Summary
Ergasilus leoporindis n. sp. is described from an Amazonian fish called the "Aracu" (Anostomidae: Leporinus fasciatus (Bloch). The new species is similar to E. bryconis Thatcher. 1981. but it lacks the pectinate seta on the third segment of the first exopodite. Also, the new species is smaller, has a longer second antenna and the single projecting sensillus of this antenna is on the third segment and not on the second.