mahdiaensis, Rivulus Suijker [W. H.] & Collier [G. E.] 2006:3, Figs. 1-3 [Zootaxa No. 1246; ref. 28729] Blackwater creek, tributary of Potaro River, on 5 miles from Mahdia crossing the road from Mahdia to Garroway Stream, 5°21'11'N, 59°08'48"W, Mazaruni-Potaro District, Guyana. Holotype: ZMA 123720. Paratypes: FMNH 113582-84 (1, 1, 1); ZMA 123721 (1), 123722 (1), 123853-55 (1, 1, 1). Combined with a neuter genus, the adjective should be mahdianense. •Valid as Rivulus mahdiaensis Suijker & Collier 2006 -- (Costa & Souza 2009:64 [ref. 30289], Schindler & Valdesalici 2011:109 [ref. 31382]). •Valid as Laimosemion mahdiaense (Suijker & Collier 2006) -- (Costa 2011:239 [ref. 31655] as mahdianensis, Vermeulen et al. 2012:188 [ref. 32253] as mahdianensis, Costa & Lazzarotto 2014:372 [ref. 33247] as mahdianensis, Valdesalici 2016:279 [ref. 34270] as mahdianensis, Taphorn et al. 2022:37 [ref. 41297]). Current status: Valid as Laimosemion mahdiaense (Suijker & Collier 2006). Rivulidae: Rivulinae. Distribution: South America: Mazaruni-Potaro District (Guyana) endemic. Habitat: freshwater.