Maturation of Paramphistomum cervi in sheep in India

Histological studies of the trematode Paramphistomum cervi collected throughout the year from the rumen of sheep, revealed the occurrence of gravid worms from April to August and immature worms from September to March. The maturation of the gonads and the accessory sex glands i.e., the prostate-, Mehli's- and vitelline-gland began during the period March-April and showed functional peaks during the period July-August, which coincided with the availability of the intermediate host, Indoplanorbis exustus in nature. Maturation as well as the incidence of infection of P. cervi have also been discussed in relation to various ecological factors, i.e., rainfall and temperature.