Monkey goby Estuary. It plays an important role in the food chain by serving as prey for other predatory fish living in these areas. Monkey goby The monkey goby ("Neogobius fluviatilis") is a species of goby native to the basins of the Black Sea and the Sea of Azov. The monkey goby is covered with cycloid scales on the head crown, nape, back, one third of the gill covers, bases of the pectoral fins, and the posterior half of the throat and belly. Its second dorsal fin is small in size compared to the posterior end of the body. The width of
Sand goby rounded. In males, there is a conspicuous dark spot on the anterior dorsal fin and in both sexes there is a black patch on the caudal peduncle. The general colour is sandy brown with indistinct dark blotches and reticulations on the dorsal surface and dark striations on the pale fins. The colour of the male darkens during the breeding season and his fins become more coloured. The average size is about . The sand goby normally lives at greater depths than the common goby. It feeds on small invertebrates living on the seabed especially amphipods. It is well camouflaged and