Effect of sample size on the detection of species and conidial numbers of aquatic hyphomycetes collected by membrane filtration
Gönczöl, János; Révay, Àgnes; Csontos, Péter
Archiv für Hydrobiologie Volume 150 Number 4 (2001), p. 677 - 691
published: Feb 15, 2001
ArtNo. ESP141015004008, Price: 29.00 €
Aquatic hyphomycete conidia of the Boros stream, Börzsöny Mts. were sampled in September and October by membrane filtration. Effect of water sample volumes, and area of membrane filter scanned, on the numbers of identified species and conidia were examined. The membrane filters were divided into four equal pieshaped sections and trapped conidia were counted and identified separately on each quadrant. The examination of a half filter area proved to be sufficient, but greater reduction of examined filter area resulted in the loss of important data. Saturation curves were used to demonstrate species number - sample volume relationships. In both September and October the saturation levels were not reached within the investigated water volumes. The minimal volume of water needed to detect 90 % of all species present was 1100 ml in September and 1350 ml in October. When species with frequencies > 20 % were considered, complete saturation was achieved for both sampling occasions with a water volume of 750 ml, with maximum number of species 14 in September and 31 in October samples. The results of this study suggest that the examination of water samples collected and combined from several smaller subsamples allow a more accurate appraisal of species numbers present in the field than that of a large homogeneous mass of water.