Goby (Gobius), a genus of carnivorous shore fishes, abundant on all temperate, and yet more on tropical coasts. The genus is type of a family, Gobiidae, included among the acanthopterous bony fishes. The gobies are generally small; the bodies are scaly; of the two dorsal fins, the anterior has usually six flexible spinous rays; the ventrals are united to form an adhesive disc, by means of which the fishes cling to the rocks, withstanding the rush of the waves; there is no swim-bladder. Their favourite habitat is on rocky coasts; 'many,' Günther says, 'seem to delight in darting from place to place in the rush of the water which breaks upon the shore; others live in brackish water, and not a few have become acclimatised in lakes. In various degrees the gobies change their colour to suit the ground on which they rest. The males of some species build nests of seaweeds and sea-wrack, and watch these jealously till, and even after, the hatching of the eggs which their mates have laid.
The genus includes about 300 species, of which several are common on British coasts. Of the latter the Black Goby (G. niger) is the largest, but only measures 5 or 6 inches; G. ruthensparri, G. minutus, G. paganelius, are other well-known species. They make interesting inmates of aquaria. The White Goby (Latrunculus albus) is a very small transparent fish, found on some British and European coasts, remarkable as 'the first instance of an annual vertebrate,' for it seems only to live one year. There are numerous genera very nearly related to Gobius, while not far off is the genus Periophthalmus, the members of which have greatly protruded eyes and are accustomed to hunt along the ebb-tide shore, hopping and leaping with some agility. The Dragonets (q.v.) are also allied. See Günther's Study of Fishes (Edin. 1880).