a mussel is a kind of water animal
mussel is shellfish. zebra_mussel is freshwater_mussel. swan_mussel is mussel. freshwater_mussel is mussel. freshwater_pearl_mussel is mollusca. marine_mussel is mussel. edible_mussel is marine_mussel. mussel is mollusc. mussel is clam. pearly_shelled_mussel is freshwater_mussel.