Studies of actinosporean myxozoan stages parasitic in oligochaetes from the sediments of a hatchery where atlantic salmon harbour Sphaerospora truttae infection

Abstract

Five different myxozoan actinosporean spore forms of 4 collective groups are described from oligochaete worms obtained from the sediments of a Scottish salmon hatchery where Sphaerospore truttae infections recur annually. Synactinomyxon 'A', synactinomyxon 'B', raabeia, triactinomyxon and aurantiactinomyxon stages are illustrated, characterised and the stimuli for their polar filament release investigated. Each actinosporean is compared with actinosporean 'species' described in the literature and actinosporean stages described from reports of 2 host myxozoan hie cycles. Three of the forms reported appear to be previously undescribed.