breviceps, Rivulus Eigenmann [C. H.] 1909:49 [Annals of the Carnegie Museum v. 6 (no. 1); ref. 1222] Shrimp Creek, near Kaituer, Guyana. Holotype: FMNH 52710 [ex CM 1075]. Paratypes: (4, CM and IU) BMNH 1911.10.31.531 (1), CAS 44211 [ex IU 11758] (3). Type catalog: Henn 1928:86 [ref. 12305], Ibarra & Stewart 1987:76 [ref. 12367], Huber 1992 [ref. 20639]. •Valid as Rivulus breviceps Eigenmann 1909 -- (Huber 1992:133 [ref. 20639], Vermeulen & Isbrücker 2000:190 [ref. 25219], Lazara 2001:271 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061], Hrbek et al. 2004:573 [ref. 27910], Suijker & Collier 2006:10 [ref. 28729], Costa 2006:152 [ref. 28875] in subgenus Laimosemion). •Valid as Laimosemion breviceps (Eigenmann 1909) -- (Costa 2011:239 [ref. 31655], Vermeulen et al. 2012:187 [ref. 32253], Taphorn et al. 2022:36 [ref. 41297]). Current status: Valid as Laimosemion breviceps (Eigenmann 1909). Rivulidae: Rivulinae. Distribution: South America: Amazon River basin (Guyana) endemic. Habitat: freshwater.