Observations on non-random distribution of spores of Henneguya spp. (Cnidaria: Myxosporea: Myxobolidae) within plasmodia

Abstract

Species of the cnidarian genus Henneguya Thélohan, 1892 (Myxosporea: Myxobolidae) are histozoic parasites commonlyfound in freshwater and, more rarely, in marine fish. The development of these parasites in fish tissues includes the formation of plasmodiawithin which occurs the sporogony originating spores with two caudal processes, which are usually randomly distributed withinthe plasmodia. In this report the authors present some cases of non-random distribution of the spores of six species of Henneguya withintheir plasmodia. Two different patterns of non-random distribution were found based on a literature survey. These patterns and theirorigin are discussed. Apparently this non-random distribution of the spores is due to both internal and external factors.