clam worm nereis sp. moving on beach in county donegal - irfeland

acron animal animalia annelid annelida anterior body color coloration dioecious donegal dorsal errantia examination fauna flexible ireland locomotion macro marine nereididae nereis ocean parapodia parapodium polychaeta polychaete posterior ragworm research sandworm science sea setae species study swim ventral vivid water worm zoology