[Campbell Biology P.743] A researcher discovers a new species of freshwater organism that mo... | Practice Question
A researcher discovers a new species of freshwater organism that moves by gliding along surfaces using cilia on its ventral side. It preys on smaller organisms and exhibits a more centralized nervous system than cnidarians, along with light-sensitive eyespots and chemosensory flaps on its head. Based on the provided text, to which group would this organism most likely be classified?
Explanation
The description perfectly matches that of planarians mentioned in the 'Free-Living Species' section: 'planarians prey on smaller animals or feed on dead animals. They move by using cilia on their ventral surface, gliding along a film of mucus they secrete. A planarian's head features a pair of light-sensitive eyespots as well as lateral flaps that function mainly to detect specific chemicals. The planarian nervous system is more complex and centralized than the nerve nets of cnidarians.' Planarians are classified under Rhabditophora.