Gobies (Gobiidae) are the family belonging to the order of Perciformes which has the largest number of marine fish among all fish families. There are species that inhabit salt, brackish and fresh waters, occurring mostly in tropical and subtropical regions, in coastal and shallow waters. Some of the species that occur in fresh water, they spawn in salt water. Gobies, along with the Combtooth Blennies, are the dominant species among small fishes on the bottoms of tropical reefs. Most species occur in the eastern Indo-Pacific region, with species occurring both north and south of the hemisphere. Numerous species live sheltered among Corals and Sponges.

One of the most distinctive features of Gobies is the presence of prominent appendages on the head. We will find in this fish family some of the smallest fishes known. For example, Trimmatom nanus is one of the smallest known Vertebrates, with adult females reaching only 8-10 mm in length. Another example is Schindleria brevipinguis, whose males reach on average 7.7 mm in length and barely 1 mg in weight. At the other extreme, the largest Gobies species reach 50 cm in length, as is the case with Glossogobius giuris.

The dorsal fin may or may not have a spiny region. In those species that have a spiny region, it is separated from the dorsal 4-10 soft radii fin region. Another characteristic feature of Gobies is their pelvic fins. These may be present or absent depending on the species, but in those species that have pelvic fins, these may be fused together to form an adhesive disc, or they may be non-fused. The adhesive disc formed by the pelvic fins is used to attach to the rocky bottom or to Algae and Corals on the seabed.

Most Gobies are solitary individuals or live in small groups. There are species of Gobies, about 120 species, which live in association with invertebrates, mainly Crustaceans. These associations occur mainly on reefs, and by which the Goby defends the invertebrate, while the Crustacean provides them with shelter and food. There are also other species of Gobies (mainly Elacatinus genus) very sought after by many reef fishes, as they specialize in feeding on ectoparasites and therefore deworming other fishes. Gobies feed mainly on small marine invertebrates, although there are also species that are herbivores. Another curious fact is that certain species of Gobies present sequential hermaphroditism, that is, part of the life of an individual has one sex, and later they change to the opposite sex in a second stage of their lives. Likewise, many of the species actively care for their clutches by aerating and protecting them until the time of hatching. As we mentioned at the beginning, Gobies are the family of fish that contains the largest number of species among the fish. There are described 1,359 species classified within the 189 existing genera. On coral reefs, Gobies can make up 35% of the total fish population and up to 20% of the species diversity.