A migratory Anadromous species ( Fish who live at sea but return to the river to Spawn ) from the South of Ireland, where the River Barrow, Co Carlow hold a population of both Alis Or Greater Shad Known as Twaite Shad ( think  Giant herring with as many bones… but an exceptional high oil content, making it delicious . A really popular and greatly prized in the South West of France as the Alose