Goussia carpelli (Apicomplexa, Eimeriorina) from cyprinid fish: field observations and infection experiments.

Intestinal tissue samples of 9 cyprinid and gobiid fish species from several hatcheries and ponds in South Bohemia were found to harbour Goussia carpelli-like coccidian oocysts. Furthermore, laboratory transmission of Goussia carpelli, obtained from common carp, was attempted to 9 cyprinid fish species, both laboratory reared and obtained from pond environments. Infection experiments, carried out by fecal contamination (direct transmission) and by using tubificid oligochaetes as paratenic hosts resulted in weak infections in 4 out of 15 Carassius auratus used, but it was not possible to infect any of the other fishes used.