Zebrus zebrus ( Risso, 1827 )

Kovačić, Marcelo, Renoult, Julien P., Pillon, Roberto, Svensen, Rudolf, Bogorodsky, Sergey V., Engin, Semih & Louisy, Patrick, 2022, Identification of Mediterranean marine gobies (Actinopterygii: Gobiidae) of the continental shelf from photographs of in situ individuals, Zootaxa 5144 (1), pp. 1-103 : 89-90

Zebrus zebrus ( Risso, 1827) ( Fig. 28 )—Zebra Goby

Gobius zebrus Risso, 1827: 282 ; type locality: northwestern Mediterranean Sea , France, Gross Island, Banyuls sur Mer .

Note: This species closely resembles the recently described Z. pallaoroi , which live coloration is almost unknown, and some photographs attributed to Z. zebrus may actually depict Z. pallaoroi ; the present account is thus provisional and may not allow for a fully reliable visual differentiation of the two Zebrus species.

Size. Maximum known size about 5.5 cm total length (6.1 cm in the Atlantic, Nieto & Alberto 1992).

Morphology. D V–VI + I,11; A I,7–10; P 16–18. Small goby with a stocky body, a relatively large head and a deep caudal peduncle. Eyes quite large, snout slightly shorter than eye diameter. Head narrower than in Z. pallaoroi : head width at opercle level about 50–75 % of head length (vs. 80–90 % in Z. pallaoroi ). Anterior nostril a tube with tentacle; posterior nostril tube clearly shorter (less than 40 % of the anterior). Caudal peduncle deep, almost same depth as body. Dorsal fins of similar height, the first dorsal fin with more or less rounded margin. Uppermost pectoral-fin ray may be almost free from membrane ( Miller 1977; Louisy 2015, Kovačić et al. 2021; present work). Caudal fin rounded. Body scaled, nape and predorsal area naked. Scales more or less visible on body from reticulate pigmentation along scale edges.

Live coloration. Head and body with a beige, brownish or greenish background. Body with 6–9 pale bars along side ( Fig. 28a ), mostly visible on dorsal half ( Miller 1977, Kovačić et al. 2021) (*). In the wild, unstressed animals often display pale dorsal saddles while the rest of body is more or less uniformly colored or mottled with dark pigment ( Figs. 28b ); upper lateral dark markings reach to the base of dorsal fins. When present, the crescent band on head (broad pale transverse band across anterior nape extending on the sides until pectoral fin bases) does not extend forward to eyes ( Fig. 28b ); it is usually quite well defined in shape and contours. First dorsal fin usually with 2 dark horizontal lines (the lower one often disrupted) with a whitish band in between, outer margin of the fin often with a reddish or yellowish tint. Second dorsal fin with brownish to reddish spots that may coalesce into slightly oblique lines.

(*) The pattern of lateral bars visible on dead or stressed animals do not exactly match the number and location of lateral markings usually displayed underwater (these two pattern types may superimpose to various extents).

Similar species. Zebrus pallaoroi , Millerigobius macrocephalus , Chromogobius zebratus .

Habitat. Infralittoral species most often encountered between 0.1–3 m depth ( Miller 1977) but also recorded down to 13 m ( Engin et al. 2018a) and 36 m ( Kesici & Dalyan 2019). Occurs in a variety of inshore habitats, under stones or in rock clefts and cavities, in Cymodocea or Posidonia seagrass meadows (sheltering below shells), often in coastal lagoons ( Miller 1977, Patzner 1999a, Kovačić et al. 2012a, Trkov et al. 2019). May be found in intertidal pools ( Ahnelt 1990, Nieto & Alberto 1992, Trkov et al. 2019), and juveniles sometimes under sea urchins ( Patzner 1999b).

Geographic distribution. Recorded along the Atlantic coastline of southwest Spain and south Portugal ( Nieto & Alberto 1992; Kovačić et al. 2021) and along northern Mediterranean coasts (Miller 1986), from Alicante to the eastern Aegean Sea ( Bogorodsky et al. 2010), the Levantine Sea from Rhodes ( Miller 1977) to Syria ( Saad 2005), and from the southern Mediterranean in Tunisia and Libya ( Mejri et al. 2007). It has also been recorded from the Bosphorus Strait ( Kesici & Dalyan 2019) and the Black Sea ( Kovačić & Engin 2009; Boltachev & Karpova 2017).

Figures

FIGURE 28. Live coloration in its natural habitat of Zebrus zebrus. A) Transverse coloration pattern with pale vertical bars. B) Coloration pattern reduced to pale dorsal saddles while the rest of body lateral side is more or less uniformly colored or mottled brown; broad pale crescent-shaped band across anterior nape behind eyes, not extending onto posterior part of eyes. C) Anterior nostril with tentacle. Photos by M. Kovačić, A) Karinsko ždrilo, Novigrad Sea, B) Rava island, Zadar Arcipelago, both central Adriatic Sea.