Transplantation of the trematode Philophthalmus hegeneri to new and altered sites

Abstract

Six of 10 juvenile eye flukes, Philophthalmus hegeneri Penner and Fried 1963 homotransplanted into chicks' eyes survived, grew, and developed. Two flukes that developed in the same eye of a chick appeared fertile. The other 4 flukes developed individually in chicks' eyes and were infertile. The absence of live flukes implanted into the coeloms of chicks indicated an incompatibility of this site. Flukes implanted into the cloacas of chicks showed no signs of growth or development and were dead by the third day postimplantation. Sixteen of 25 juvenile flukes transplanted into chicks' eyes lacking nictitating membranes survived, grew, and developed on the sciera, cornea, and eyelids. Four flukes migrated to intact eyes and developed on the normal site, the interior surface of the nictitating membrane. They were larger than worms that remained in altered eyes. Twenty-three of 120 metacercariae inoculated into the median slits of 7 chicks lacking both nictitating membranes survived, grew, and developed in the altered eyes. Since fertile worms were not recovered from eyes lacking nictitating membranes, the possibility exists that the physicochemical requirements of sexually mature eye flukes differ from those of juvenile flukes.