Ctenogobius Gill, 1858

Ctenogobius Gill, 1858 View in CoL

Te genus Ctenogobius was redefined by Pezold (2004) and reviewed by Pezold (2022), where 15 species were recognized, two of which in the East Pacific, 12 in the West Atlantic, and one in the East Atlantic. We figure otoliths of the following extant species: Ctenogobius boleosma ( Jordan & Gilbert, 1882) ( Fig. 42a–c View Fig ), C. fasciatus Gill, 1858 (Fig, 42f–g), C. shufeldti ( Jordan & Eigenmann, 1887) ( Fig. 42i–j View Fig ), C. smaragdus (Valenciennes, 1837)

( Fig. 42k–m View Fig ), and C. stigmaticus (Poey, 1860) ( Fig. 42p View Fig ) from the West Atlantic; and C. manglicola ( Jordan & Starks, 1895) ( Fig. 42h View Fig ) and C. sagittula (Günther, 1862)

( Fig. 43a–c View Fig ) from the East Pacific. For further comparison, otoliths are figured from the extant Evorthodus lyricus (Girard, 1858) ( Fig. 42v–x View Fig ), E. minutus Meek & Hildebrand, 1928 ( Fig. 42y View Fig ), Gobioides peruanus (Steindachner, 1880) ( Fig. 43f View Fig ), and G. broussonnetii Lacepède, 1800 ( Fig. 43g View Fig ). For the genera Gobionellus and Gnatholepis , see below.

Otoliths of the genus Ctenogobius show considerable variation, but are mostly compressed, usually higher than long (OL:OH ≤ 1.0), with a sole-shaped sulcus. Te details of the otolith outline, particularly the dorsal rim, vary from one species to another, but the otoliths usually show a moderate or regressed postdorsal projection. Te otoliths of one species, however, differ considerably from those known of other species. Ctenogobius sagittula has more elongate otoliths (OL:OH = 1.05–1.15), a massively developed postdorsal projection that expands toward dorsally and posteriorly with a flat to slightly concave middorsal section and the presence of a distinct subcaudal iugum. Te species also keys out first in the identification key published by Pezold (2022), who confirmed in a personal message (2023) that C. sagittula is the most divergent species in the genus. Otoliths of Evorthodus have a reduced sulcus morphology. Tose of Gobioides also show a somewhat simplified sulcus morphology, a nearly horizontal sulcus, and a distinct circumsulcal furrow composed of the ventral furrow and the furrow-like dorsal depression.

Species of Ctenogobius inhabit shallow sand and mud bottoms in bays and estuaries, often in tidal or mangrove environments. Many species are euryhaline and enter brackish water; some inhabit fresh and brackish water ( Pezold, 2004, 2022). Most species of Ctenogobius are facultative air-breathing ( Froese & Pauly, 2023).