The Chydorid Crustacean Alona diaphana (King), Limnetic in Lakes Awasa and Zwai,Ethiopia, with a Discussion of Littoral and Limnetic Zooplankton

Alona diaphana, a common littoral tropicopolitan cladoceran, occurs in the limnetic of two Ethiopian lakes in considerable numbers and over long periods of time. Our results are presented and the composition of limnetic and littoral zooplankton, in terms of previous records of such incursions, are discussed. The high persistent densities of A. diaphana are due to the extensive littoral areas in the lakes, where it originates, the high intrinsic rates of increase of this species, the low diversity of zooplankton, reducing competition and the low level of predation.