Diurnal Fluctuations in Population Density of Ostracoda in Relation to Some Physical and Chemical Parameters from Yassbolagh Dam, Yassbolagh village, Markazi, Iran

Diurnal fluctuations in population density of ostracoda in relation to temperature, dissolved oxygen, pH, acidity and alkalinity were studied. The study covered four diel periods in three months of summer. Codification correlation, ANOVA and Correlation test were used for analyzing the biometrical study. In the present study only four species from three genuses of ostracods were present, Cypris showed the maximum population density among the geniuses, while the population density of Eucypris nobilis was maximum throughout the study. Possibly their high population density in 6 and 24, is due to nocturnal habitat and photophobic life.