LIFE-CYCLE OF OLIGOGONOTYLUS-MANTERI (DIGENEA, CRYPTOGONIMIDAE), A PARASITE OF CICHLID FISHES IN SOUTHERN MEXICO

The life cycle of the cryptogonimid, Oligogonotylus manteri Watson,197 6, was studied under natural and experimental conditions. Field study showed that aquatic snails, Benthonella gaza (Prosobranchiata: Rissoid ae), were the first intermediate host and cichlid fish, Cichlasoma uro phthalmus, either the second intermediate or definitive hosts. Laborat ory-reared cichlids, Cichlasoma synspilum, were exposed to 0. manteri cercariae from naturally infected snails by placing them into water or force-feeding with remnants of snails harboring 0. manteri cercariae. The development of metacercariae in experimentally infected C. synspi lum was completed 6 days postexposure (DPE) at 22-24-degrees-C. Metace rcariae from the gills, fins, body surface, and intestinal walls of na turally infected C. urophthalmus and experimentally infected C. synspi lum were used to expose C. synspilum, Oreochromis niloticus (Cichlidae ), and Poecilia reticulata (Poecilidae). Adult worms were detected in C. synspilum 16 DPE at 22-24-degrees-C and juveniles only in 0. niloti cus and P. reticulata. Results of both feeding experiments and examina tion of naturally infected cichlid fish from the Yucatan Peninsula rev ealed that metacercariae previously reported as Echinochasmus zubedakh aname were 0. manteri.