Effects of substitution of manipulated beaker's yeast for Lansy PZ as feed on the growth and survival of Artemia urmiana and A. franciscana

Recently، due to the high costs and a decrease in producing of Lansy PZ، various researches have been paid attention to the baker''s yeast (Saccharomyces cerevisiae) as a substitute for Lansy PZ in Artemia cultures. In this study، the effects of six feeding regimes: Lansy PZ (as control)، enriched yeast with highly unsaturated fatty acids (HUFA)، enriched with HUFA and without mannoproteins in wall cells، yeast without mannoproteins in wall cells، industrial yeast 100% feeding regime and yeast 50% feeding regime in combination with the algae Dunaliella tertiolecta were examined on growth and survival of nauplii Instar I of two Artemia species (Artemia urmiana and A. franciscana) at a salinity of 80 part per thousands and a density of 500 nauplii per liter in laboratory cultures. Growth and survival of Artemia were determined in each group on 3، 7، 11 and 15 days after hatching. The two species of Artemia had the highest growth when fed Lansy PZ (P<0. 05). However، total length of A. urmiana (9. 09 mm) was higher than that of A. franciscana (7. 52 mm) when fed the Lansy PZ diet in 15th day. The two Artemia species had the higher survival rates when fed with yeast without mannoproteins (73. 20 and 75. 80%، respectively) than the Lansy PZ (60. 70 and 72. 07%، respectively) and other treatments. Our results revealed that the enrichment of the baker''s yeast with HUFAs and elimination of mannoproteins had a positive effect on survival rates comapred to growth of two Artemia species. However، the elimination of mannoproteins of yeast was a more suitable method in treatment of baker''s yeast as a diet for Artemia compared to other methods. Therefore، the yeast without mannoproteins treatment could be substituted with Lanzy PZ for Artemia feeding in different culture methods such as tanks or recirculated culture systems.