Pairing of schistosoma mansoni males in infected Syrian hamsters

ABSTRACT

Pairing of male schistosomes in the liver of infected hamsters was recorded with Egyptian S. mansoni strain. The homospecific male pairs never carried each other in the gynecophoric duct, but they are closed in either central or hepatic veins. Other perfused males and females en copula showed normal mating behavior. The paired males were more or less in the same size. The random sexed miracidia used resulted in obtaining 1 2.1 female/male ratio. It is concluded that the random increase of male schistosomes may create the male pairing behavior. Also, the migration of female against the blood stream to the mesenteric plexus of the host and the failure of male to catch them may lead to this homosexual pairing. The black hemozoin- like substance seen in mature females was also observed in the pairing males and this probably reflects the effect of scarcity or migration of females to the mesenteric plexus