CYPRIA-REPTANS (CRUSTACEA, OSTRACODA) AS AN INTERMEDIATE HOST OF NEOECHINORHYNCHUS-RUTILI (ACANTHOCEPHALA, EOACANTHOCEPHALA) IN ITALY

A total of 2,568 specimens of 3 species of ostracod, namely Herpetocyp ris sp., Ilyocypris sp., and Cypria reptans Brohnstein, 1928, was coll ected between November 1994 and April 1995 from the Ceresina Canal, a tributary of the River Brenta (northern Italy), and examined for larva l helminths. Larvae of Neoechinorhynchus rufili Muller, 1780 were foun d in the hemocoel of C. reptans. The prevalence of infection ranged fr om 8.57 to 14.51%. Most larvae were in the cystacanth stage (a new geo graphical record for this cystacanth). Not more than 3 larvae were enc ountered in a single host. Among 48 aquatic alder fly larvae of Sialis lutaria collected over 6 mo, together with the crustacean, no infecte d larvae were encountered. Specimens of Gasterosteus aculeatus (Pisces : Gasterosteiformis) collected with the arthropods from the same site were found to be parasitized with adult N. rutili. Fish stomach conten t analysis showed ostracods to be a major food item of three-spined st icklebacks in the study area during much of the year.