Phylogenetic relationships of the SSU-rRNA sequences of B. grimi marked in bold and other Trichostomatia species showing the position of B. grimi inferred by maximum likelihood method and Bayesian algorithm. The trees were rooted using the sequence of Nyctotheroides deslierresae as the outgroup taxa. Numbers at nodes indicate bootstrap percentage and posterior probability, respectively. The sequences corresponding to species of the genus Balantidium are shadowed.