The Goby is not a single species but a massive family of small, bottom-dwelling fish known as Gobiidae. Although there are hundreds of species, they all share a unique, defining characteristic: their two pelvic fins are joined to form a suction cup. This adaptation allows them to attach firmly to rocks and stones, resisting marine currents. The body is usually small and cylindrical, with a large head, puffy cheeks, and eyes positioned high to monitor the surrounding area.

In the Mediterranean, several species are distinguished. The Black Goby is the largest species, reaching 15 centimetres, and is dark in colour; it lives in mud or sand. The Rock Goby lives among shallow rocks and the tide pools of the coastline. Sand Gobies are tiny and transparent species that live exclusively on sandy substrates.

These are fish that dominate every type of seabed in the coastal zone. They are found everywhere, including rocky shores and sandy beaches, Posidonia seagrass meadows, and brackish waters such as lagoons and river estuaries. They usually live in very shallow waters from a few centimetres down to depths of 70 or 100 metres.

The majority of species are small, with a length rarely exceeding 10 or 12 centimetres. Only certain species, such as the Black Goby and the Giant Goby, can reach lengths between 15 and 25 centimetres.

They have very low commercial value and are rarely sold in markets except for some areas where they are fried. They are easily caught from the shore with a rod, a handline, or a landing net. However, they are valuable to recreational anglers as they are among the best and most resilient live baits for catching large predators such as sea bass.

The International Union for Conservation of Nature classifies most species of this family as Least Concern because their populations are large and stable. Scientific studies have shown that they play a critical role in coastal ecosystems by transferring energy from small bottom organisms to larger fish. Furthermore, research in lagoons has shown that they have a short life cycle of 1 to 3 years and reproduce quickly, allowing them to replenish their populations immediately.