The functional response of copepodid stages to adult ofParabroteas sarsi (copepoda, calanoida) (original) (raw)

P. sarsi is a carnivorous calanoid commonly found in South Andes lakes. Feeding experiments were camed out in order to analyze the functional response of P. sarsi (copepodid IV to adult) on different cladoceran prey. Predation rates increased with increasing prey density up to maximum (type 11) in almost cases. The highest attack coefficients were obtained when P. sarsi adults were fed with the smaller prey (C. dubia juvenile and B. Iongirostris). The ingestion rates of copepodid IV and CV were smaller than for the-adults. The ingested biomass as a proportion of predator biomass (B,/B,) showed an inversal relationship with the predator length. The maximum BJB, ratio, in both sex of P. sarsi, was achieved with C. dubin adult, the intermediate-sized prey.