Rock Goby

The Rock Goby (Gobius paganellus) is a small coastal fish native to the eastern Atlantic Ocean, ranging from western Scotland to 🇸🇳 Senegal, and is also present in the Mediterranean and Black Seas. Its adaptability allows it to migrate to the 🌊 Red Sea via the Suez Canal (🇪🇬 Egypt). This fish prefers subtropical environments and is typically found in shallow waters at depths between 1 and 15 meters (3 to 49 feet). It can thrive in marine, brackish, and freshwater environments, commonly inhabiting sheltered rocky shores with abundant algae, where it can hide in intertidal pools or beneath stones.

The rock goby grows up to 12 centimeters (4.7 inches) in length and can live for as long as ten years. Its appearance is notable for being usually black with white blotches, although the color can change; males are particularly darker during egg-guarding. Its distinctive features include a scaleless neck and a pale band atop the first dorsal fin, with no black spots on the leading edges of both dorsal fins.

As an amphidromous species, the rock goby feeds on various marine organisms. Adult gobies mainly eat crustaceans such as amphipods, isopods, and small crabs, as well as polychaete worms. Juvenile rock gobies have a diet consisting of harpacticoid copepods, amphipods, polychaetes, and mites.

Reproduction occurs in spring, when the rock goby lays up to 7,000 fusiform-shaped eggs, each about 2.5 millimeters (0.1 inches) in height. These eggs are deposited in a single layer under rocks, shells, or other substrates like polychaete tubes, and are vigilantly guarded by the male for approximately 19 days until they hatch. After hatching, larvae remain near the ocean floor and begin to exhibit the adult cryptobenthic behavior. The rock goby is a repeat spawner, meaning it can reproduce multiple times throughout its life.

Overall, the rock goby is a fascinating species well-adapted to its diverse habitats, and plays a vital role in its ecosystem as both predator and prey.