Image source: IHUNTA | inaturalist.org
The grass goby (Zosterisessor ophiocephalus) is a species of goby native to the Mediterranean Sea, the Sea of Azov, and the Black Sea. Grass gobies can grow up to 25 cm (9.8 in) long. The head crown, nape, throat, belly, and bases of the pectoral fins are covered by cycloid scales, and the gill covers are naked. The abdominal sucker has no blades and does not reach the anus. The mandibulae are protrusive, and the skin soft, with mucus. Their coloration is green-brown, patterned with merging brown spots. The cheeks have round light spots. The dorsal, caudal, and pectoral fins have longitudinal brown stripes on a light background; the anal and abdominal suckers are dark. Widespread in coastal waters of all seas of the Mediterranean basin, they are especially numerous in the northern Adriatic Sea, Venetian Lagoon, and Sète Lagoon (France) and in the Black Sea near all coasts, especially in lagoons and estuaries of the north-west, Varna and Burgas Bays, Sea of Azov, and Sivash.
