Decapsulation of artemia cysts (Artemia sp.) using different versions of sodium hypochlorite solutions (NaOCL)

The article describes the technology of Artemia decapsulation, its features and external factors affecting the efficiency of hatching with subsequent use as a feed composition. Artemia nauplii and its eggs, due to their high nutritional value and high digestibility in the digestive tract, are widely used in growing sturgeon larvae and other fish species. Artemia decapsulation is one of the most important factors in the transition of fish larvae to active feeding, in this regard, it is very important to select the optimal decapsulation conditions, the composition of chemical reagents, temperature and light conditions. The decapsulation process is a chemical process of removing the hard shell that surrounds the Artemia embryo. The procedure involves hydration, during which the outer shell is removed, can be carried out with a number of solutions: sodium hydroxide, sodium carbonate, sodium hypochlorite, hydrochloric acid. However, they all show different availability and efficiency in decapsulation. The most common is the use of sodium hypochlorite solutions, but they do not show stable results, since the process of decapsulation and hatching of nauplii from cysts depends on many factors. The aim of the work was to study the methods of decapsulation of Artemia eggs for their use as a starter feed when transferring to active feeding and feeding of sturgeon larvae. As a result of the experiments, a technology for incubating Artemia eggs in accessible conditions without the use of professional equipment was developed. Cysts are incubated in aerated Weiss apparatuses, under constant illumination, in a volume of 7 liters of water, at a concentration of: NaCl — 30%, artemia cysts 3 g/l, water temperature — 28 °С. The cysts are decapsulated without soaking, with 2.5% NaOCl solution with a total volume of 300 ml (21 g of dry cysts + 150 ml of water + 150 ml of NaOCl) for 4–5 minutes.