Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
     Pisces
       Class Actinopterygii Woodward, 1891 - ray-finned fishes
         Order Gasterosteiformes Gill, 1872 - sticklebacks
           Family Gasterosteidae Günther, 1859 - sticklebacks
           Family Hypoptychidae - sand-eels
           Family Indostomidae
           Family Pegasidae - seamoths