Morphological variation of the Caloneis schumanniana species complex (Bacillariophyceae) from different environmental conditions in North American streams.

Morphological variations of the Caloneis schumanniana (Grunow) Cleve species complex were studied using multivariate analysis. Populations of three species, synonymized in the literature, i.e., C. schumanniana, Caloneis limosa (Kützing) Patrick and Caloneis lewisii Patrick, were analyzed. Their morphological and ecological characteristics were evaluated and outlined for the sampled streams by US EPA’s Western Environmental Monitoring and Assessment Program. Geographic separation among the three taxa was not resolved. This study showed that C. schumanniana has wider ecological tolerance than C. limosa and C. lewisii. Despite the ecological overlap, specific ecological preferences of C. limosa and C. lewisii were described. [ABSTRACT FROM AUTHOR]