Surface morphology of Nicolla skrjabini (Trematoda: Opecoelidae), a common parasite of European freshwater fishes, as revealed by SEM.

Scanning electron examination of trematode specimens belonging to Nicolla skrjabini (Iwanitzky 1928), collected from brown trout Salmo trutta fario L. in the Czech Republic, made it possible to study their surface morphology including details not described previously. The tegument bears numerous characteristic papillae mainly around and inside the suckers and around the genital pore and minute sensory organs near the anterior body end. Surface morphology may prove to be useful in distinguishing Nicolla spp.