Gobius paganellus Linnaeus, 1758 (Fig. 57)—Rock Goby

Gobius paganellus Linnaeus, 1758: 263, type locality: Mediterranean Sea.

Size. Known adult size about 12 cm total length.

Morphology. D VI + I,12–15; A I,10–13; P 15–20. Medium-sized goby with a proportionally short and stocky body. Head wide and moderately depressed. Caudal peduncle deep, but lower than body. Dorsal fins of similar height, the first dorsal fin may be slightly higher, with a more or less rounded distal edge and no elongate spines. Pectoral-fin free rays very well developed. Caudal fin rounded. Predorsal area and nape entirely covered with large scales. Scales visible on body and usually also on predorsal area (Miller 1986; Louisy 2015).

Live coloration. Background coloration highly variable, ranging from light beige to dark brown (Fig. 57a). Nesting males occasionally entirely black, with just the first dorsal fin margin colored (Fig. 57b). Most frequent pattern: broad dark bars and thin alternate white saddles on the back, medium-sized dark blotches along lateral midline, and small dark markings on a light background below. Usually a pale to white bar between eye and corner of mouth; it is often preceded by a dark preorbital bar. First dorsal fin usually dark with an orange to yellow marginal band (Renoult et al. 2022).

Similar species. Gobius ater, G. cobitis, Millerigobius macrocephalus, Zebrus zebrus, Z. pallaoroi .

Habitat. Infralittoral species known from 0.5–20 m depth on very diverse hard or mixed bottoms (Patzner 2021; P. Louisy unpublished observation).

Geographic distribution. The whole of the Mediterranean (Miller 1986), Black Sea (Engin & Seyhan 2009) and Eastern Atlantic from Great Britain to Senegal (Miller 1986), including the Azores (Santos et al. 1997), the Canary Islands (Wirtz 1994) and Madeira (Wirtz et al. 2008).