Effect of algal monocultures and combined algal drug on the survival of artemia nauplii

Abstract

The maintenance of live feed in automatic feeders is accompanied by fasting of fodder organisms, resultedin a lose of their nutritional value and even death. The way out of this situation can be the joint maintenance of Artemia nauplii and their fodder objects – microalgae. Accordingly, an influence of three microalgae monocultures (Desmodesmus armatus, Chlorella vulgaris, Dunaliella salina) and the AlgaMac Protein Plus drug on survival of Artemia nauplii was analyzed. It was shown that the lowest mortality rates of brine shrimp were observed when it was co-cultivated with monoculture of Chlorella. The use of the AlgaMac Protein Plus algal drug provided a significant reduction in the mortality rate of Artemia nauplii at 12 hours of cultivation. Cell size of studied algal species is a key point for their using as a fodder object for brine shrimp. Maximum diameter of Chlorella cells reaches 10 μm. Cells of D. armatus are single nucleated autospores with coccoid shape. Their size is 10-20 microns in length; 3.5-8 microns in width. However, exept of single cells, Desmodesmus forms conglomerates in 2-4 cells, which complicates its capture by Artemia. Algae of the genus Dunaliella are the component of the natural feed base for Artemia in salt and hypersaline lakes. Despite the fact that these algae are actively consumed by adult Artemia, for their early stages Dunaliella remains practically inaccessible, as it has large enough cells of a pear shaped form up to 25 microns in length and 4 to 10 microns in width. The initial length of Artemia nauplii after hatching was about 551 μm. In the control sample after 24 hours, this parameter was increased to 625 microns. In the experimental sample, co-cultivated with Dunaliella the size of brine shrimp was 617 μm, while enriching with Chlorella this parameter was 611 μm. The smallest size was observed in nauplii co-cultivated with D. armatus. Key words: live feed, Artemia, microalgae, mortality, AlgaMac Protein Plus.