PATTERN OF INFECTION OF GAMMARUS-AEQUICAUDA (AMPHIPODA) WITH METACERCARIAE OF LEVINSENIELLA-TRIDIGITATA (TREMATODA, MICROPHALLIDAE)

We investigated the pattern of infection of Gammarus aequicauda (Amphi poda) with metacercariae of Levinseniella tridigitata (Trematoda: Micr ophallidae) in a natural lagoon. Prevalence was significantly higher i n females than in males, whereas there was no difference between sexes in parasitic intensity. Despite the very large size of L. tridigitata metacercariae, the mean abundance increased with host size and in bot h sexes, suggesting that the accumulation of this parasite has no sign ificant effect on host survival. Levinseniella tridigitata is known no t to alter its host's behavior. Our results contrast with those obtain ed with other helminths that alter host behavior in order to favor the ir transmission to the definitive host.