Articles by Taxonomic Group

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.

Straminipilous organisms and fungus species on dead fragments of 25 taxa of wetland plants from three water bodies were investigated. A total of 219 fungal taxa, including 85 straminipilous organisms and 134 fungus species were recorded. The largest number of straminipilous organisms and fungus species occurred on fragments of Lathyrus palustre and Rorippa amphibia (45 and 44 species respectively), the fewest on Calla palustris (20). The most common species were Chytridium xylophilum (on 23 plants), Pythium rostratum (on 15), Pithomyces obscuriseptatus (on all plants), Trinacrium subtile (on 17) and Titaea (Tetracladium) maxilliformis (on 16). The larger numbers of species were recorded in running water (Jaroszówka Spring, Supraśl River, 124 and 122 respectively), with fewest (106) in stagnant water at Dojlidy Pond. Thirty-one taxa were recorded for the first time from Poland.

The authors investigated aquatic fungi and chromistan organisms growing on the dead specimens of 11 species of free-floating plants in the water from three limnological and trophical different water bodies (spring, river and pond). On the specimens investigated plants in the water of water bodies of north-eastern Poland they identified 129 species including 57 chromistan organisms and 72 fungus species. The most common taxa were Aphanomyces laevis, Thraustotheca clavata, Pythium inflatum, P. rostratum, Anguillospora filiformis, A. pseudolongissima, Angulospora aquatica, Heliscus submersus, Lemonniera aquatica, Pithomyces obscuriseptatus, Tetracladium marchalianum, Tricellula aquatica. Most fungus species were observed on the specimens of Utricularia minor, U. vulgaris (each 36) and Hydrocharis morsus-ranae (34), fewest on Lemna gibba (22), Aldrowanda vesiculosa and Lemna minor (each 23). The most taxa were growing in the water from River Supraśl (64), the fewest in the water from Spring Jaroszówka (55). A number of chromistan organisms and fungus species (2 and 11 respectively) appeared new to Polish waters.

Aquatic fungi and fungus-like organisms, growing on nuts of seven birch species (Betula gracilis, B. humilis, B. lutea, B. nana, B. papyrifera, B. pubescens and B. verrucosa) found in the water of three limnologically and trophically different water bodies (spring, river and pond), were investigated. The total of 63 species, including 23 fungus-like organisms and 40 fungal species were found on the nuts of the investigated birches. The most common species were Karlingia rosea, Nowakowskiella macrospora, Achlya americana, Aphanomyces laevis, Saprolegnia ferax, Acrodictys bambusicola, Angulospora aquatica, Arbusculina fragmentans, Canalisporium caribense, Heliscus lugdunensis, Pithomyces obscuriseptatus, Tetracladium marchalianum and Tripospermum camelopardus ). Most of the species were observed on the nuts of Betula verrucosa (49 species) and the fewest on the nuts of Betula nana (42). In Cypisek spring, the number of fungal species and fungus-like organisms on the nuts was closely associated with the concentration of chlorides.However, in Supraśl River and Dojlidy pond it was associated with the sulphates concentration (in both cases negative correlation).

The authors investigated aquatic fungi and chromistan organisms (fungus-like organisms) growing on dead fragments of 7 species of floating-leaved plants (Limnanthemum nymphoides, Nuphar luteum, Nuphar pumilum, Nymphaea alba, Nymphaea candida, Polygonum amphibium f. natans and Potamogeton natans) in the water from three limnological and trophical different water bodies (spring, river and pond). They identified 106 species including 42 chromistan organisms and 64 fungus species, found on the fragments. A number of chromistan organisms and fungus species (Catenomyces persicinus, Nowakowskiella profusa, Polyphagus parasiticus, Rhipidium americanum, Rhipidium interrupta, Rhipidium partenosporum, Sporodina grandis, Endophragmiella latifusiformia, Pseudocercospora manuensis and Saprochaete ramosissima) are recorded as new to Polish waters.

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.