Dr. Éva Murai szerk.: Miscellanea Zoologica Hungarica 3. 1985 (Budapest, 1985)
Sulgostowska, T.; Giziewicz, J.: Influence of material extracted from Diploposthe laevis (Bloch) and D. bifaria (Siebold in Creplin) (Cestoda) on tapeworm Hymenolepis diminuta (Rudolphi) in rats
Influence of material extracted from Diploposthe laevis (Bloch) and D. bifaria (Siebold in Creplin) (Cestoda) on tapeworm Hymenolepis diminuta (Rudolphi) in rats By T. SULGOSTOWSKA* & J. GIZIEWICZ (Received 15 February, 1985) ABSTRACT. Interspecific relationships in tapeworms were investigated. Acetoneextracted oil (AEO) and post-acetone water extracts (WE) were prepared from the worms Diploposthe laevis (Bloch, 1782) and D. bifaria (Siebold in Creplin, 1846), collected from the ducks Aythya ferina (L. ) and A. nyroca (Güld. ) These materials were intragastrically administered to Wistar rats, which had earlier been experimentally infected with the tapeworm Hymenolepis diminuta (Rudolphi, 1819). The rats were sacrificed and the behaviour of H. diminuta in the intestine was observed in order to determine its reaction to the worm extracts. For comparison, the behaviour of H. diminuta in infected, bat untreated, rats was examined. It was found that AEO exerted a toxic effect on H. diminuta, whereas WE showed no activity. Analogous materials prepared from random species of tapeworms collected from the duck genus Anas had no effect on H. diminuta. According to studies on the duck genus Aythya (SULGOSTOWSKA, 1976, 1977), several parasite species occur in the intestine of young A. ferina (L. ) and A. nyroca (Güld.) as early as in other ducks. However, if by any chance in this intestine the tapeworms Diploposthe laevis (Bloch, 1782) or D. bifaria (Siebold in Creplin, 1846) are present, then with the development of the host only one of these species becomes dominant (in A. ferina mainly D. laevis and in A. nyroca mainly D. bifaria ). Thus there is an elimination of other parasite populations, as well as of the "superfluous" individuals of its own population, when only two or occasionally three individuals are left. The ecological causes of this phenomenon include the ability of the population of these tapeworms to dominate the worm community. This paper presents some experimental results which indicate that biochemical factors may also be involved in this phenomenon. MATERIALS AND METHODS Preparation of acetone-extracted oil (AEO) from tapeworms D. laevis and D. bifaria (collected in Poland and in Hungary). The abovementioned tapeworms were isolated from the alimentary tract of A. ferina and A. nyroca , washed from intestinal contents with water and placed in vials with about 5 ml of acetone. This material was kept at room temperature for 4 months. After completion of this extraction period, the tapeworms were removed, rinsed with pure acetone, and dried to constant weight in a dessicator under vacuum, at room temperature. The combined acetone extract and washings were evaporated under vacuum at 40°C, yielding a pale-yellow oil. This oil was dissolved in 50 ml of anhydrous ethanol; ethanol was evaporated and the oil was dried in a dessicator under vacuum, over P O The oil was soluble in ethanol and chloroform. * Part of the preparation of this work was done by the senior author during her visit to Hungary in 1983.
