Artemia, Fairy shrimp

Artemia live in salt lakes, for example in Mono Lake (Utah) or in North Africa. They are also often found in basins for sea salt production. In Europe and North Africa, Artemia make up a big part of the diet of flamingos, their coloration stems from the reddish Artemia.

Example video of Artemia (several weeks old)

In Germany, there is an occurrence of Artemia franciscana near Bleicherode. In several lakes there, seepage water from the waste of the salt mines collects. The Artemia was probably introduced by migratory birds, but the source has never been verified. The Artemia are bred and marketed as fish food. Artemia itself filters algae and plankton from the water. The physique of fairy shrimp is such that they swim on their backs. The pairs of legs pointing upwards beat in waves. Many photos on the internet do not show the correct swimming orientation! Due to the wavy beating of the swimming legs, food particles are also transported into the upper food channel and from there into the mouth. The intestinal contents can be seen as a dark line along the body and are also differently coloured depending on the food. Males and females differ mainly in the structure of the antennae on their heads. Males have a grasping organ to hold on to the female. Older females have clearly visible egg sacs in the middle of the body. In addition to the introduced saltwater species, there are also some wild occurrences of freshwater fairy shrimp (e.g. the genera Eubranchipus, Branchipus) in Germany in alluvial forest pools, river floodplains or seepage water behind river dikes. In spring and summer fairy shrimp can still be found in a few places in Germany, but they are rare and protected by lay.

Overview material for the Artemia culture - preparation vessel approx. 2-3 L (preserving jar, glass bowl, mini aquarium or fauna box)

• Sea salt (if possible unpurified, without additives, about 100g)
• Sodium hydrogen carbonate "Natron” in German, or “baking soda" approx. 5g. It should not contain other additives, like phosphates
• Artemia cysts (Microscope accessories, or purchased from a pet shop / aquarium store)
• Feed (dried yeast, powdered feed, spirulina powder, flower pollen, "green water")
• Pipette, if necessary thin rubber tube to remove animals from breeding tank or change water
• Petri dish or other small vessels for observation under a microscope

Artemia permanent eggs (cysts) can be found as an accessory in some microscope models. As Artemia nauplii are used as food for rearing young fish, Artemia cysts, complete mixtures with salt as well as some live cultures are available in pet shops or from a fishkeeper. Feedstuffs (e.g. algae powder, powdered feed for rearing young fish) are also available in pet shops. An alternative source of food (pollen, algae powder as a food supplement) is an organic food store or the food supplement section in a supermarket.

The permanent eggs are prepared with tap water. Add one tablespoon (approx. 10-15g) of sea salt without additives per 0.5l of water. Unpurified grey sea salt is ideal. To make the pH slightly alkaline (pH about 7.5-8.0), a pinch of sodium hydrogen carbonate "Natron” or “baking soda" can be added per 0.5L. If the water is chlorinated or contains copper (e.g. from pipes, heaters), you can use mineral water that is low in minerals and has a neutral pH (e.g. Volvic) for the preparation, as invertebrates are very sensitive to chlorine and heavy metals.

This is especially true if you want to breed Artemia-related freshwater crayfish (e.g. fairy shrimp Streptocephalus or Branchinella, which require particularly pure, soft water).

It is best to use a rather shallow vessel for the setup to ensure sufficient air exchange at the water surface. The container should be bright, at room temperature, but not directly in the sun.

After 24-48 hours at room temperature the first 0.3mm to 0.5mm large larvae, called nauplii, hatch. They paddle through the water with the rudder antenna pair.

The Artemia initially shed their skin at very short intervals (a few hours). Only after several moltings does the number of pairs of legs increase. At the latest 2 days after hatching you should feed carefully. For this purpose (depending on availability) one uses a little slurry of dry yeast, spirulina powder, powdered food from pet shops, pollen, or green algae from a pond or pool ("green water", usually chlorella or similar small algae). It is important to feed as sparingly as possible and to wait each time until the water is clear again.

Artemia can live from a few weeks to a few months. In order to keep the culture as long as possible, you can suck off any debris and food residues at the bottom with a pipette. Evaporated water can be filled up with rain water or distilled water. Every week you should also replace part of the water. It is important to change the water carefully; the fresh water should have the same temperature and composition and be added over a period of at least 1-2 hours. With a bit of luck, the culture can be maintained for up to 6 months (max. age). With a little luck, new cysts can be found lying on the bottom, which can be dried on a sheet of paper. A new generation can hatch from them.

The animals can be observed optimally with a reflected light microscope. For this purpose, a few animals are placed in a Petri dish in a little water. Smaller animals can also be transferrred with a pipette with as large an opening as possible or aspirated with a thin tube.

When using a microscope, the sample may heat up due to the microscope illumination. Care should be taken to keep observation times short. During breaks, switch off the light and remove the bowl with the animals from the microscope! After observation, return the animals quickly to the culture vessel.

Have a look at our microscopes to take such pictures yourself! Have fun!

Sources

Wikipedia

Literature on occurrence in Germany:
Report 1

Further suitable information
What is Artemia?
Artemia rearing the nauplii
Artemia Living Food Light Homemade