I am not a real knowledgable fellow regarding seastars, all I could comment is that your one (Pentagonaster duebeni) was/is probably feeding on the coral polyps. Most seastars are predators or scavengers, so I think it is quite possible that this little red beast got the better of the coral.
Solitude Liveaboards Solitude Liveaboards was created with their clients in mind. Redefining luxury with its design, creating purposeful and functional spaces for rest and play. Based in Palau, the fleet will extend to Indonesia by 2016.
20th July 2003 .... that is the first time I drove down from the Gold Coast to Byron Bay and arrived at Sundive, jumped on one of their boats and set out to dive Julian Rocks - and I have been addicted ever since