Common Name
Frillfin Goby
Year Described
Valenciennes, 1837
Identification
Dorsal Fin: VI, I-9
Anal Fin: I, 8
Pectoral Fin: 18-21 (mode of 20)
Caudal Rays: 17 upper, 16 lower lobe (all types)
Scale Rows: 38-42
Pre-dorsal Scales: 19-22
Body of typical shape for the gobies but robust. Eye medium sized; about equal to snout length. Upper jaw more than 11% of SL. Pectoral fin extends to rear margin of first dorsal. Upper 4 pectoral rays (rarely 3 or 5) separate from membrane; bifurcated. Pelvic fins fully fused into disk. Pelvic fins reach or fall just short of anus. Caudal fin rounded. Body fully scaled with scales extending forward of level of pre-opercular margin.
Color
Body pale brown with longitudinal medium brown stripes following scale rows. There are usually 6-7 large dark brown blotches on the mid-side and other blotches both above and below this row. Bands formed by blotches are irregular to oblique but not checkerboarded. Dorsum and head with irregular dark blotches. First dorsal fin with a single thick oblique stripe (not double or horizontal). Second dorsal fin and caudal fin with rows of dark spots and a yellowish stripe. Tail with a basal black rectangular blotch. Anal fin dusky. Pelvic fin pale. Pectoral fin yellowish.
Size
Maximum size to over 100mm SL.
Habitat
Found in shallow coastal waters on both rocky and sandy bottoms, in mangrove lagoons, tidepools, on jetties and human-built structures, or in rubble and pebble strewn areas. Mostly restricted to sheltered habitats.
Range
Widespread from South Carolina to Brazil, including the Gulf of Mexico and the Caribbean Sea (mostly continental).
References
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
The limits of the range and taxonomic identity of lineages (species complex?) assigned to Bathygobius soporator are unclear. Whether this species occurs in Brazil or the eastern Atlantic, or if these are undescribed, remains to be seen. All Bathygobius with the single oblique dorsal fin band are placed in this species for the time being. Sister to B. andrei from the eastern Pacific.