Wednesday, June 04, 2008

Intertidal Life of Pulau Tioman

It was certainly great to be back at Pulau Tioman, this time round, with Hwa Chong Institution. I certainly missed the interesting intertidal organisms I saw last year, and it's just wonderful to be back here to see the familiar organisms as well as new ones. We had our intertidal walk in the morning after breakfast, as the tide was the lowest around 8am when it was already very bright.

Interestingly, last year when I was here with Pioneer Junior College, we had the intertidal walk at night, and the students asked me why we couldn't have the walk in the day when it was brighter and easier to see things. This time round, however, the Hwa Chong students asked me why we couldn't have the intertidal walk at night when more animals will come out. Well, what to do? We have to follow the tide!

Anyway, back to the organisms I saw...

The cryptic rock stars (Cryptasterina sp.) were still every where on the rocky shore.

Have no idea what sea star this is, but we saw a similar looking one last year. (Update: Received an email recently from a scientist, Chris Mah, who works on the systematics of starfish. He informed me that this is a juvenile cushion star (Culcita novaeguineae). Thanks Chris!)

Our hunter-seekers during the intertidal walk found us several brittle stars too.

Lollyfish sea cucumbers [Holothuria (Halodeima) atra] were every where...

There were lots of tiger tail sea cucumbers (Holothuria hilla) too.

It took both ST and I quite a while of searching to eventually find this pinkfish sea cucumber (Holothuria edulis). I saw many of them last year. Not sure why there were so few of them this time round. Could they be seasonal?

Not exactly sure of the ID, though I think this could be a greenfish sea cucumber (Stichopus chloronotus).

So far, I've seen two types of sea urchins on Tioman. The one above is an long spined sea urchin (Diadema setosum).

This one is probably an Echinothrix calamaris.

I was rather delighted to find several Christmas tree worms (Spirobranchus giganteus). Since I haven't pick up diving yet, I hardly get the opportunity to see them, since they are usually found in deeper waters. In fact, I've only seen it once in the intertidal zone in Singapore, and that was at Kusu Island.

Probably due to the clear water, there were lots of burrowing giant clam (Tridacna crocea) on the rocky shore.

Nearer to the high water mark, clusters of oysters were every where! Many of them even have barnacles and limpets on them.

We saw this same type of sea hare (Dolabella auricularia) last year too!

This is probably a blue dragon nudibranch (Pteraeolidia ianthina).

Think this is an olive snail, but not sure of the exact ID though.

I found lots of cone shells last year, but this year, surprisingly, we only found a few. This snail is venomous though, so if you happen to see it next, please don't touch it.

We also found a pretty Arabian cowrie (Cypraea arabica). Regularly saw it on some of our shores too.

Another new sighting this year was this pretty white-spotted hermit crab (Dardanus megistos).

Some how, we also found lots of smasher mantis shrimps this year.

Last but not least, the corals. Tioman certainly has lots of corals, but diversity wise, I think our local intertidal zones are still much richer. Tioman shore was very densely covered with corals though, unlike what we have in Singapore, where our intertidal zones are usually sparsely covered.

Still, I think I still like our shores better :P

But it sure was nice to look at something different once in a while :)

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