Trichodina pediculus can often be found gliding like a hovercraft along the tentacles of the freshwater polyp Hydra. Note the nematocysts (stings) on this Hydra tentacle. Although the name pediculus (louse) could imply this is a parasite it does not feed on the host. It feeds on detritus, bacteria and algae.

See the underside of Trichodina.

Part of the Collection of the Ciliate Centre of the Micropolitan Museum © Wim van Egmond