Growth and grazing responses of tintinnid ciliates feeding on the toxic dinoflagellate Heterocapsa circularisquama

Two species of tintinnids, Favella taraikaensis and F. azorica, were fed a diet of the toxic dinoflagellate Heterocapsa circularisquama to determine their growth, grazing and feeding responses. Results showed that temperature and prey density affect feeding behavior of ciliates and high concentration of prey algae causes high ingestion rates but decreased growth rates. Furthermore, the grazing of F. taraikaensis cannot control the development of H. circularisquama blooms at high concentrations of H. circularisquama.