Merged with duplicate record 10026.1/2011 on 10.04.2017 by CS (TIS)Merged with duplicate record 10026.1/2867 on 13.03.2017 by CS (TIS)The cellular responses of Crenimugil labrosus and Pleuronectes platessa to tissue parasites have been investigated using metacercariae of Cryptocotyle lingua and Rhipidocotyle johnstonei, and the myxosporidjan Myxobolus exiguous. The study was based on fish naturally infected with the parasites, and in addition experimental infections of C. lingua were established in grey mullet. The most intense response was induced by R. -johnstonel in plaice, and was composed mainly of cells of the macrophage series, which included epithelioid and giant cells. Fibroblasts and collagen deposition formed the periphery of the lesion which was Interpreted as a granuloma. Eggs released by this progenetic metacercaria did not produce separate granulomata.