Artemia salina is a crustacean inhabiting salt lakes and estuaries in almost all parts of the world. Due to its biological peculiarities, it has become a model organism. In 1982, it was in space orbit, where a joint Soviet-French crew studied with the help of this species the effect of cosmic radiation on living organisms. And in industrial fish farming and aquaristics Artemia salina is an indispensable food when feeding fish fry.
Latin: Artemia salina
Artemia salina Habitat
Artemia salina is a collective name. The fact is that Artemia salina species described by Carl Linnaeus around 1758 lived in the British Lake Livingstone. To date, this lake does not exist, and the Artemia salina living in its waters is officially recognized as extinct. But observing the habits, traditions and for simplicity among aquarists, this name is fixed for all European species of Artemia. Today there are seven main species of this crustacean.
- Artemia tunisiana (North Africa, Europe)
- Artemia species (part of Europe, America, Asia)
- Artemia franciscana (part of Europe, America)
- Artemia parthenogenetica (Australia, Africa, Europe, Asia)
- Artemia sinica (China, Central Asia)
- Artemia persimilis (Аргентина)
- Artemia urmiana (Iran)
As we can see Artemia salina, if we consider this name as a collective name for the above species, is distributed almost everywhere. It inhabits salty water bodies with a salt content of 40 to 300 ppm (mg / l). At such values of water salinity can not exist any other organisms except Artemia salina and some species of unicellular algae. Thus, this crustacean is protected from possible natural enemies by an ecological barrier insurmountable for predators.
Artemia salina Description
Depending on the species and habitat, they naturally have some species-specific characteristics. Namely, the length of the adult body can vary from 10 to 20 millimeters.
Water salinity can also influence morphology and reproduction method. So back in 1875 and 1877 Odessa biologist V. Shmankevich, growing A. salina at different water salinity, showed that it determines the features of morphology of crustaceans. Such as the length of the furca and its supply of bristles, as well as a number of other morphological features that are not so important to the aquarist. It should also be noted that there are species capable of parthenogenetic reproduction. Very strongly on the method of reproduction affect the environmental conditions. So under optimal conditions, females are able to nurture eggs inside their egg sacs to the state of nauplii. If sharply deteriorating conditions of existence – a decrease in the food base, a sharp drop in temperature – females hatch cysts, which have a fantastic ability to preserve life.
Thus, when drilling a well near the Great Salt Lake (Utah) in 1979, a soil sample between two salt beds contained cysts of A. salina. After incubation, the nauplii of the crayfish hatched from these eggs. Radiocarbon analysis determined the age of the bed that contained these cysts to be about ten thousand years.
The average length of newly hatched nauplii is 0.45mm, their mass is 0.01mg. Until the first molt, which occurs after 10 – 12 hours, nauplii do not feed. And after the transition to the second larval stage, begins to filter water and absorb bacteria, unicellular algae and detritus. Up to the adult state under optimal conditions can reach in eight days, making up to fifteen lines. Artemia salina lives for about six months.
Artemia salina as aquarium fish food
Artemia salina is a food not only for aquarium fish, but it is also used to feed commercial fish at fish farms. Namely, when feeding sturgeon fry, it is impossible to do without this crustacean. Since they do not eat non-living food, no matter how nutritious it may be. That is why technologies of keeping and breeding of these crustaceans have been developed to satisfy the industrial scale. There are also mentions of keeping this crustacean in relatively small aquarium farms.
But for the amateur constrained by the size of the city apartment breeding of this food is still problematic. For the amateur aquarist seems more acceptable to purchase cysts of crustaceans and the derivation of nauplii with the help of apparatus weiss. Also for such fish as barbs can do without it. On the shelves of pet stores can be found decapsulated eggs A. salina, which are eaten by the fry of many fish with great pleasure.
Who should be fed artemia nauplii?
On nauplii A. salina transferred usually fry spawning fish, which are already small for feeding infusoria. And large fry of almost all viviparous and some spawning fish can eat eggs or nauplii of this crustacean from the first day. Cysts for feeding fry should be decapsulated. And feeding decapsulated cysts seems not only easier, but also less dangerous. Decapsulated eggs before feeding should be poured for twenty minutes with water, after which it is desirable to wash them with running water in a net made of dense cloth to remove decay products that may have formed during prolonged storage.
This eliminates the need to incubate and build a hatchery. Practically reduces to zero the danger of infection of the growing aquarium of any infection. And completely eliminates the possibility of attack nauplii on the fry. This can sometimes happen in marine aquariums due to the fact that the nauplii A. salina grow much faster than the fry fed fish. Egg feeding probably has only one disadvantage. Eggs fall to the bottom instead of floating in the water column. And not all fish fry are able to pick them up from the bottom.
Weiss apparatus for breeding Artemia salina crayfish
The only way out in this case is to build a weiss apparatus. And the removal of nauplii immediately before feeding. The simplest weiss apparatus is a plastic bottle turned upside down. The bottom of this bottle should be cut off. The cork or neck of the bottle should be provided with a sprayer, in any convenient way. Two such bottles will be needed. Each bottle should be filled with one liter of a solution of common table salt or, better, sea salt.
Do not take iodized salt or salt with any other additives. The solution is prepared at the rate of three tablespoons of salt per two liters of water. In the bottle pour cysts of A. salina – one teaspoon without top for one liter of water. In general – that this crayfish is very prolific, but at home breeding nauplii output from cysts equal to 40 percent is considered very high, so you should take cysts with some excess.
After 24 hours, charge the second bottle with eggs in the same way. After another 24 hours in the first bottle will appear in the nauplii, which can be fed to the fry, and the vacated container charged with a new portion of eggs. Atomizers should be fed air pressure so that the eggs do not settle to the bottom, and were all the time in suspension. The temperature should be maintained at 28 to 30 degrees Celsius. Approximately half an hour before feeding fish stop the air supply. In this case, the empty shells rise to the top and not opened cysts sink to the bottom. Floating in the water column nauplii can be strained through a tight net with a hose. The decanted saline solution can be poured back into the incubation tank.
Nauplii can be placed in a jar of fresh water for additional washing off of salt. After that, they can be given to fry. In this case, it should be borne in mind that the hardiest individuals A. salina in fresh water live no longer than six hours. If you feed the fry of marine fish, you should give such an amount of nauplii Artemia salina, so that they were immediately eaten. Otherwise, due to the incomparably higher growth rate of the crayfish after a few days, food and eaters can change places. It is unlikely that you planned this.
- A. salina cannot sleep. It needs to be awake all the time to feed and breathe.
- Artemia salina has been living on Earth for about 100 million years and is a contemporary of the dinosaurs. The only older species is the Shieldbill (Triops cancriformis), which appeared more than 220 million years ago.
- Artemia salina has three eyes. One simple, appearing at the nauplius stage, the adult develops two more complex eyes.
- The egg sac of a female can contain up to 200 eggs.
This is such an amazing creature Artemia salina. It can not decorate the aquarium, in addition, its long-term maintenance is associated with some difficulties, but if you decide to engage in breeding aquarium fish without knowledge of such a valuable type of food as Artemia salina you can not do.