Effect of trophically different water bodies on the straminipilous fungal infection of Stenodus genus (Coregoninae) eggs

The authors investigated the growth of straminipilous organisms on the eggs of inconnu (Stenodus leucichthys) and nelma (Stenodus nelma) in water from three different eutrophication levels. Thirty (30) straminipilous species were found growing on the investigated eggs (of both fish species) used as baits. The majority of species has been found on the eggs of inconnu (20) in comparison with those found on the eggs of nelma (15). The highest number of infected eggs of both investigated species has been observed also in the water from Biala river (27.3% of the inconnu and 21.6% of the nelma; the most eutrophication), the smallest in water from Supraśl River (6.3 and 8.8% respectively; the less eutrophication). These differences for both species were statistically significant. Amino acid, carbohydrate and urease tests were used.   Key words: Inconnu, Stenodus leucichthys, nelma, Stenodus nelma, fish eggs, straminipilous organisms, eutrophication.