iota, Hemigrammus Durbin [M. L.] 1909:60 [Annals of the Carnegie Museum v. 6 (no. 1); ref. 1166] Gluck Island, Guyana. Holotype: FMNH 53034 [ex CM 1458]. Paratypes: (11) BMNH 1911.10.31.393 (1); CAS 44417 [ex IU 11913] (2), 44418 [ex IU 11914] (1); FMNH 7347 (1), 53035-36 (2, 1); MCZ 29975 [ex CM] (1); SU 21917 (1). Type catalog: Henn 1928:65 [ref. 12305], Böhlke 1953:24 [ref. 12291], Ibarra & Stewart 1987:44 [ref. 12367]. •Valid as Hemigrammus iota Durbin 1909 -- (Lima & Oyakawa in Reis et al. 2003:132 [ref. 27061], Bertaco & Carvalho 2005:147 [ref. 28675], DoNascimiento et al. 2017:[8] [ref. 35679], Taphorn et al. 2022:15 [ref. 41297]). Current status: Valid as Hemigrammus iota Durbin 1909. Acestrorhamphidae: Pristellinae. Distribution: South America: Essequibo River basin (Guyana) endemic. Habitat: freshwater.