What Divers Should Know About Starfish

Gliding over a vibrant coral reef or investigating a rocky outcrop, you’re almost guaranteed to spot a starfish. These captivating marine invertebrates are benthic animals, meaning they live on the seabed, inhabiting sandy, muddy, and rocky substrates across all the world's oceans, from warm tropical zones to frigid polar regions. You can find them anywhere from shallow coastal areas to incredible abyssal depths, reaching at least 6,000 meters below the surface. Many species showcase a dazzling array of colors, often in shades of red or orange, but also blue, grey, or brown, making them a stunning subject for underwater photographers.

Typically identified by their central disc and five radiating arms, some species boast an even greater number—up to 10-15 arms, or even over fifty in certain Antarctic varieties. Observing their unique movement, propelled by a hydraulic system controlling their tube feet, reveals their role as opportunistic predators, primarily feeding on other benthic invertebrates. A fascinating trait is their ability to regenerate lost or damaged arms, even shedding an arm as a defense mechanism if threatened. While largely sedentary, their vibrant presence and intriguing biology make them a delightful and common sight on any dive.