Ecological factors affecting the distribution of Volvox species in small ponds
Authors
Advisor
Issue Date
Keyword
Degree
Department
Other Identifiers
CardCat URL
Abstract
Factors influencing the distribution of Volvox spp. in 41 ponds of the Lake Itasca region, Minnesota, were investigated from May 25 through July 14, 1980. Twenty-two ponds had Volvox populations. The three species of Volvox found were: V. aureus Ehr., V. globator L. and V. tertius Meyer. Usually only one species was present in a pond with rare co-occurrence of two species. Only two of the 41 ponds contained two Volvox species simultaneously for a short time.Group comparison tests of ponds with and without Volvox showed three parameters to be significant (P > 0.05 level). Mean total phosphorus was higher in ponds with Volvox (x = 1.75 uM/1) than without (x = 0.95 uM/1). Mean temperature (20.4°C versus 21.8°C) and mean pH calculated from H+ concentrations (6.32 versus 6.76) were both lower in ponds with Volvox than in ponds without. Field observations of one pond revealed a patchy distribution of V. globator related to macrophyte abundance. Laboratory investigations confirmed that V. globator colonies orient to the aquatic moss Drepanocladus revolvens.Ball State UniversityMuncie, IN 47306