In addition to A. islandica, a number of Aulacoseira species have straight rows of mantle areolae (A. granulata A. canadensis, and A. crassipunctata). Aulacoseira granulata has coarser areolae and characteristic spines. Both A. canadensis and A. crassipunctata are even more coarse in valve and areolae. Aulacosira nivalis has shorter mantle height than A. islandica.