%0 Book part %A Sárkány-Kiss Endre %D 1997 %G English %B Tiscia monograph series %B The Cris/Körös rivers' valleys : a study of the geography, hydrobiology and ecology of the river system and its environment %@ 1418-0448 %T Structure and aspects of dynamic of the unionid associations of the Crişul Alb/Fehér-Körös river at Ineu %U http://acta.bibl.u-szeged.hu/10144/1/tiscia_mono_002_203-207.pdf %X The author examined the dynamic of growth of the Unio crassus species in Cri§ul Alb/Fehér Körös river before Ineu. In 1994 there were lifted out 800 samples of a 1 m wide cross-section of the river, they were numbered and then put back into the river. In 1995 there were found numbered samples. It was stated that the rhythm of growth slowed down in the 3rd-4th year of their life, which coincides with their sexual naturalization. The growth of the older age-classes is slow, it is only the rhythm of growth of weight that remains fast, owing to the thickening of the shells.