SPECIATION IN MONOGONONT ROTIFERS

Monogonont rotifers are cyclical parthenogens living in limnic habitat s with considerable seasonal variation and often with island-like feat ures. The occurrence of bisexual reproduction in these organisms makes it feasible to define 'fields for gene recombination', i.e. biologica l species. In this paper, we analyze the structure of the diversity in monogonont rotifers using several data sets: taxonomic and intraspeci fic diversity as reported in identification keys, morphological variat ion reported in ecological studies, and allozyme and mating behavior p atterns. Our analysis suggests that sibling species may be frequent in rotifers. Monogonont rotifers seem to meet conditions for an active s peciation, which might be particularly promoted by seasonal specializa tion and timing of bisexual reproduction.