Parthenogenetic reproduction of Moina macrocopa (Straus 1820) (Crustacea :Cladocera): trophic conditions, population density, grouping and temperature influence

The fecundity and development of Moina macrocopa, the only cladoceran livin g in the waste water sedimentation ponds of Marrakech, have been studied in the laboratory at seven varying algal concentrations and at bye different temperatures. Population density and grouping effects were also investigate d. The conditions of food deficiency are one of the major cause of the reduced fecundity in Moina macrocopa. We showed, that an insufficient food supply corresponding to an algae concentration lower than 3. 125.10(4) cells/ml, w ould suppress (remove) any reproductive phenomenon. In contrast, the increa se of resource level beyond this reproductive concentration threshold, allo wed fecundity of Moina macrocopa to improve which appears as an increase in the brood number (frequency) rather than an increase of the brood size. The experiments also allowed us to show the harmful effect of an increase o f population density on the fecundity of M. macrocopa. However, no grouping effect on reproductive processes has been observed in this species.