Diurnal fluctuation of spores of freshwater hyphomycetes in two tropical streams

[摘要] Diurnal changes in species and spore richness of freshwater hyphomycetes in relation to physicochemical features in two streams of the southwest India were compared using Millipore filtration during the post-monsoon season. Drift spores belonging to 16-19 species were recorded. Anguillospora longissima, Flagellospora curvula, Lunulospora curvula and Triscelophorus monosporus were dominant in both streams. The Pearson correlation revealed significant negative correlation between temperature and dissolved oxygen (p < 0.01) in both streams. The water temperature, pH and conductivity decreased between day and night, while the dissolved oxygen became elevated. Total species showed two peaks at 12 hr intervals (9 am and 9 pm) in both streams. The species richness, diversity and evenness were higher during the night than day in the Konaje stream, while it was reverse in the Mallapura stream. The species richness of both streams has no significant correlation with water quality. The total spores exhibited two peaks at 15 hr intervals (3 pm and 6 am) in both streams. The total spores differed significantly (p < 0.001) between streams and was higher during the night than day in both streams, possibly due to lack of leaf shredding invertebrates. Among the five dominant species, peak spore production of Lunulospora curvula in both streams coincided with the peaks of total spores. The spore richness in the Konaje stream had no significant correlation with water parameters, but showed significant negative correlation with temperature in the Mallapura stream (p < 0.05). This study revealed contrasting results in diurnal fluctuation of spores of freshwater hyphomycetes compared to temperate region.

[学科分类] 植物学

[关键词] diurnal periodicity;freshwater hyphomycetes;Millipore filtration;spore concentration;water quality