microcephalus, Gasterosteus Girard [C. F.] 1854:133 [Proceedings of the Academy of Natural Sciences of Philadelphia v. 7; ref. 1817] Tule Lake, San Joaquin Valley, California, U.S.A. Syntypes: ANSP 14275-87 (13), 14288-89 (2, missing); MNHN 0000-0302 [ex USNM] (1); UMMZ 146720 (4). Type catalog: Bertin & Estève 1950:36 [ref. 19576], Böhlke 1984:103 [ref. 13621]. •Valid as Gasterosteus microcephalus Girard 1854 -- (Herrera 1896:38 [ref. 39336], Okada 1961:612 [ref. 6363], Nakabo 2000:513 [ref. 25086], Mecklenburg et al. 2002:333 [ref. 25968]). •Synonym of Gaserosteus aculeatus Linnaeus 1758, but a valid subspecies microcephalus Girard 1854 -- (Kuroda 1953:277 [ref. 39545], Ida in Masuda et al. 1984:83 [ref. 6441], Swift et al. 1993:123 [ref. 22379], Castro-Aguirre et al. 1999:226 [ref. 24550], Ruiz-Campos et al. 2000:71 [ref. 24940], Moyle 2002:340 [ref. 26449], Miller 2006:320 [ref. 28615], Scharpf 2007:35 [ref. 30398]). •Synonym of Gasterosteus aculeatus Linnaeus 1758 -- (Berg 1949:973 [ref. 20662], Monod 1973:282 [ref. 7193], Denys et al. 2022:397 [ref. 40085]). Current status: Synonym of Gasterosteus aculeatus Linnaeus 1758. Gasterosteidae. Habitat: freshwater, brackish, marine.