LIX.—On the variability and status of the Cladocera <i>Ceriodaphnia cornuta</i> and <i>C. rigaudi</i>

Abstract

Summary The validity as distinct species of Ceriodaphnia cornuta Sars (1885) and C. rigaudi Richard (1894) is examined. On 15 populations from the Nile system the three main morphological characters regarded as specific have been found to be variable but correlated in development with each other. The two forms are not stable and constitute one variable species. It is concluded that C. rigaudi must be regarded as a synonym of C. cornuta (new synonymy).