a freshwater mussel is a kind of mussel
mussel is shellfish. zebra_mussel is freshwater_mussel. thin_shelled_mussel is freshwater_mussel. swan_mussel is mussel. freshwater_pearl_mussel is mollusca. freshwater_mussel is mussel. mussel is mollusk. marine_mussel is mussel. edible_mussel is marine_mussel. pearly_shelled_mussel is freshwater_mussel.