Gasterosteus
Gasterosteus microcephalus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Scorpaeniformes
Family:	Gasterosteidae
Genus:	Gasterosteus Linnaeus, 1758
Type species
Gasterosteus aculeatus Linnaeus, 1758
Synonyms
Obolarius Tilesius, 1811 Gasteracanthus Pallas, 1814 Leiurus Swainson, 1839 Gladiunculus Jordan & Evermann, 1927

Gasterosteus is a genus of ray-finned fishes belonging to the family Gasterosteidae, the sticklebacks. These fishes are found in freshwater, brackish water and marine habitats in the Holarctic region.

Species

There are currently 6 recognized species in this genus:

• Gasterosteus aculeatus Linnaeus, 1758 (Three-spined stickleback)
• †Gasterosteus crenobiontus Băcescu & R. Mayer, 1956 (Techirghiol stickleback)
• Gasterosteus islandicus Sauvage, 1874 (Iceland stickleback)
• Gasterosteus microcephalus Girard, 1854 (Smallhead stickleback)
• Gasterosteus nipponicus Higuchi, Sakai & A. Goto, 2014 ^[1]
• Gasterosteus wheatlandi Putnam, 1867 (Black-spotted stickleback)

Additionally there are a number of fossil species including:

• †Gasterosteus kamoensis Nazarkin, Yabumoto & Urabe, 2013