OBSERVATIONS ON THE DEVELOPMENT OF SYNCUARIA-SQUAMATA (NEMATODA, ACUARIIDAE), A PARASITE OF CORMORANTS, IN THE INTERMEDIATE AND PARATENIC HOSTS

The development of the nematode Syncuaria squamata (Linstow, 1883), a gizzard parasite of cormorants, was experimentally studied in the ostr acod Notodromas monacha. After the eggs of this nematode have been swa llowed by the ostracod, the toothed first-stage larvae of the parasite are released and penetrate through the intestinal wall into the haemo coel of the crustacean. Before attaining the infective third stage, th e larvae moult twice in the body of the intermediate host (9-11 and 13 -15 days after infection at water temperatures of 20-22 degrees C). Th e fishes Alburnoides bipunctatus, Noemacheilus barbatulus, Oncorhynchu s mykiss and Poecilia reticulata were for the first time recorded as s uitable experimental paratenic hosts of S. squamata third-stage larvae in which a slight growth of larvae may occur. The first recorded natu ral paratenic host of this nematode was tench, Tinca tinca, originatin g from a South-Bohemian pond where cormorants occur. Paratenic hosts a re apparently the main source of S. squamata infection for cormorants.