Frequency, abundance and distribution of zoosporic organisms from Las Cañas stream (Buenos Aires, Argentina)

Abstract

Zoosporic organisms are common inhabitants of aquatic environments; however there are few ecological studies made for Argentinean streams. In this contribution the taxonomic composition of zoosporic organisms from a stream and their abundance, frequency and diversity on cellulosic baits were analyzed. Samples of water and floating organic matter (vegetable debris) were taken at four dates and different environmental variables (temperature, dissolved oxygen and nutrient concentrations) were measured. Twenty-one taxa were recovered with the baiting technique. Physicochemical fluctuations affected the structure of the studied community; in spring the greatest species richness was related to high nutrient levels whereas in winter the greatest abundance and diversity was related to low water temperature, nutrient levels and well oxygenated conditions.

• aquatic environment
• cellulosic substrates
• Chytridiomycota
• Peronosporomycota

This research was supported by grants of the Argentine National Research Council (CONICET, PIP 5931) and the National University of La Plata (N 11/440 Proyect).