Paratypes of Oligogonotylus andinus sp. nov.; adults at different degrees of maturity A specimen in partly lateral orientation with the first eggs in utero; gonotyls were not observed B, D–F specimens with the seminal receptacle visible (left on B and F, right on E and D) and four gonotyls A, C, D, F specimens with the vitelline duct visible A, D, E specimens with the seminal vesicle dorsal to the ventral sucker. Scale bars: 100 μm (A–F).