Gasterosteiformes

Gasterosteoidei is a suborder of ray-finned fishes that includes the sticklebacks and relatives. It belongs to the order Perciformes.

== Systematics == Gasterosteoidei is treated as a suborder within the order Scorpaeniformes in the 5th edition of Fishes of the World, but in other phylogenetic classifications it is treated as the infraorder Gasterosteales within the suborder Cottoidei or as a sister clade to the Zoarcales in the order Zoarciformes. Indostomidae is included within Gasterosteoidei in Fishes of the World' but according to Betancur et al. its inclusion in the clade renders it paraphyletic and they classify that family within the monotypic suborder Indostomoidei within the Synbranchiformes.