Sea Stars

The sea stars or also commonly known as starfish. However, it is not a fish despite of being called starfish. They belong to the phylum Echinodermata under the subclass Asteroidea. Sea stars could have more or lesser that five arms, have a symmetrical with five axes, a spiny skin and tube feet. Some sea stars tends to have a long narrow arms and a small central disk. Some tends to have short arms that makes them look like a pentagon such as the cushion sea star. The sea star use their tube feet to move around. The mouth of sea star is located under their body facing the ground, thus they often graze on other organisms for feeding.

Most sea stars are scavengers or carnivores, they preys on coral polyps and other small sessile invertebrates. In Pulau Kapas, some of the sea star that can be found here is the crown-of-thorn sea star (COTs) and cushion sea star. The COTs feeds on the polyps of hard corals and leaves a spotted dead white skeleton corals. If there are overpopulation of COTs in the reef ecosystem, they are only bring danger and destruction to the reef.

Amazing fact about cushion sea star, if they are overturned, they can turn themselves back up by inflating the body so the upper side is very round. The action of waves then turns the sea star the right side up.