Species Diversity in Chydorid (Cladocera) Communities

Microfossil remains from surficial sediments of 20 Danish and 14 northern Indiana Jakes were counted, and their relative percentages calculated. Using the function H = — Σp° i log 2 °° species diversity was calculated for each lake. Indices of diversity for each lake and data on primary production and transparency were subsequently ranked and Spearman's rank correlation coefficient was determined between species diversity and production, and species diversity and transparency. Interpretation of results within the framework of information theory was not satisfactory. It is sugested that species diversity of chydorids is controlled primarily by complexity of the thier habitat, the rooted aquatic macrophytes of lakes.