The genus Zuzalpheus Ríos and Duffy, 2007 was established for species of the presumably monophyletic Synalpheus gambarelloides species group of the second-most speciose alpheid genus, Synalpheus Bate, 1888. However, the validity of Zuzalpheus as a distinct genus is questionnable. First, Zuzalpheus is embedded within Synalpheus in a previously published phylogeny of Synalpheus based on molecular and morphological data, making Synalpheus paraphyletic. Secondly, the three morphological characters used by Ríos and Duffy (2007) to distinguish these two genera are minor compared to distinctions among other alpheid genera; only two of these characters can be considered valid, and only tentatively so. Therefore, Zuzalpheus is synonimized with Synalpheus. However, Zuzalpheus does remain an available name, which could be used in a future subgeneric classification based on a comprehensive phylogenetic assessment of Synalpheus.