audax, Acentrogobius Smith [J. L. B.] 1959:201, Fig. 17 [Ichthyological Bulletin, Department of Ichthyology, Rhodes University No. 13; ref. 4122] Ibo Island, Mozambique, western Indian Ocean. Holotype (unique): SAIAB [formerly RUSI] 192. •Synonym of Acentrogobius madraspatensis (Day 1868) -- (Allen 2015:7 [ref. 33699] if valid). •Synonym of Acentrogobius viganensis (Steindachner 1893) and Acentrogobius madraspatensis (Day 1868) -- (Allen 2017:110 [ref. 35601]). •Valid as Acentrogobius audax Smith 1959 -- (Akihito in Masuda et al. 1984:249 [ref. 6441], Hoese 1986:777 [ref. 5670], Nakabo 2000:1244 [ref. 25182], Larson & Murdy 2001:3594 [ref. 26293], Sakai et al. 2001:108 [ref. 25693], Nakabo 2002:1244 [ref. 26193], Motomura et al. 2010:202 [ref. 31256], Fricke et al. 2018:322 [ref. 35805], Parenti 2021:78 [ref. 38603], Furuhashi et al. 2023:27 [ref. 40140]). •Valid as Yongeichthys audax (Smith 1959), possibly a junior synonym of Yongeichthys viganensis (Steindachner 1893) -- (Larson 2022:155 [ref. 39971]). Current status: Valid as Yongeichthys audax (Smith 1959). Gobiidae: Gobiinae. Distribution: Western Indian Ocean: KwaZulu-Natal (South Africa) and Mozambique to Seychelles and Madagascar; northwestern Pacific: Osumi Islands (Japan). Habitat: brackish, marine.