p6200012 freshwater planarian triclad flatworm, schmidtea polychroa, with its anterior end folded back cecp 2021

america animal aquatic benthic black british brown close closeup columbia creeks detail dugesiidae europe eyes eyespots fauna flat flatworm flatworms freshwater invertebrate isolated macro natural nature north photography planaria planarian platyhelminthes polychroa predator schmidtea spings streams triclad tricladida turbellaria uncommon unusual water white wild worm