Sinucta muculata

Sinucta muculata is a water-dwelling animal found in the Indian Ocean off the coast of Mauritius.

Naturalist Gerald Durrell's 1977 observation of the creature runs thus:

"At first, I could not believe that these weird objects were alive. I thought they must be strange, dead strands of some deep-sea seaweed now washed into the shallows by the tide, to roll and undulate helplessly on the sand to the small movements of the sea. Closer inspection showed me that they were indeed alive, unlikely though it seemed. Sinucta muculata, as this strange creature is called, is really a sort of elongated tube, which sucks in water at one end and with it microscopic organisms, and expels the water at the other."