Acyrtus Schultz [L. P.] 1944:56 Masc. Sicyases rubiginosus Poey 1868. Type by original designation (also monotypic). Acyrtus and Arcos were described in the same work. •Synonym of Arcos Schultz 1944 based on placement of the type species -- (Böhlke & Chaplin 1968:707 [ref. 23150]). •Valid as Acyrtus Schultz 1944 -- (Briggs 1955:125 [ref. 637], McEachran 2003:1774 [ref. 27089], Sampaio et al. 2004:205 [ref. 27998], Conway et al. 2014:1 [ref. 33313], Conway et al. 2020:889 [ref. 38030] in Gobiesocinae, Tavera et al. 2021:1 [ref. 38564], Quintão et al. 2022:1 [ref. 39696]). Current status: Valid as Acyrtus Schultz 1944. Gobiesocidae: Gobiesocinae.