Morphological and developmental studies of the snake trypanosome Trypanosoma hydrae Ayala, Atkinson, Vakalis, 1983 in experimentally infected hosts and in culture.

Trypanosoma hydrae from the broad-banded watersnake, Nerodia fasciata confluens, underwent development in the freshwater leech, Placobdella parasitica. Epimastigotes and transitional stages were present only in the crop and gastric caecum. Only one metacyclic form was observed. The potential of leeches as vectors is discussed. Two broad-banded watersnakes were infected by inoculation with culture forms of T. hydrae maintained on NNN medium. Parasitemias varied from 10(5)/ml to 10(6)/ml with dividing forms seen only rarely. A broad and a slender form of T. hydrae are described from the peripheral blood of a watersnake 7 months after an experimental infection.