Tapeworms morphological changeability in the chain of Hymenolepis diminuta WMS "strain" generations

The investigations covered 54 subsequent generations of Hymenolepis diminuta WMS "strain" obtained through the administration of 6 cysticercoids of tapeworm to Wistar strain rats and WAG alb. rats. The number of tapeworms at 2.5 months after the infection of rats ranged from 3 to 6, on the average 5.2. Taking into consideration the most important type 1p2a (one testis on the poral side and two testes on the aporal side), 0p3a, 1p3a and 2p1a proglottids a significant differences was found in the distribution of the numerousity of type 1p3a proglottids (P < 0.05). This indicates a possibility of an unguided change of the number of proglottids of this type in a period covering 54 subsequent H. diminuta generations bred in laboratory conditions.