Abstract

The straminipiles (Oomycota), lineage of fungus-like eukaryotic microorganism, growing on the eggs of an African catfish, Clarias gariepinus, in water of different trophicity in Poland have been investigated. Twenty-one (21) species were recorded. The largest number of species occurred on eggs in water from River Biala and Pond Fosa (more biogenic), the smallest in water from River Suprasl and Pond Dojlidy (poor in biogenes). The most commonly encountered species on the C. gariepinus eggs were: Saprolegnia parasitica, Achlya polyandra, A. oblongata, A. prolifera, Aphanomyces frigidophilus, S. ferax and Leptomitus lacteus. Amino-acid, carbohydrate and urease tests were used. 11.4% of C. gariepinus eggs investigated were found to be infected by Straminipiles species.

Key words: Clarias gariepinus, eggs, straminipiles (Oomycota), infections, hydrochemistry