| The effect of different salinities (5, 10, 25 and 30 psu) has been investigated with salt-mixed freshwater on population growth and density of Copepoda and Cladocera in freshwater as they are unable to emigrate to escape the problem. The findings showed that difference in salinities give different effects on the population number of selected copepods cultured in the same temperature. The copepoda reared in 25 psu salinity showed the highest population density (mean of 3.7 ind/ml), but the most frequent population growth is showed in 35psu in the laboratory conditions. Daphnia carinata is used as a toxicological test species for water systems. The 45h-LC50 from studies salinities were 2.99, for sodium chloride solution. A survival and growth rate of daphnid was decreased with increasing salinity. The highest total reproduction (95± 0.1) neonates per female was achieved at 0.44% (LC10) for saline water over a period of 21 days.
Keywords: Zooplanktons, Neonates, Aquaculture, Salinity, Water quality.
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