Occurrence of Motile Gametes in Prasiola stipitata Suhr

Abstract

THE apparent absence of sexual reproduction in the Prasiolaceae has been one of the notable features of this family. It was of considerable interest, therefore, when two decades ago, Yabe¹ announced that sexual reproduction occurs in the freshwater species Prasiola japonica Yatabe and is effected by the fusion of anisogamous biflagellated gametes. Fujiyama^2,3, also using material of P. japonica, has confirmed Yabe's observations in the main essentials, except that he considers the female gamete to be non-motile. For all that, doubts about the sexual reproduction of Prasiola have been expressed quite recently by Fritsch⁴ and Smith⁵, although Fujiyama's second paper could not have been seen by these authors at the time they wrote.