Available Online: http://www.ejpau.media.pl/volume3/issue1/fisheries/abs-02.html
ATTACKS OF CYCLOPOID ACANTHOCYCLOPS ROBUSTUS (SARS) ON NEWLY HATCHED CYPRINIDS
Waldemar G. Piasecki
Two experiments on newly hatched, 1-d-old, immobile and non-feeding larvae of carp (Cyprinus carpio Linne) and crucian carp (Carassius carassius (Linne)) were performed. Each experiment involved 3 treatments: WA (larvae + Acanthocyclops robustus); WAD (larvae + A.robustus + additional food for the cyclopoids consisting of Daphnia magna, rotifers, and ciliates); and W (larvae only; control). The carp larvae experiment took 5 days, while the crucian carp one proceeded for 6 days. During the experiments, the number of larvae in each treatment, their condition, degree of damage by A.robustus attacks as well as behaviour of both the larvae and cyclopoids were checked. The experiments demonstrated that A.robustus did attack the larvae, the attacks resulting in a considerable mortality. The mortality rate depended on the cyclopoid density as well as on the presence and quality of an alternative food supply. The attacks were most frequently effected by males and
Key words: copepods, fish, predation.