Effects of a vertebrate predator (Poecillia reticulata) presence on Ceriodaphnia cornuta (Cladocera: Crustacea) in laboratory conditions

Aim: To detect the induction of morphological and populational alterations on Ceriodaphnia cornuta concerning cyclomorphosis and population dynamic parameters as densities, fecundity rates, juveniles percentage, males presence and ephippia presence in the presence of predators; Methods: Two experiments were performed: Experiments with fishes fed on Ceriodaphnia cornuta – Experiment 1 – and “Fish Water” Experiment – Experiment 2; Results: Main results observed include decrease in primiparous length and increase in Ceriodaphnia cornuta fecundity; Conclusions: The presence of vertebrate predators (Poecilia reticulata) influenced the Ceriodaphnia cornuta population dynamics at fecundity levels and primiparous; Due to the short duration of repetitions, it was possible to observe morphological changes and the production of ephippia; Ceriodaphnia cornuta is susceptible to the presence of vertebrate predators at the population dynamics level and not at the morphological plasticity; The changes occur in Ceriodaphnia cornuta, in the presence of vertebrate predators especially in population dynamics; Possibly C. cornuta presents different response behaviors for each kind of predator.