in taxon sea thong Himanthalia elongata is a brown alga in the order *Fucales*, also known by the common names thongweed, sea thong and sea spaghetti. It is found in the north east Atlantic Ocean and the North Sea. According to the World Register of Marine Species, *Himanthalia elongata* is the only member of its genus, *Himanthalia* Lyngbye, 1819 [2] and the only member of its family, *Himanthaliaceae* (Kjellman) De Toni, 1891. sea spaghetti thong weed wracks Himanthalia elongata requires discussion