatcheries with up to 2 liters of water each. A 10-gallon pump is sufficient to move 1 to 1.5 liters of water and keep the eggs suspended.

Purchase: The Tetra Whisper 60 pump is a quiet pump that also includes a free two-way valve to adjust air current as necessary (useful if you did not purchase a pre-built hatchery that came with its own two-way air valve). The 60-gallon model is sufficiently powerful to move two hatcheries with 2 liters of water each and keep the eggs suspended in the water column.

Tetra Whisper 60-gallon air pump at Amazon

Infrared thermometer (optional)

Infrared thermometers read the temperature of objects by measuring the amount of infrared radiation they emit. This has the advantage of not being physically immersed in the hatching water, saving on cleaning time.

Purchase: Any infrared thermometer will do, many are on sale at Amazon or Woot.com. This thermometer is just $17 and it has a 2% margin of error.

Etekcity Infrared Thermometer at Amazon

5.25%-6.00% bleach (optional)

In general, it is not recommended to wash hatching equipment with soap, as it will leave a film that makes the eggs and nauplii stick and suffocate.4 Bleach is also a much more convenient way to sterilize the hatching equipment because you can simply soak the equipment overnight and then just dump and rinse several times. The recommended amount of bleach is to put in about 1 part of 5.25%-6.00% bleach solution per 100 parts water.5

Tip: In practice, I put in 1 capful of bleach per liter of water. One gallon is 3.785 liters, or approximately 4 liters per gallon.

Light

Most brine shrimp hatchery setups combine light and heat, by using an incandescent bulb. A single 100 watt incandescent bulb placed in a lamp approximately 6 inches from the hatchery is enough to heat the eggs to the desired 80-82 degrees farenheit (distance will depend on your own local temperature). Lower wattage bulbs are also appropriate if placed slightly closer. If you do not have a desk lamp, Home Depot or Amazon sell incandescent work lamps. Make sure to think about how you will place the lamp, as some only have hooks and cannot be placed on a flat surface (i.e. you may need to buy clamps).

Purchase: I do not own or use this exact lamp personally, but I have one very similar. This one does not have a flat base, and must either be clamped into place, or hung using the hook. My model is also rated for 75 watts, but I have been using a 100 watt bulb with no problems.

Designers Edge E-237 work light on Amazon

Sieve or net

If your hatchery has a drainage valve, you can use a sieve or net of the appropriate fineness to catch the nauplii from the draining water. Otherwise, a turkey baster works just fine to siphon out the nauplii once they congregate towards a light source. I recommend buying both a sieve box online, and finding an Artemia net at a local fish store, as both have uses during harvesting.

Purchase: This Artemia nauplii sieve is well constructed and has survived countless cycles of saltwater soaking, rinsing, and drying. It is available at Brine Shrimp Direct for $5.95.

Artemia Hatching Sieve at Brine Shrimp Direct

Buckets of salt-water

I highly recommend buying at least two 5-gallon buckets to store pre-mixed salt-water for use in hatching. You can either use one bucket to mix and another to store, or you can use both buckets to hold different salinities. I find it convenient to hatch in 25 ppt saltwater, but to feed/enrich/store in 32-35 ppt saltwater matching my jellyfish tank. That way I can squirt harvested nauplii directly into the tank. You can find 5-gallon buckets at any local Home Depot store for about $2.78 a piece.

Purchase: While you can order online, it may be cheaper and easier to simply pick these up at a local store along with the incandescent work lamp and cleaning bleach.

5-gallon Orange Homer Bucket at Home Depot

Mini ice-cube trays

It is extremely difficult to keep nauplii alive and sanitary for feeding for more than a day. Freezing them is the most convenient way to preserve their nutritional value without contaminating your jelly tanks. The ice-cube tray allows for food to be conveniently pre-measured to ensure proper nutrition and avoid overfeeding.

Purchase: These mini ice-cube trays can be flexed to shake loose the cubes once they are frozen. Each cube is conveniently sized for 2mL or enough to feed most jelly tanks for an entire day.

Pack of 2 mini ice-cube trays at Amazon

Decapsulated brine shrimp eggs

Brine shrimp eggs typically come in two species, the more common Utah salt flats kind, and an uncommon smaller San Francisco species.4 The San Francisco species is smaller than the Utah species.3 For moon jellyfish, most owners will have full grown adult medusae who are more suited towards eating the larger Utah nauplii, although either species is perfectly nutritious when enriched. Note that most sieves are only for the Utah size nauplii.

Eggs are normally contained within a hard barrier, called a cyst. This must be removed because the jellyfish cannot digest it, and if swallowed will cause damage to the inside of the jellyfish as it works its way out. For convenience, it is highly recommended you buy decapsulated brine shrimp eggs saving you the cyst removal process (which is not covered in this guide).

Purchase: Brine Shrimp Direct sells decapsulated brine shrimp eggs stored in an inert solution for use with animals who cannot tolerate cysts (such as jellyfish or seahorses). The 100mL bottle is more than enough for several months and can be stored indefinitely in a refrigerator. If you prefer larger quantities, a 400mL bottle is also available.

100mL Shell Free E-Z Egg at Brine Shrimp Direct

SELCO

SELCO is imported from manufacturers in large gallon containers for use in industrial aquaculture. Several resellers repackage SELCO into more appropriate sized bottles.

Purchase: This SELCO is the SPRESSO variant, and not the SUPER SELCO referenced in Chad's book. This makes little difference if the enrichment dose is adjusted accordingly. It is repackaged into a smaller container for use by hobbyists. The 125mL bottle is the smallest size available, and it will last for quite a while.

125mL SELCO SPRESSO at Brine Shrimp Direct

Algae paste

A starving animal by definition does not contain much nutrition in its body. A well fed nauplii not only has the nutrition of its own body mass, but it also has the contents of its digestive tract to feed whatever consumes it. There is uncertainty over whether the nauplii simply are coated or actually eat/absorb the SELCO enrichment, but growing them out an extra day will render this moot. Thus, the algae paste becomes a useful way to ensure your time is well spent.

Purchase: These algae pastes are used to feed the nauplii, keeping them well fed and naturally nutritious with HUFA. The Nannochloropsis algae paste is glycerine free, but the mixed paste is not. The Nannochloropsis paste is suitable for storage in a refrigerator for 3 months, while the mixed paste is best stored frozen. Both come in 125mL bottles which is more than enough to handle 3 months of hatching.

125mL Nannochloropsis Algae Paste

125mL Tahitian Blend Algae Paste

Pure water source

Cleaning the nauplii to avoid contaminating your display tanks is an important step. This is most economically done using large quantities of pure freshwater, preferably using a reverse osmosis and deionization system. If you do not have access to one in your house, you may use steam distilled water from stores. It is not recommended to use tap water unless you have tested it and have verified it is free of ammonia, chloramines, and other compounds that are poisonous to marine life. If you do use tap water, I recommend performing a final rinse with some steam distilled water to eliminate any contaminants.

Hatching How to maximize the number of hatched eggs

1. Fill hatchery with saltwater

The saltwater used should be relatively low salinity, approximately 15-25 ppt.4 pH of the water should be at 8.0-8.5.1, 2 The amount of water placed in the hatchery should be based upon how powerful of an air pump is available. A 10-gallon air pump can move 1 to 1.5 liters of water, whereas a 40-gallon pump can easily keep 2 liters of water moving.

Tip: Artemia eggs hatch by soaking up water, and then using up their energy reserves to generate glycerol.1 When sufficient osmotic pressure is built up, the egg bursts open and the nauplii emerges.1 The lower the salinity of the hatching water, the less glycerol that needs to be produced to burst open the egg, thus leaving the nauplii with the most energy reserves and the most nutritional value.1 Once the nauplii are hatched, all further work should be done with saltwater that matches your tank. This is what the nauplii expect in the wild but also conveniently lets you inject the nauplii into your tank whenever you want, without diluting your tank salinity.

2. Insert air tubing and turn on pump

The air pump should be kept at maximum power for two reasons: to keep the eggs in circulation and to oxygenate the water. Without movement, the eggs will not hatch.3, 4 The most important factor that drives hatch rates is the circulation of the eggs, combined with water quality.3 In addition, hatch rates are best maintained if oxygen levels are kept above the 5.0 ppm level (saltwater saturates at approximately 8 ppm).1, 2 A strong air pump will ensure your hatchery stays at the 8 ppm level.

Tip: Insert the rigid air tubing into the drainage hole of your hatchery if it has one. This will prevent eggs from settling down in the valve and not hatching.
Tip: The vibration of sufficient aeration will generate a loud buzzing noise. You can dampen and almost eliminate this noise by placing the hatcheries on top of a towel or rubber mat. Further noise reduction can be achieved by putting the air pump on a towel or rubber mat.

3. Add brine shrimp eggs

Measure out decapsulated brine shrimp eggs and insert them into the hatchery with the saltwater. For starting batches, I recommend following the directions of the decapsulated E-Z egg and doing 2g (or one provided spoon) of eggs per liter of water.

Caution: Putting too many eggs in the water will prevent some from hatching. I've had success doing up to 3 spoons or 3g equivalent in 2 liters of water. The large hatcheries recommended above can in theory take up to 11g equivalent of decapsulated eggs using 2L of water.3 For practical purposes, it is not recommended to try anything above 2g equivalent per liter of hatching water.1, 2 If your eggs are settling to the bottom, disturb the water occasionally with a turkey baster every hour. The eggs may just need to hydrate in order to stay in the water column. If they continue to settle, then your air pump is not powerful enough.

4. Place heating light

Place and turn on your light. Brine shrimp require about 2000 lux (i.e. daylight) to hatch.1, 2, 3 Wait 1 hour, and then measure the temperature with a thermometer. The ideal hatching temperature for the Utah strain of Artemia is 77-82 degrees farenheit.1, 2, 3, 4 Lower temperatures in the low to mid 70's will still hatch all the eggs, but will require more time.

Tip: Once you have found a good spot for your lamp and the temperature falls in the range desired, try to mark or remember it in some way. I have lost count how many times I had to setup my lamp after bumping into it.
Important: Higher temperatures are problematic, too high and you will kill the eggs. If your temperature stays above 90 degrees farenheit, your eggs will not hatch, and may become inert (i.e. dead).2 I've had eggs go above 90 for a short while and still hatch perfectly, but it's not a certain thing. I personally tend to shoot for a lower temperature of 76-80 degrees farenheit so that an unexpected surge in temperature will not kill the eggs. This still gives nearly 100% hatch rates in 24 hours and will reduce accidental loss of a batch.

5. Wait

Wait 12-24 hours. Depending on salinity, your eggs will probably fully hatch in 12-18 hours, sometimes up to 24 hours after hydration. Lower salinities will result in faster hatching times.1 To check on your hatching, dial your two-way air valve closed and let the water settle. Once the water stills you should easily see movement of the hatched nauplii. Once the nauplii hatch, remove the air tubing and let the water settle.

6. Harvest nauplii

If your hatchery has a drainage valve, you can drain the hatchery into your sieve and use a large bowl to catch the water. Otherwise, wait for the nauplii to settle at the bottom or towards a light, and siphon them out with a turkey baster one portion at a time.

Tip: Nauplii are positively phototactic, and will swim towards light.1, 3 You can concentrate the nauplii in a particular region by keeping a light shining and removing other light sources in the room. This is typically done to concentrate them at the bottom near a drainage spigot.
Tip: If you are draining the nauplii out of a valve and into a sieve, it helps if you have the receiving container be partially full of water. This makes the nauplii land in water rather than hitting the sieve mesh straight on. If you don't, some of your nauplii will be damaged and simply sink to the bottom during feeding.

7. Rinse nauplii

Once the nauplii are out of the hatchery, they will be in a concentrated liquid mass along with a large quantity of egg capsules, hatching membranes, and other debris. The goal of the rinse process is to remove the debris to avoid polluting your animal tanks at feeding time. In addition, the hatching water is full of metabolites and other leftovers from the eggs and will be laden with bacteria.3, 5

Use pure water to gently rinse the nauplii out of the sieve/net and into a large (1-2L) clean container. Fill that container up with more pure freshwater. The nauplii will concentrate towards the bottom of the container due to the fresh water, leaving large amounts of debris floating up top.

Use a turkey baster to siphon out the debris laden water at the top. Don't worry about a few nauplii being caught in the water. When the water level gets low and close to the nauplii concentration at the bottom of the container, refill with pure water and repeat.

Periodically put the entire container through the sieve to remove smaller particles, and then repeat above to get more debris out. The entire process should take around 1-2 hours. Once the water is clear, and you are satisfied you have most of the debris, you may feed some of the nauplii to your jellyfish and enrich the rest.

Tip: Artemia can survive for up to 5 hours in pure freshwater without permanent damage.3 You may take your time sorting out the nauplii from the debris, so long as you regularly disturb the water every 15 minutes to ensure they get sufficient oxygen.
Tip: Using pure reverse osmosis/deionized water to rinse your nauplii is preferable because of two factors. The nauplii will concentrate at the bottom of the container instinctually seeking higher salinity water. This allows for easy separation of nauplii from debris. The other benefit is the fresh water will kill some bacteria due to osmotic shock, leaving the nauplii alive and well.
Caution: When using a sieve/net, gently pour the water and try to have the receiving sieve/net partially submerged to cushion the nauplii.1, 2 Excessive force can mangle the nauplii into clumps, making them unable to swim, and simply sinking to the bottom (away from the jelly you want to feed).

Enrichment & Feeding How to make your nauplii as nutritious as possible for your jellyfish

1. Verify nauplii have a digestive tract

As a rule of thumb, nauplii grow their digestive tracts 12 hours after they hatch. In practice, this means letting the nauplii hatch for approx. 24 hours and they should be in instar II stage with digestive tracts (i.e. 12 hours to hatch, 12 hours to instar II).

2. First feed and enrich

Fill a hatchery as above, using 30-35 ppt saltwater and setup the aeration using an air pump and rigid air lines. Add the nauplii to the water, and add 1mL of algae paste and 1mL of SELCO SPRESSO (or 1 drop of SUPER SELCO) per liter of water.5 Let this sit for 12 hours, allowing the nauplii to feed and ingest the SELCO.

Tip: It is almost exactly 20 drops to the 1mL. This may be tricky with something as thick and viscous as the SELCO but it's not necessary to be exact.

3. Second feed and enrich

After 12 hours, add another 1mL of algae paste, and 1mL of SELCO SPRESSO (or 1 drop of SUPER SELCO) per liter of water. Let the nauplii feed and ingest the SELCO for another 12 hours. This is necessary because the nutritional value of the HUFAs break down quickly in the presence of oxygen, and algae will decay in an aqueous environment.1, 2, 3 Breaking the enrichment into 12-hour blocks ensures the nauplii have access to the nutrients in the algae and SELCO.

Important: Do not enrich the nauplii with SELCO for more than 36 hours, they will eventually suffocate from the SELCO coating their gills.5 If you wish to perform multi-day enrichment for any reason, you will need to harvest and thoroughly rinse the nauplii on a regular basis.

4. Harvest nauplii

Repeat the process outlined above for hatching.

5. Rinse nauplii

Repeat the process outlined above for hatching.

6. Freeze remaining nauplii

After you have fed some enriched nauplii to your jellies, it is convenient to freeze the remainder for use later. Using the box sieve, concentrate the nauplii into a mass and drain as much water out of the sieve as possible. Using a turkey baster to get a thick paste of nauplii and gently inject the nauplii paste into the mini ice-cube tray. With 6 spoons of egg (and 2 live feedings), I usually have enough to fill around 8 ice cubes. Insert the tray into a freezer and retrieve at a later time.

References Additional information and where I found it

  1. Manual on the Production and Use of Live Food for Aquaculture
    The Food & Agriculture Organization of the United Nations maintains several free public aquaculture manuals to help relieve world hunger through the commercial and large scale raising of feed for various types of fish.
  2. Manual on Hatchery Production of Seabass and Gilthead Seabream
    The Food & Agriculture Organization of the United Nations maintains several free public aquaculture manuals to help relieve world hunger through the commercial and large scale raising of feed for various types of fish.
  3. Plankton Culture Manual, 6th Edition by Frank Hoff & T. Snell
    Frank Hoff pioneered many of the techniques used to captive breed marine life in closed aquarium systems. He served as the head biologist of the Aquaculture Division of the State of Florida and founded Florida Aqua Farms, which is considered a leader in aquaculture. Frank passed away in 2010 and his company is run by his children.
  4. Hatching Brine Shrimp Cysts by Brine Shrimp Direct
    Brine Shrimp Direct is a supplier of Utah salt-flat Artemia eggs. I have personally found them to be very helpful and knowledgable. You can simply call them up on the phone and receive very helpful advice.
  5. How to Keep Jellyfish in Aquariums: An Introductory Guide for Maintaining Healthy Jellies by Chad L Widmer
    Chad was the head curator of the jellyfish exhibit at the Monterey Bay Aquarium and his book is intended to help owners raise and breed their own jellyfish. Includes a few useful practical tips on how to raise and enrich Artemia nauplii for feeding jellyfish.
  6. The DHA/EPA difference
    Aquafauna Bio-Marine Inc. has a short summary explaining what the basic differences are between various types of HUFAs and why some HUFAs are more important than others.
  7. INVE Aquaculture
    INVE Aquaculture Inc. is a Belgian company founded by Patrick Sorgeloos. Dr. Sorgeloos was responsible for the scientific research in the 1970's that established Artemia as practical live feed for marine aquaculture.

Contact Information How to contact the author(s)

Jonathan Hsu

Jonathan Hsu

I was introduced to jellyfish by the cover of Wired magazine in late 2011, explaining how a company called Jellyfish Art would make keeping a jellyfish in the home as easy as taking care of a goldfish. This was, of course, patently false, but that didn't stop me from trying. After having fun doing a year of experimentation and research, I wrote this web-site to share what I found. I have started a coral reef tank, which I blog about, updating it with news about long-term coral health, new animals, or new tools and techniques to take care of the animals.

Email Jonathan