SINGLE-SPECIES INFECTIONS OF ECHINOSTOMA-CAPRONI CERCARIAE IN PULMONATE SNAILS AND CONCURRENT INFECTIONS OF ECHINOSTOMA-CAPRONI AND ECHINOSTOMA-TRIVOLVIS CERCARIAE IN BIOMPHALARIA-GLABRATA

Single-species infections of Echinostoma caproni cercariae in various pulmonate snails showed that a higher percentage of cercariae encysted successfully in Biomphalaria glabrata than in other snail species and that the percentage encystment was significantly greater in B. glabra ta than in either Helisoma trivolvis or Lymnaea elodes. There were sig nificant differences in cyst diameter, thickness of outer and inner cy sts, and diameter of excretory concretions between E. caproni and Echi nostoma trivolvis metacercariae. These morphological differences helpe d to distinguish each species of cyst in concurrent cercarial infectio ns of E. caproni and E. trivolvis in B. glabrata. Moreover, in concurr ent infections E. trivolvis localised only in the saccular kidney, whe reas E. caproni occurred in both the saccular kidney and the pericardi um. (C) 1998 Australian Society for Parasitology. Published by Elsevie r Science Ltd.