Articles by Taxonomic Group

During studies concerning the occurrence of some fungi and fungus-like organisms in the Biała River in Bialystok, forty-three species were established. Among 34 straminipilous fungi, the most common species were Achlya americana, A. debaryana, A. polyandra, Aphanomyces laevis, Dictyuchus monosporus, Pythium debaryanum, Saprolegnia ferax, and S. parasitica. New for the Polish fungal biota were Achlya ambisexualis, Calyptralegnia basraensis, and Achlya papillosa. Achlya crenulata, A. diffusa, A. flagellata, Aphanomyces stellatus, and Pythium afertile were considered rare. Physical and chemical analysis showed that the water of Biała River in Białystok had a high content of ammonium nitrogen and phosphate, reflecting poor cleanliness.

Excretion into the environment of dissolved organic matter produced during photosynthesis is a characteristic phenomenon for several species of aquatic macrophytes (Wetzel 1969 a, b). Several of these substances are imbibed by heterotrophic microorganisms and may also inhibit the growth of other hydrobionts. An examination of the interactions between macrophytes and aquatic fungi showed that during the growing period (spring, summer and autumn), relationships between these organisms change. At the beginning of the growth period, the number of species of aquatic fungi rose in the presence eight macrophytes; during the summer there was a decrease in the number of fungi observed; while in the autumn (end of the growing season) there was an inhibitive influence of macrophytes on the growth of aquatic fungi, which was higher in eutrophic water. This inhibitive influence depends probably on the storage of any secondary compounds during aging of several macrophytes, which inhibit the growth of several species of fungi and fungus-like organisms.

The growth of aquatic fungi and fungus-like organisms on the predatory heteropter Notonecta glauca was investigated in laboratory conditions. Water samples were collected from four sites varying in trophicity: Cypisek Spring, Biała River, Supraśl River, and Komosa Lake situated near Białystok. Certain physico-chemical parameters were determined in the samples. The highest contents of carbon dioxide, ammonium nitrogen, phosphates, and chlorides were noted in Biała River. Twenty-eight fungi and fungus-like organisms were isolated from Notonecta glauca, including 6 species of Chytridiales, 2 species of Blastocladiales, and 20 species of oomycetes. Fourteen fungi and fungus-like organisms were identified in Cypisek Spring, 8 in Biała River, 17 in Supraśl River, and 10 in Komosa Lake. Worthy of note is the finding of some aquatic fungi which have been commonly encountered on chitin-containing substrata, namely Aphanomyces astaci, A. amfigynus, Chytriomyces hyalinus, Phlyctorhiza endogena, Podochytrium chitinophilum, Rhizidium chitinophilum, and Rh. nowakowskii.