Ctenogobius smaragdus (Valenciennes, 1837) .

Emerald Goby; Gobio Esmeralda, Esmeralda Cabezona.

Distribution: Global: Western Atlantic Ocean; from South Carolina, USA, to Pernambuco, Brazil; entering estuaries and littoral lagoons and ascending river courses; Costa Rica: To (Atlantic), 0–4 m.a.s.l., Per, Dia.

Occurrence and conservation status: Nat, LC.

References: Angulo et al. (2013: 1008; listed, including taxonomic information and distributional data) and Robertson & Van Tassell (2019: 4132; detailed description, including illustrations, information on distribution, with a map, and ecology).