Abstract:

In order to compare species compositions of ostracods, 25 streams and 15 lakes were sampled in the spring, summer, and autumn seasons of 2018. A total of 26 ostracod species were found in lakes (18 spp.) and streams (12 spp.). The Shannon index (H') and evenness values of streams were higher than in lakes in all seasons. The highest H' values for all combined (lakes + streams) and lake data were reported in the autumn season, and in spring the highest values were in streams. According to the ß-diversity (ß) index values, the variability of ostracod species composition in lakes was higher than in streams, and its value was highest in spring (0.40) and lowest in summer (0.34) among all seasons for combined data. Pairwise comparison of spring and autumn displayed higher ß-diversity values than other comparisons, while its value was 0.41 between lakes and streams. According to canonical correspondence analysis results, elevation had a significant (P = 0.006) effect on distribution of species. All results suggested the importance of seasonality for evaluating the biodiversity of a region rather than the number of sampling sites, and the autumn season seems to be richer than other seasons in terms of species diversity.

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