The present work morphologically characterizes Paratrichodina africana from the gills of wild and farmed Nile
tilapia from Northern Brazil (eastern Amazonia). Ninety fish were captured for parasitological analysis in Macapá, State
of Amapá, from a wetland area bathed by the Amazon River commonly called ‘Ressaca do Zerão’ (n = 52), as well as
from a local fish farm (n = 38). Wet smears of the skin and gills of the captured fish were air dried at room temperature
and impregnated with silver nitrate by Klein’s method for posterior examination of the adhesive disc structures.
Total prevalence of parasitism was 16.6% (23% in fish from wetland and 7.8% in farmed fish). Characterized as a
small-sized trichodinid, it presented the following measures: 33.2 ± 4.7 µm body diameter, 17.5 ± 2.1 µm adhesive
disc, 10.0 ± 0.9 µm denticulate ring, and 22.6 ± 2.0 denticles. Paratrichodina africana reported in this study strongly
resembles those described for other localities, but it differs by presenting greater body length. This is the fourth report
of P. africana parasitizing a host fish.