Culture of fish food organisms

Unit 8 - Brine Shrimp or Artemia

8.3.Brine shrimp-morphology and physiology
Morphology of artemia cyst
There is a variation in the size, dry weight and energy content of the strains. Hatching quality, percentage hatching rate and efficiency varies although hatching quality mainly depends on collection site. Temperature and salinity significantly affects survival and growth. Total lipid content and amino acid composition also varies depending on the strain.

Cyst consists of three layers
The first layer is hard with lipoprotein, chitin and hematin. The hematin imparts dark brown colour to the layer. This layer provides protection against any kind of mechanical and UV radiation. This layer can be removed by oxidation (decapsulation) by hypochlorite.

The Second layer is the outer cuticular membrane which is a multilayered membrane with special filter. This protects the embryo from molecule larger than CO₂ and acts as permeability barrier.

The Third layer is the embryonic cuticle which is transparent, highly elastic. It develops into hatching membrane during hatching.