Infection Dynamics of Schistocephalus Solidus (muller, 1776), in Three-spined Stickleback, Gasterosteus Aculeatus L. in Airthrey Loch, Scotland

ABSTRACT Infection of Schistocephalus solidus in three-spined stickleback, Gasterosteus aculeatus was investigated for over a two year period from Airthrey Loch, Scotland. Altogether 1301 fishes were sampled. A total of 1327 S. solidus plerocercoid worms were extracted from the visceral cavity of 385 fish. The prevalence was 29.55%, mean intensity (3.44) and abundance (1.01). Monthly prevalence and abundance showed significant difference in two years. Infection in female (14.68%) was higher than male fish (5.99%). The highest infection was recorded in autumn and spring. There are two waves of infection, the first wave operates from July to October and second starts in February and ends in June. The growth of S. Solidus in the fish is influenced by a rise in water temperature in summer. In natural environment, probably different biotic and abiotic factors may affect the transmission of S. solidus and thus may affect the prevalence and intensity of infection. Such factors could influence the survival of coracidia, or abundance of suitable copepod at a given time. The growth of plerocercoid in the fish host may be influenced by factors both internal and external to the fish host. It is concluded that S. solidus was moderately established in second intermediate host G. aculeatus in Airthrey Loch