Clownfish or anemonefish (Nemo), often found at several of the dive sites around Koh Tao living in the shelter of an anemone. They form a symbiotic mutualisms relationship with sea anemones, which means they both provide benefits to each other, the clownfish feed on small invertebrates which could harm the anemone, whilst the fecal matter from the clownfish provides nutrients to the anemone.
As they dont stray too far from the anemone mating becomes a bit more difficult, the way they solve this problem is by changing sex, all clownfish are born male, and when they are ready to mate the largest and most dominant male turns into a female. When the female dies then the largest male will become female, and continue the cycle. There are also several other fishes that go through this change aswell. Finding Nemo will never be the same again..