Artemia salina have three eyes and 11 pairs of legs and can grow to about 15 millimetres (0.6 in) in size. Their blood contains the pigment haemoglobin, which is also found in vertebrates. Males differ from females by having the second antennae markedly enlarged, and modified into clasping organs used in mating.
In nature, they live in salt lakes. They are almost never found in an open sea, most likely because of the lack of food and relative defenselessness. Artemia can live in water having much more or much less salt content than normal seawater. They tolerate salt amounts as high as 50%, which is nearly a saturated solution, and can live for several days in solutions very different from the sea water, such as potassium permanganate or silver nitrate, while iodine—a frequent addition to edible salt—is harmful to them. The animal's colour depends on the salt concentration, with high concentrations giving them a slightly red appearance. In fresh water, Artemia salina dies after about an hour. It feeds mainly on green algae.
Bio-encapsulated specific amounts of saltwater shrimp shrimp is rich in highly unsaturated fatty acid particles or emulsified products, the nutritional quality of Artemia can further adapt to the needs of predators. The application of this bioassembly method, also known as Artemia, is concentrated or enhanced, with a significant impact on improved aquaculture production, not only in the survival, growth and success of many fish and crustaceans, but also in Their quality, such as reduced malformations, improved pigmentation and resistance to stress. The same bioassembly method for oral delivery of vitamins, chemotherapeutic agents and vaccines is now being developed.
Artemia populations are found in about 500 natural salt lakes and man-made salterns scattered throughout the tropical, subtropical and temperate climatic zones, along coastlines as well as inland (Fig. 4.1.15.). This list still remains provisional as more extensive survey work should lead to the discovery of many more Artemia biotopes in different parts of the world (Table 4.1.1.). The distribution of Artemia is discontinuous: not all highly saline biotopes are populated with Artemia. Although brine shrimp thrive very well in natural seawater, they cannot migrate from one saline biotope to another via the seas, as they depend on their physiological adaptations to high salinity to avoid predation and competition with other filter feeders. Its physiological adaptations to high salinity provide a very efficient ecological defense against predation, as brine shrimp possess:
· a very efficient osmoregulatory system;
· the capacity to synthesize very efficient respiratory pigments to cope with the low O2 levels at high salinities;
· the ability to produce dormant cysts when environmental conditions endanger the survival of the species.
Artemia therefore, is only found at salinities where its predators cannot survive (³ 70 g.l-1). As a result of extreme physiological stress and water toxicity Artemia dies off at salinities close to NaCl saturation, i.e. 250 g.l-1 and higher.
Tags: Artemia salina