Turbellarians are mostly free living in marine, fresh water or moist terrestrial habitats. They are benthic scavengers living on or beneath stones, gliding over the substrate with the cilia, which cover their bodies. They secrete mucus, which helps them glide and trap their prey. Some swim with undulating movements of the body. Turbellarians lay eggs that generally hatch into a juvenile worm. Some have a brief freeliving stage called Muller’s larva, which metamorphoses into a juvenile worm.
From left to right:
Yungia aurantiaca, Thysanozozon brocchii from Naples, Geoplana spenceri, an Australian land planarian.