Parasites of Salmo trutta L. from the Tirino River. Part IV. Intermediate hosts of Cyathocephalus truncatus (Pallas, 1781) and Dentitruncus truttae Sinzar, 1955

During studies on helminth parasites of brown trout (Salmo trutta L.) from the river Tirino (L'Aquila - Italy), the intermediate hosts of Cyathocephalus truncatus (Pallas, 1781) and Dentitruncus truttae Sinzar, 1955 have been searched for. A total of 15,444 amphipoda belonging to the following 3 species: Echinogammarus roco Karman, 1973, Echinogammarus tibaldii Pinkster and Stock, 1970, and Gammarus italicus Goedmakers and Pinkster, 1977, have been dissected. E. roco, E. tibaldii and G. italicus were found infected with procercoid of Cyathocephalus truncatus (new hosts record and first procercoid record in Italy). E. roco, E. tibaldii and G. italicus were found infected with acanthella and cystacanth of Dentitruncus truttae (first record of intermediate hosts). Accordingly the ecology of the cestod C. truncatus and of the acanthocephalan D. truttae in their intermediate hosts has been studied considering principally the incidence and the seasonal occurence of the parasites.