On Schistosoma margrebowiei Le Roux, 1933: the morphology of the egg, miracidium and cercaria, the compatibility with species of Bulinus, and development in Mesocricetus auratus

Abstract

The morphology of the egg, miracidium, and cercaria of Schistosoma margrebowiei are described. The compatibility of S. margrebowiei with species of Bulinus has been examined. The parasite develops well in the diploid, tetraploid and octoploid snails of the truncatus/tropicus complex with overall infection rates of 38.1%, 30.1% and 29.1% respectively, and in reticulatus group snails (Bulinus wrighti) with an infection rate of 45.8% of those snails surviving the prepatent period. Only two species of the forskali complex (Bulinus bavayi, Aldabra; Bulinus beccarii, South Arabia) are slightly compatible, and snails of the africanus group are incompatible. The overall worm return from 24 hamsters exposed individually to 100 cercariae was 39.8%; 82.1% of the worms were paired, the remainder unpaired. The growth of the paired worms was recorded from 28-60 days. The prepatent period in hamsters in 33 days, in sheep 38 days. The mean egg production was 837 eggs/day in infections ranging from 33 to 60 days. Most eggs (80.9%) were deposited in the intestine, and only 18.2% were deposited in the liver. The parasite is pathogenic in hamsters, and peak death rate occurred in the 50-60 day group infections which coincided with the period of peak egg production.