Pulau Hantu has always been a great home for a wide variety of mushroom corals.It was fabulous to see so many large specimens of these amazing animals on the reefs of Hantu today.
Unlike most other hard corals which are colonies of tiny polyps, some of the mushroom corals of the Family Fungidae are humungous solitary polyps!
This circular mushroom coral, for example, is a solitary polyp with one mouth in the centre, and lots of little tentacles sticking out of its hard skeleton.I'm not sure if this mushroom coral has shorter tentacles, or just hasn't expanded them.
The other amazing thing about mushroom corals is that they are not attached to the surface as adults. In the photo above, the hard coral on the left is stuck to the ground and made up of tiny little polyps. While the circular mushroom coral on the right is a solitary polyp which can move! But they do this very VERY slowly.
However, a mushroom coral starts life stuck to a hard surface and in fact looks like a tiny stalked mushroom. In many species, as the coral matures eventually breaks away from the stalk.
There were many mushroom corals on the sandy patches among the hard corals at Pulau Hantu. There were big ones and little ones. And in many splendid colours.These are probably Herpolitha sp. which I call Tongue mushroom corals because of their shape. Some consider these to be colonial animal with many mouths. Numerous mouths are found in the central groove and mouths may also be found elsewhere on the upper surface.
Here's another Herpolitha which was quite large.
There are other long-shaped mushroom corals which are different, like the huge one above. I don't really know what they are.There are mushroom corals with smoother walls, which come in circular and long shapes. I also don't really know exactly what they are.Here's another one with smooth walls.Another kind of mushroom coral that is more often found in silty areas near seagrasses is the Sunflower mushroom coral (Heliofungia actiniformis). It has cylindrical white-tipped tentacles that look like udon noodles.
The only mushroom coral I didn't see today at Pulau Hantu were the Mole mushroom coral (Polyphyllia talpina). But perhaps I just missed them in the excitement of exploring the reef.