tetranemus, Hybopsis Gilbert [C. H.] 1886:208 [Bulletin of the Washburn Laboratory of Natural History v. 1 (no. 7); ref. 17815] Elm and Spring Creeks, near Medicine Lodge, Barber County, Kansas, U.S.A. Syntypes: (8) whereabouts unknown. Type catalog: Gilbert 1998:155 [ref. 23395]. •Synonym of Hybopsis aestivalis (Girard 1856) -- (Lee et al. 1980:180 [ref. 22416]). •Synonym of Hybopsis aestivalis (Girard 1856), but possibly valid subspecies or species -- (Robison & Buchanan 1988:182 [ref. 23393]). •Synonym of Extrarius aestivalis (Girard 1856), but a valid subspecies -- (Cross & Collins 1995:62 [ref. 23394]). •Valid as Macrhybopsis tetranema (Gilbert 1886) -- (Gilbert 1998:155 [ref. 23395], Eisenhour 1999:974 [ref. 24184], Luttrell et al. 1999:981 [ref. 24185], Underwood et al. 2003:493 [ref. 27126], Nelson et al. 2004:73 [ref. 27807], Eisenhour 2004:9 [ref. 29854], Scharpf 2005:24 [ref. 28940], Page & Burr 2011:213 [ref. 31215], Page et al. 2013:73 [ref. 32708], Gilbert et al. 2017:501 [ref. 35222], Echelle et al. 2018:546 [ref. 35765], Page et al. 2023:72 [ref. 40505]). Current status: Valid as Macrhybopsis tetranema (Gilbert 1886). Leuciscidae: Pogonichthyinae. Distribution: North America: Arkansas River basin (southern-central U.S.A.). Habitat: freshwater.