Clonal Coexistence in <i>Daphnia pulex</i> (Leydig): Another Planktonic Paradox

Allozyme variation is common in populations of Daphnia pulex reproducing by obligate parthenogenesis. The genetic diversity within populations results from the coexistence of genetically different clones. Twenty-two clones were recognized in the eleven populations surveyed, of which as many as seven were found in a single habitat.