Gobius cruentatus Gmelin, 1789 (Fig. 15)—Red-mouthed Goby

Gobius cruentatus Gmelin, 1789: 30, type locality: western Mediterranean Sea, France, Marseilles.

Size. Known adult size about 13–15 cm total length.

Morphology. D VI + I,14; A I,12–13; P 20–21. Large goby with stout body, moderately long snout with moderately steep profile, thick lips. Caudal peduncle deep, but lower than body depth. First dorsal fin higher than the second dorsal fin; first dorsal fin spines decreasing posteriorly, shaping a curved margin. Caudal fin rounded. Predorsal area and nape scaled. Scales small, visible on body and predorsal area as dense pattern.

Live coloration. Body mostly mottled brown, with large darker, squarish midlateral blotches, each one preceded and followed by a white patch (Fig. 15). Back with 4 broad dark transverse bands, the second and fourth the darkest, separated by thin white saddles (Fig. 15). Lips mostly vermilion, with a white bar below eye, at angle of mouth (Fig. 15) (red color usually not detectable under natural light only). Membranes of both dorsal fins are highly variegated, mixing irregular patches of red, dark brown and white coloration. Rows of head sensory papillae well-visible and bicolored black and white.

Similar species. No similar species in the Mediterranean. However, with no artificial light, may be confused with Gobius paganellus or G. niger.

Habitat. Infralittoral species, known from 1–40 m depth on inshore rocky habitats, sand with stones and boulders, and in seagrass meadows (Miller 1986; Louisy 2015; Patzner 2021).

Geographic distribution. Northeastern Atlantic, Mediterranean and Black Sea (Engin et al. 2007; Vasil’eva 2007). In the Atlantic, occurs from the counties of Cork and Kerry in Ireland to Western Sahara (Miller 1986). In the Mediterranean, all along the northern coast, and along the southern coast in Morocco, Algeria and Tunisia (Miller 1986), as well as in Benghazi in Libya (Al-Hassan & El-Silini 1999).