Awaous transandeanus (Günther, 1861) .

Pacific River Goby; Chupapiedras, Lamearenas, Gobio, Gobio de Río del Pacífico.

Distribution: Global: North, Central and South America; from central Baja California Sur and Sonora, Mexico, to Tumbes, Peru, Pacific drainages; Costa Rica: Ni, Te, Be, Ba, Ta, Pi, Tr and Co (Pacific), 0– 120 m.a.s.l., Per, Dia (Cat).

Occurrence and conservation status: Nat, LC.

References: Bussing (1966: 237; listed, information on distribution), Bussing (1987: 234; 1998: 398; brief description, including illustrations and an identification key, information on distribution, with a map, and ecology) and Angulo et al. (2013: 1007; listed, including taxonomic information and distributional data).

Remarks: Based on molecular data, McMahan et al. (2021) suggested the presence of two different species under the name A. transandeanus . The limit of such species is the northern portion of the Costa Rican Pacific. Morphological studies are necessary to corroborate this.