The Common Starfish or Common Sea Star (Asterias rubens) is the most common and familiar starfish in the north-east Atlantic and Indian Ocean.Star fish are not fish. And they are not shells. They are echinoderms and are closely related to the Sea Urchin and Sand Dollar. They don't all have 5 arms. The starfish, or sea star, called the "Sun Star" can have up to 40 arms! They can be found in all the oceans of the world but you will most likely come across one in a tide pool. Like certain types of lizards, star fish can drop an arm to escape a predator. The arm will grow back but takes about a year to do so. Birds, fish and sea otters are it's predators. Star fish have an eye spot at the end of each arm. They can weigh 11 pounds and live up to 35 years. The Common Starfish is usually orange or brown, and sometimes violet; deep-water specimens are pale. The Common Starfish is to be found on rocky and gravelly substrates.It reproduces asexually.