Accidentally Hantu

6am and we're off. We were originally planning to go to Cyrene but alas, there were boat problems so to Hantu we went instead. No it's not lightning striking the petrochemical plants. It's daybreak over Pulau Bukom which lies just opposite Pulau Hantu.Despite the proximity of major industrial installations, the shores of Hantu are very much alive. With these humungous soft corals which seem to keep multiplying!Each large soft coral, that remind me of fried eggs, is actually a colony of tiny polyps that look like miniature sea anemones with a body column topped by branching tentacles. The polyps live in a shared leathery tissue.

Pulau Hantu is also full of hard corals. They come in a variety of colours and shapes. Hard corals are also a colony of tiny polyps, but each polyp creates a tiny hard skeleton called a corallite. Each colony is made up of the joined up corallites of countless polyps.This is a pink plate-like Turbinaria sp. coral.A pretty green boulder-shaped coral with ring-shaped corallites. I don't know what kind of hard coral this is.A beautiful branching Acropora sp. coral. This kind of coral is rather rarely seen on our intertidal.
And a blue mushroom hard coral (Family Fungiidae). Unlike most other hard corals, most mushroom hard corals are a single polyp!Another mushroom hard coral, Heliofungia actiniformis. It is also a single large polyp with long tentacles ending in white rounded tips.

Just to make things confusing, there's the Blue coral (Heliopora coerulea). The coral isn't blue and it isn't a hard coral even though it has a hard skeleton. Their internal skeletons are blue, hence their common name. The blue colour is due to the iron salts that are incorporated into their skeletons. On the outside, they are usually brown because the thin layer of living tissue that covers the outer surface of the skeleton is brownish.The tiny polyps have eight tentacles with fine branches like other soft corals. Thus they are grouped with other soft corals. True hard coral polyps have smooth tentacles in multiples of six.

Blue corals are considered living relicts of fossil species known from more than 100 million years ago. Most other corals have an evolutionary age of only several hundred thousand years. Blue corals used to be dominant before the last Ice Age when the seas were warmer.

There are indeed a bewildering variety of hard and soft corals on our shores!And all kinds of other marine life crowd the shores of Pulau Hantu.
Pulau Hantu is a great place to see large sea anemones still common on our reefs. The Magnificent anemone (Heteractis magnifica) is in the photo on the right, and the Giant carpet anemone (Stichodactyla gigantea) is on the left. Both these anemones usually host clown anemonefishes and anemone shrimps. Unfortunately today, I didn't see any. Although Annabelle saw one anemonefish. I do hope this doesn't mean something negative is happening to the shores.

There were also lots of Phymanthus sea anemones with branching tentacles, and the odd star-shaped sea anemone that is NOT Condylactis.

But here's one sea anemone that I've not seen before.Could it be a Bulb-tipped sea anemone (Entacmea quadricolor) with 'deflated' tentacle tips?I don't really know.

A good reef is also a great place to find nudibranchs. And today, all the usual suspects were present.The phyllids are lumpy little nudibranchs without an external gill. The one in the left photo is Phyllidiella pustulosa and the one on the right is Phyllidiella nigra. These two nudibranchs are quite commonly encountered on our reefs. Nudibranchs are generally unpleasant or toxic to eat and advertise this with bright patterns or colours.Also commonly encountered is the frilly lemon yellow Glossodoris atromarginata, and the nudi-in-pajamas Chromodoris lineolata.

In fact, Glossodoris atromarginata was so abundant they were seen in groups, appearing rather sad and blob-like out of water during the low tide.I almost missed the Hairy crab (Family Pilumnidae) that was right on top of this Glossodoris atromarginata. Was it about to eat the nudi? The Hairy crab is known to eat toxic animals such as zoanthids. I didn't find out as the crab quickly scuttled away.

Here's a strange sign on the sea wall of Pulau Hantu.This is rather odd as Pulau Hantu is one of the favourite dive spots in Singapore with many exciting dives conducted by the Hantu Bloggers. And Pulau Hantu is the only site designated as a dive spot in the URA Draft Master Plan's Leisure Plan.

And just off Pulau Hantu, the humungous oil rig located off Pulau Semakau can be seen. Here's the MPA notice about the oil rig. Here it is in the distance with the seawall and reefs of Pulau Hantu in the foreground.On the way home, we take more photos of it. Here's indications of the locations of Pulau Semakau, Raffles Lighthouse (RLH) and Pulau Senang. Raffles Lighthouse and the Live Firing Islands of Sudong, Pawai and Senang have some of the last untouched reefs in Singapore. While Pulau Semakau has good natural shores. Let's hope this massive activity does not impact these nearby reefs. Here's a closer look at the oil rig.

On the way home, we have a faraway look at Cyrene Reef.It's a submerged reef so hardly anything sticks out.
Except the beacons to mark its location so ships can avoid it.

Let's hope we can go ahead with our plans to go to Cyrene tomorrow!

Andy shares a wonderful clip of an octopus he saw changing colours on the sgbeachbum blog