Bathygobius lacertus

Common Name

Checkerboard Frillfin Goby

Year Described

Poey, 1860


Dorsal Fin: VI, I-9
Anal Fin: I, 8
Pectoral Fin: 18-20 (mode 19)
Caudal Rays: 17 upper, 15-16 lower lobe (all types)
Scale Rows: 38-42
Pre-dorsal Scales: 17-20

Body of typical shape for the gobies but robust. Eye medium sized; about equal to snout length. Upper jaw usually more than 11% of SL. Pectoral fin extends to rear margin of first dorsal. Upper 4 (rarely 3 or 5) pectoral rays separate from membrane; usually bifurcated. Pelvic fins fully fused into disk. Pelvic fins reach anus or just fall short. Caudal fin rounded. Body fully scaled with scales extending forward to level of pre-opercular margin.


Body pale brown with numerous darker brown longitudinal lines following scale rows. Two rows of 6-7 blotches along lower trunk run from pectoral fin to base of caudal fin. Blotches offset to form a checkerboard pattern. Head with numerous pale spots and random larger black blotches. A dark band under eye. First dorsal fin with longitudinal dark stripes. Second dorsal fin and caudal fin with brown spots. Anal fin plain with a dark margin. Pelvic fin pale with a darker tip. Pectoral fin uniform.


Maximum size to 74mm SL.


Shallow coastal waters, including intertidal pools, rocky beds on calm shorelines, and in mangrove lagoons. Can occur over hard or soft bottoms.


Scattered records in the Caribbean Sea (Fl. Keys, Bahamas, Lesser Antilles, and Mexico to Tobago) and also Bermuda.


Lima-Filho, P.A., R. de Souza Rosa, A.D.S. de Souza, G.W.W.F. da Costa, C. de Oliveira, & W.F. Molina. 2016. Evolutionary diversification of Western Atlantic Bathygobius species based on cytogenetic, morphologic and DNA barcode data. Reviews in Fish Biology and Fisheries: 26(1), 109-121.

Tornabene, L., C. Baldwin, L.A. Weigt, and F. Pezold. 2010. Exploring the diversity of western Atlantic Bathygobius (Teleostei: Gobiidae) with cytochrome c oxidase-I, with descriptions of two new species. Aqua: 16(4), 141-170.

Tornabene, L. and F. Pezold. 2011. Phylogenetic analysis of Western Atlantic Bathygobius (Teleostei: Gobiidae). Zootaxa: 3042, 27-36.

Other Notes

Closely allied to Bathygobius soporator but dorsal fin pigmentation can separate them. The two offset rows of 6-7 pigment spots on the trunk separates B. lacertus from other species in the area.