ИСПОЛЬЗОВАНИЕ НАУПЛИЙ РАЧКОВ ARTEMIA SALINA В КАЧЕСТВЕ НОСИТЕЛЯ ПРОБИОТИКОВ БАКТЕРИЙ РОДА BACILLUS В АКВАКУЛЬТУРЕ

Abstract

This paper presents the results of the investigation of the effect of probiotic preparations based on Bacillus strains on Artemia salina nauplii. The use of live food is a necessary step in cultivation of many fish species, and Artemia nauplii are widely used for this purpose. It is crucial to use probiotics in aquaculture, as they can act as natural antagonists of aquatic pathogens, as well as stimulate fish growth and development. This work aims to study the immobilization of probiotic Bacillus strains on Artemia nauplii in order to develop highly effective feeds with probiotic properties for juvenile fish. Experiments on the introduction of various doses of preparations based on three probiotic strains of Bacillus into the water during the rearing of Artemia salina cysts were carried out. The number of bacteria in the water, as well as on the surface and inside the nauplii, was estimated by plating on nutrient media. It has been established that, despite the fact that brine shrimps do not feed at the orthonauplius stage, when probiotic strains are introduced into the water, bacteria are immobilized on the covers of the crustaceans; the concentration of the introduced Bacillus strains in the wipe samples taken from the nauplii surface is 1 order higher than it is for the planktonic form in the water. The introduction of bacilli at a dose of 0.0017 g/L activated the release of nauplii from cysts by 9-41 % of the control, while increasing the dose to 0.17 g/L led to a decrease in the proportion of hatched crustaceans. Thus, if the correct dosage were identified, it would make it possible to accomplish two important tasks at once: to obtain the live feed with probiotic properties for fish larvae and to increase the yield of nauplii.