Ó Temporal Changes in Gametogenesis of the Invasive Chinese Pond Mussel Sinanodonta woodiana (Lea, 1834) (Bivalvia: Unionidae) from the Konin Lakes System (Central Poland)* Piotr HLIWA, Bogus³aw ZDANOWSKI, Grzegorz J. DIETRICH, Aneta ANDRONOWSKA, Jaros³aw KRÓL, and Andrzej CIERESZKO F F F F The Chinese pond mussel, Sinanodonta woodi- ana (Lea, 1834), is one of the largest unionid spe- cies native to the Amur-Yangtze river basin (WATTERS 1997). S. woodiana arrived in Poland from Hungary with herbivorous cyprinid fish fry in the late 1980’s and since then a large population has become established in the Konin lakes system, in specific heated waters (AFANASJEV et al. 2001; KRASZEWSKI &ZDANOWSKI 2001). Initially the presence of S. woodiana was related only to the heated water of Konin-P¹tnów and Dolna Odra power plants but at present there are about ten con- firmed locations of this species in different parts of Poland (URBAÑSKA et al. 2012). Like many invasive species, S. woodiana consti- tutes a significant threat to its new environment. It is established that S. woodiana may compete for food with the local native population of molluscs in the Konin lakes system similarly to competition between native and invasive unionids in North America (DOUDA et al. 2012). The Chinese pond mussel is likely to compete for hosts with native European unionids which release their glochidia at the same time (BLAZEK & GELNAR 2006). _______________________________________ *Supported by University of Warmia and Mazury in Olsztyn (grant number 18.610.003-300); Inland Fisheries Institute in Olsz- tyn (grant number S-009).