The occurence of rare in Europe and new to Poland species Aulodrilus japonicus Yamaguchi, 1953 (Oligochaeta, Tubificidae) in two fishponds

In two fishponds (area of 1.6 ha and 0.2 ha, depth to 1.5 m) in Silesian Upland (Southern Poland) rare in Europe species Aulodrilus japonicus Yamaguchi, 1953 was found to the first time in Polish fauna. The water bodies are slightly acid, soft (total hardness up to 96 mg CaCO[3] l[^-1]) and nutrient rich. A. japonicus occurred during the whole study period (from March to November) in both ponds. The greatest abundance (up to 120 ind.m [^-2]) was observed in the summer, however the mature specimens were never found.