Infectivity of Trypanosoma murmanensis to leeches (Johanssonia sp.).

Abstract

Experiments were designed to test the infectivity of trypomastigotes of Trypanosoma murmanensis to leeches at intervals after metatrypomastigotes had initiated infections in marine fish. Infectivity was determined by the presence of developmental stages in recently emerged leeches (Johanssonia sp.) that had fed on experimentally infected fish. A total of 1235 leeches were used in this study. The results indicate that the three morphotypes can initiate infections in leeches. Moreover, some trypanosomes are infective at least 24 h after transmission (16 (67%) leeches became infected). Few leeches acquired infections after feeding on infected winter flounder (Pseudopleuronectes americanus) between 2 and 12 days and on a cod (Gadus morhua) 4–5 days, but all those which fed 7 through 93 day s on five species of marine teleosts became infected. Some of the leeches transmitted infections to uninfected cod. It is believed that the leeches which harboured no developmental stages might not have ingested trypanosomes.