DEVELOPMENT OF ACCESSORY SEXUAL ORGANS IN BIOMPHALARIA-GLABRATA (PLANORBIDAE) IN RELATION TO TIMING OF INFECTION BY SCHISTOSOMA-MANSONI - CONSEQUENCES FOR ENERGY-UTILIZATION PATTERNS BY THE PARASITE
A. Theron et C. Gerard, DEVELOPMENT OF ACCESSORY SEXUAL ORGANS IN BIOMPHALARIA-GLABRATA (PLANORBIDAE) IN RELATION TO TIMING OF INFECTION BY SCHISTOSOMA-MANSONI - CONSEQUENCES FOR ENERGY-UTILIZATION PATTERNS BY THE PARASITE, Journal of molluscan studies, 60, 1994, pp. 25-31
The growth rates of ovotestis and individual accessory sexual organs (
ASO) of Biomphalaria glabrata snails were studied for controls and for
immature and mature snails infected with Schistosoma mansoni. The inf
ection of immature B. glabrata strongly delays growth of the ovotestis
and inhibits the development of the accessory sexual organs. There is
no significant difference up to 2 weeks post infection in the volume
of the ovotestis and the ASO between mature infected B. glabrata and c
ontrol snails. From 3 to 4 weeks post infection there was a reduction
in the volume of the ovotestis and the ASO of infected mature B. glabr
ata; then growth of the ovotestis, albumen gland and female organs was
stopped, but the effect of infection was less consistent for the male
organs. For a parasite, immature and mature snails have to be conside
red as two different resource environments, each having at infection t
ime a particular pattern of resource allocation, towards growth for ju
venile and towards reproduction for adult snails, changing the possibl
e energy utilization patterns which can be used by the trematode.