aestuarius, Acentrogobius Smith [J. L. B.] 1959:202, Fig. 18 [Ichthyological Bulletin, Department of Ichthyology, Rhodes University No. 13; ref. 4122] Inhambane, Mozambique. Holotype: SAIAB [formerly RUSI] 215. Paratypes: SAIAB [formerly RUSI] 871 (1). •Valid as Istiogobius aestuarius (Smith 1959) -- (Goren 1981:98 [ref. 8597]). •Synonym of Istigobius spence (Smith 1947) -- (Murdy & Hoese 1985:27 [ref. 5237], Hoese 1986:794 [ref. 5670], Maugé 1986:375 [ref. 6218], Fricke & Kulbicki 2006:351 [ref. 28867], Fricke et al. 2018:334 [ref. 35805], Parenti 2021:189 [ref. 38603], Larson 2022:112 [ref. 39971]). Current status: Synonym of Istigobius spence (Smith 1947). Gobiidae: Gobiinae. Habitat: brackish, marine.