Tuesday, April 27, 2010

Pulau Tioman with Canadian International School Singapore

When I told my brother that I was going to Pulau Tioman for 8 days, his response was, "Are there that many things to see on the island?"

But of course, I was not there for a sight-seeing or leisure trip. We were conducting a field study camp for Canadian International School Singapore!

While we will be staying on the island for 8 days (17-24 April 2010), the students would only spend 4 days on the island. That's because we were running 2 camps consecutively for 2 different batches of students. There were about 40 students per batch.

We met around 5 plus in the morning at the school, and took a chartered bus to Tanjung Gemok to be transferred to a ferry to Pulau Tioman.

We were rather lucky that the ferry left on time, and we reached the island around 1 plus in the afternoon. After lunch, we had our first activity - an orientation walk around Paya Beach Resort. This walk also introduced some of the coastal and mangrove vegetation to the students.

Many coastal plants have thick leaves to retain water, since the coastal environment is very dry due to the sea and land breeze which increase the rate of evaporation. This is a hoya plant (Hoya sp.), and even its flowers have thick petals! The leaves often have very smooth surfaces to ensure that any salt from salt sprays will be easily swept away by the wind.

Near the hoya was a stingless bee (Tribe Meliponini) hive. These bees have highly reduced stings that cannot be used for defense.

We spotted this centipede (Class Chilopoda) on a sea apple tree (Syzygium grandis) for the first batch of students. It was feeding on a caterpillar!

There was also this poor bee that was attacked by red weaver ants (Oecophylla smaragdina). These ants are very aggressive and give painful bites.

Apart from the organisms above, the students also saw other plants like the casuarina, cashew, lemon grass, mistletoe, nipah palm, sea lettuce, sea morning glory, bakau, etc. Other animals we saw include many different types of butterflies, grasshoppers, fiddler crabs, mudskippers, spiders, etc.

On the second day, the students started off with an intertidal walk in the morning. Paya Beach Resort has a very nice intertidal area with huge colonies of corals.

While we did not see the cryptic rock stars (Cryptasterina sp.) for the first batch of students, we saw quite a few of them for the second batch! These sea stars were quite small, and camouflaged very well with the surrounding rocks.

We also found a few juvenile cushion stars (Culcita novaeguineae). This was a rather special one with 6 arms!

We also found a mature cushion star, and it certainly looked quite different from the juveniles, appearing more like a huge cushion. These sea stars feed on corals.

There were lots of sea cucumbers here, and this was just one of them - a lollyfish [Holothuria (Halodeima) atra]. They feed on tiny organic matter on the sand, picking them up with oral tentacles.

One of the groups found this cluster of eggs under a rock! They looked like octopus eggs to me. For the first batch of students, we saw a few octopuses too, but unfortunately I forgot to take photos.

One of the groups found this pretty file clam (Limaria sp.) under a rock. It had lots of tentacles, which could break upon contact with predators to distract the latter. It could swim by flapping its two halves of its shell too.

There were a few cone snails (Family Conidae) too. These snails are venomous, and one should never handle them with bare hands. Some cone snails stings can even be fatal!

There was also a spider conch (Lambis lambis), which got its name from the many spines extending from its shell.

Other organisms we saw include lots of seaweeds, a few seagrasses, brittle stars, nudibranchs, sap-sucking slugs, various types of crabs, shrimps, cowries, giant clams, oysters, etc.

In the afternoon, we did a stream study to check out the organisms living inside. We saw many freshwater crabs, shrimps, snails and insect larvae. Did not take many photos except the two below though.

This is probably a dragonfly larva. They feed on other small animals in the stream.

This should be a Bucccinid snail (Family Buccinidae). It had a long proboscis for sniffing out its food. Not sure what it feeds on though.

Interestingly, we found a dog-faced water snake (Cerberus rynchops) here! This snake can be commonly found in the mangrove, but this was the first time I saw it in a freshwater stream, quite a distance from the mangrove! Could it have swam upstream from the river mouth?

We saw more of these snakes during our night walk on the same evening, when we walk into the mangroves.

But the main attraction of the mangrove, at least for me, was this mud lobster (Thalassina anomala). This animals is hardly seen above ground, as it spends most of its time in its burrow. Mud lobsters are very important in the mangrove ecosystem, as they feed on organic matter in the mud, and as they feed and dig, they bring fresh mud nutrients to the surface, forming huge mounds. Many plants (ferns, coastal plants etc) and animals (crabs, insects, snakes etc) grow/live on mud lobster mounds, due to the availability of nutrients, and the tall mounds allow these organisms to stay out of the reach of sea water.

During the night walk, we also ventured into the secondary forest, and saw a few night animals like this terrestrial flatworm.

The highlight of the walk in the forest would be the numerous Horsfield's flying squirrels (Iomys horsfieldi) we saw high up on the sea apple trees. And they were feeding on the sea apples! These small mammals have a flap of skin on each side of its body, between the front and back legs. They can glide from tree to tree by spreading their limbs as they jump, hence extending the flap like a kite.

We also saw many bats, a few fireflies and several huge spiders.

On the third day of the camp, we went snorkeling!

The first snorkelling site we went was Renggis Island. It's a natural reef with lots and lots of hard corals!

There were lots of fishes too! The above were mostly sergeant damselfishes (Abudefduf spp.)

There were many black long-spined sea urchins (Diadema setosum). These animals have venomous spines which give painful stings.

Another animal with venomous spines was this crown-of-thorns sea star (Acanthaster planci). This sea star feeds on corals.

There were many huge sea anemones here too. The above are magnificent sea anemones (Heteractis magnifica). Can you find the clownfish among the tentacles?

Here's a closer look at the clownfish - an ocellaris clownfish (Amphiprion ocellaris). The clownfish has a layer of mucus on its body, preventing it from being stung by the sea anemone. It is protected from predators among the stinging tentacles, and in return, it chases away fishes that feed on the tentacles of the anemone.

We spotted a few stinging hydroids, but fortunately, not one was stung by them. They appeared like little, feathery trees, but could give painful stings when contact.

There were lots of giant clams (Tridacna spp.) too. The above should be a fluted giant clam (Tridacna squamosa).

The next stop was an artificial reef.

There were lots of man-made concrete structures on the seabed, but very few corals were growing on them.

There were lots of fishes though, and the students thoroughly enjoyed snorkeling among them.

We saw many silver moonies (Monodactylus argenteus).

These are orange-spotted rabbitfish (Siganus guttatus). They have venomous spines that can give painful stings.

Closely related are these double-barred rabbitfish (Siganus virgatus).

The trevallies (Family Carangidae) were a common sight here, and we saw huge schools of them.

So were the scissortail sergeanst (Abudefduf sexfasciatus).

The most colourful fish we saw must be the parrotfish (Family Scaridae). They possess parrot-like beaks which allow them to rasp algae from corals and rocks.

Interestingly, I found this anemonefish, which I thought looked like a black variety of Clark's clownfish (Amphiprion clarkii), swimming up and down the water column. A closer look revealed that it was picking up crumbs of bread thrown down by tourists, and bringing them back to its host sea anemone! Studies have shown that anemonefish feeds its host anemone with food that they found, but never did I expect to see it happening with my own eyes in the wild!

Soon, it was time to go. I was rather happy that I managed to get a photo which captured both the above and under water scene! :P

In the afternoon, the students were given a group project, and finally we instructors got to rest for a while. It drizzled a little during the project discussion for the first batch, and we were greeted by a beautiful rainbow when we went to the restaurant for dinner!

On the whole, it was a great trip, with 2 batches of very lively students! Hope the students enjoyed the field study camp as much as we do! :)

More photos of the trip at:

Thursday, April 08, 2010

A Rainy Semakau Walk on 4 April 2010

The sky was overcast when I left home around 5.20am on 4 April 2010. When I reached Marina South Pier, it started raining. To think that it had been bright, sunny and very hot for the past few days, we were indeed a rather unlucky that we should get bad weather when we were going to conduct a Semakau walk!

I was guiding a group of students from Raffles Institution, and my group name was "Seahorse". The students soon arrived, but the rain still had not stopped! We boarded the boat and after about an hour, we reached Semakau.

The rain had stopped then, but only to start again when we reached the entrance to the secondary forest. As a result, we had to wait for about an hour under a shelter until the rain was less heavy and eventually become a little drizzle, and I decided to bring the group to the intertidal area.

Despite the rain, I have to say we were still lucky enough to see many interesting organisms, even though most of them were hiding from the rain!

Here's my group crossing the seagrass meadow. The rain had almost stopped then.

Heart Cockle (Corculum cardissa)
This is a Heart Cockle (Corculum cardissa), and this is definitely one of my favourite clams on Semakau! It got its name from its heart-shaped shell. This cockle can burrow into the sand, and thus it can be rather hard to find them sometimes.

Cushion Star (Culcita novaeguineae)
We have been regularly spotting juvenile Cushion Stars (Culcita novaeguineae) for past one year. They appeared to be moving towards the reef edge though. This sea star feeds on corals, and as it grows bigger, the arms will be less obvious and it will look more like a pentagon-shaped cushion instead, hence the common name.

Green Ceratosoma Nudibranch (Ceratosoma sinuatum)
The Green Ceratosoma Nudibranch (Ceratosoma sinuatum) appear to be in season, and we have been seeing them for the past few trips.

Black Long-spined Sea Urchin (Diadema setosum)
This small Black Long-spined Sea Urchin (Diadema setosum) appeared to have been trapped in a tidal pool by the receding tide. They have venomous spines, and thus should not be handled with bare hands.

Knobbly Sea Star (Protoreaster nodosus)
As usual, the star of the trip is the Knobbly Sea Star (Protoreaster nodosus)! This huge sea star can grow to over 35cm wide, and come in shades of red, orange, brown and beige.

Group with knobbly
And here's our traditional shot with the knobbly!

Fluted Giant Clam (Tridacna squamosa)
At the reef edge, we visited our resident Fluted Giant Clam (Tridacna squamosa). This clam feeds on plankton and tiny organic particles in the water. At the same time, it harbours symbiotic algae in its body. The algae photosynthesizes and pass on some of the food to the clam, and in return gain shelter and protection.

Funeral Nudibranch (Jorunna funebris)
We saw several nudibranchs, and here's another one - a Funeral Nudibranch (Jorunna funebris).

I guess all in all, we were still rather lucky to have seen so many interesting things despite the rain.

One the day before this, we had a survey trip on Semakau too, and we had a scorching sun instead of the rainy weather.

Just to highlight three of the special things we saw:

Sap-sucking slug (Plakobranchus sp.)
I found this very pretty sap-sucking slug, a Plakobranchus sp. This is the first time that we saw this on Semakau.

Forskal's Sidegill Slug (Pleurobranchus forskalii)
Another new record for the intertidal area of Semakau will be this Forskal's Sidegill Slug (Pleurobranchus forskalii). According to the Nudibranch Encyclopedia, this slug feeds on ascidians.

Spotted-tail Frogfish (Lophiocharon  trisignatus)
While we regularly see the Spotted-tail Frogfish (Lophiocharon trisignatus), it was so cute that I decided to still include it here.

It was a great weekend on the whole. Looking forward to find more new things next month... :)