Production and reproduction in Hymenolepis diminuta (Platyhelminthes: Cestoda)

Abstract

The productive and reproductive capacities of the tapeworm Hymenolepis diminuta were examined at five densities of infection, in two strains of rat host, bred and weaned in two facilities and maintained on two different diets.Density of worm infection and host diet significantly affected worm growth. Total egg production by the worms increased with density of infection, but decreased for individual worms. Reduced egg production was a function of both reduced worm proglottid production and a decrease in eggs per proglottid. Energy content increased from the immature through the gravid regions of the worms.Total net worm production increased with density of infection with a matching decrease in individual production. Approximately 80% of net production was put into reproduction. Biomass turnover rate remained relatively constant over all levels of infection.Comparison with similar data from free-living helminths indicates that the enormous differential in egg production rates of individual worms can largely be accounted for by the differences in relative body and egg sizes.