These are hand selected tonna galea, Giant tun shells for sale for seashell d©cor, and for making seashell centerpieces as their wide mouth opening will accommodate a large arrangement. The giant tun, Tonna galea, shell is found in the Caribbean, Atlantic, Mediterranean and Indo-Pacific oceans.  Tonna galea shells or Tun shells are thinner and usually roomier than helmet shells.  Tonna galea shells are almost exclusively tropical and prefer deeper water and feed mainly on fish, sea urchins and crustaceans.