STUDIES ON THE OCCURRENCE OF ACTINOSPOREAN STAGES OF MYXOSPOREANS IN LAKE BALATON, HUNGARY, WITH THE DESCRIPTION OF TRIACTINOMYXON, RAABEIAAND AURANTIACTINOMYXON TYPES

In the framework of a one-year survey, the actinosporean infection of the oligochaete fauna living in the mud and on the vegetation of Lake Balaton, Hungary was studied. A total of 10 types of actinospores were isolated from the oligochaetes Tubifex tubifex and Limnodrilus hoffme isteri collected during the survey, which could be classified into the triactinomyxon, raabeia and aurantiactinomyxon groups. The drawings d epicting the individual actinospore types are presented on a plate and their characteristic dimensions summarised in tables. The prevalence and seasonality of actinosporean infections observed in the two oligoc haete species are illustrated graphically. Infection by actinospores s howed pronounced seasonality. In the spring and summer the prevalence of triactinomyxon infection in T. tubifex exceeded 30 and 40%, respect ively, while in the autumn it dropped to 6%. In T, tubifex raabeia inf ection of 3% prevalence was detected only in the summer period. In L. hoffmeisteri the peak of aurantiactinomyxon, raabeia and triactinomyxo n infection occurred in the summer with a prevalence of 21, 10 and 8%, respectively. Actinosporean infection in the individual Oligochaeta s pecies showed higher prevalence values than had been reported in the l iterature, which fact may be explained by the novelty of the examinati on technique used. Four types of actinospores found in Lake Balaton ar e identical with the actinospores already described. It cannot be dete rmined with absolute certainty which stages of myxosporeans parasitic in Lake Balaton fishes are identical with the 10 actinospores describe d.