Held in place by muscles of the mesocoel, this gas exchange and food collection organ is a U-shaped ridge around the mouth bearing ciliated tentacles.
Held in place by muscles of the mesocoel, this gas exchange and food collection organ is a U-shaped ridge around the mouth bearing ciliated tentacles. Bryozoans, or colonial moss animals, are the only ones that can completely (*) retract it, while Phoronid tube worms extend it from their chitonous tubes.  Also found in Pterobranchs and Brachiopods, for 10 points— name this horse- shoe shaped filtering organ of simple deuterostomes.
Held in place by muscles of the mesocoel, this gas exchange and food collection organ is a U-shaped ridge around the mouth bearing ciliated tentacles.
lophophore