cayennensis, Hemigrammus unilineatus Géry [J.] 1959:248, Fig. 1 [Bulletin Mensuel de la Société Linnéenne de Lyon v. 28 (no. 8); ref. 10038] Small freshwater stream on Cayenne Island, French Guiana. Holotype: MHNG 2179.061. Paratypes: (10) ANSP 94715 (1), SMF 5385 (1), USNM 179757 (2), ZMA 101049 (1). Type catalog: Nijssen et al. 1982:19 [ref. 19236], Böhlke 1984:44 [ref. 13621], Vari & Howe 1991:25 [ref. 19022], Weber 1998:7 [ref. 32707]. •Valid as Hemigrammus cayennensis Géry 1959 -- (Géry et al. 1991:59 [ref. 21021]). •Synonym of Hemigrammus unilineatus (Gill 1858), but a valid subspecies -- (Planquette et al. 1996:282 [ref. 22818]). •Synonym of Hemigrammus unilineatus (Gill 1858) -- (Weitzman & Palmer 1997:237 [ref. 22743], Lima & Oyakawa in Reis et al. 2003:134 [ref. 27061], Carvalho et al. 2017:12 [ref. 35509]). Current status: Synonym of Hemigrammus unilineatus (Gill 1858). Characidae: Stethaprioninae. Habitat: freshwater.