Exploring Pulau Jong - the Boat Island

This is quite a long overdue post. Didn't quite have the time to start writing it, due to the various guided walks I had last week, and I always give priority to blogging guided walks so that my participants will get to see it fast.

A few of us RMBR volunteers went to this little island, Pulau Jong, on 30 Apr. Pulau Jong, otherwise also known as the Junk Island, is located about 6km off the southern coast of Singapore.


I always thought it looks like a "pau", i.e. Chinese bun, from afar :P

We always pass by this island on our way to Pulau Semakau, but this was only my 3rd trip on it. Legend has it that a Chinese junk was attacked by Malay pirates one night at where the island is currently located, and as the pirates were about to board the junk, the captain woke up and on seeing them, gave such a loud scream that the sea spirit turned the whole junk into an island.


The sky was dark when we reached the island. As you can see, it is very near to Pulau Semakau behind. A thunder storm soon hit us, and RH, SY and I who got onto the island first had to hide in a little cave, while the rest waited on the boat.


The sky soon cleared after a while, and the rest also got onto the island on a little dinghy.


What I liked best about Pulau Jong was the lots and lots of pretty soft corals in the huge tidal pools! The above shows several colonies of Toadstool Leather Coral (Sarcophyton sp.). These soft corals have symbiotic algae (aka zooxanthellae) which photosynthesize and provide them with most of the nutrients they require, though they are filter feeders and can filter for plankton from the water too. Some of the species produce toxins which can be harmful to surrounding organisms, thus ensuring that they will have sufficient space for growth.


There were many colonies of Lobed Leather Coral (Lobophytum sp.) too. Like the Toadstool Leather Coral, they too harbour zooxanthellae.


The above are the Dead Men's Fingers (probably Sinularia sp., but some Lobophytum sp. could look very similar too). Imagine looking at these corals swaying with the waves - they will look just like fingers waving at you!


Related to the soft corals are the sea anemones, and we saw this pretty yellow Branched Sea Anemone (Phymanthus sp.) not too long after we started our exploration. Sea anemones have stinging tentacles to catch small animals.


And not too far away from the anemone was another stinging animal -jellyfish!


We walked further out, and KS brought us to see a Maxima Giant Clam (Tridacna maxima) he saw during a previous trip.


Talking about giants, we saw several Giant Top Shell (Trochus niloticus) at the rocky shore too. This huge shell is often collected for food in the neighbouring countries. The shell is also polished and made into buttons and jewellery.


Jong has always been a great place to find slugs. Despite the strong wind creating a lot of ripples, which made it really difficult to spot things, we still managed to find quite a few slugs, including 3 Black-margined Nudibranchs (Glossodoris atromarginata).


This is a Pustulosed Phyllid Nudibranch (Phyllidiella pustulosa). Slugs from this family are able to release powerful toxins into the surrounding water when they are stressed. They feed on sponges.


The Dermatobranchus Nudibranch (Dermatobranchus sp.) appears to be in season, and were every where! Nudibranchs from this genus usually feed on soft corals.


We also found several small Sap-sucking Slugs (Order Sacoglossa), which we all had a hard time trying to take good photos of them since they were so tiny! These slugs are able to store the chloroplast from the sap that they have sucked from the algae, and use them for photosynthesis!


Another sap-sucker I found was this Thuridilla gracilis.


Several crabs were also spotted. This Mosaic Crab (Lophozozymus pictor) is the most poisonous crab in Singapore, and the toxins will not be destroyed even after you cooked it.


A Spotted-belly Crab (Ozius guttatus) was hiding in a hole among the rocks when we found it.


There were lots of Red-eyed Reef Crabs (Eriphia ferox) on the rocky shore, and they can be quite aggressive!


Like other rocky shores in our other southern shores, there were quite a number of Black Sea Cucumbers (Holothuria leucospilota). This sea cucumber will eject sticky white threads from its backend when it is stressed, a defence mechanism to confuse its predator.


Another sea cucumber we saw was the Stonefish Sea Cucumber (Actinopyga lecanora). This sea cucumber is usually found among the coral rubble, and can really blend into the surrounding with its speckled pattern!

Soon, the tide was rising and we had to leave. This was again a really great trip, and I was glad that I was able to visit this little island again! :)

Coral Garden on Pulau Jong

It's been almost a year since I last visited Pulau Jong, and so I was really looking forward to this wildfilms and sponge gang trip :)

One of the most amazing thing about Jong was perhaps the soft corals - there were just so many of them, not just in the number of colonies, but in the number of species too!



The whole lagoon in the middle of the intertidal zone was like a soft coral garden.

And among the soft corals, there were lots of hard corals too!



For one thing, the water in the lagoon was exceptionally clear, and thus we were able to get really nice and clear photos.

But corals were not the only wildlife that Jong can offer.



I've seen the above on several of our shores, but never knew whether it's a seaweed or a sponge. It was only recently that I heard from Chee Kong that this is probably a sponge.

There were also lots of anemones on Jong.



The above is probably a Condylactis sp.



I also found several bulb tentacle anemones, and one of them actually had tomato anemonefishes! But this time round, I couldn't spare the time to wait for for a good shot of the anemonefishes, unlike the time when we were at Hantu.

These days I seemed to have quite a bit of nemo luck though.



I have seen the ocellaris clownfish on all my last 5 southern island trips!

While the ocellaris clownfish was really pretty and cute, I also encountered another just as pretty fish, but not exactly that cute at all.



The blue-spotted fantail ray. Last year when I was at Jong, I saw a huge blue-spotted fantail ray at least 40-50cm wide. Was really hoping to see one again today, but while I didn't managed to find it, Helen spotted one!



There were lots of crabs on Jong too. The above is the poisonous brown egg crab. Eat it, and you may have to say an early good-bye to your family and friends.

And let's not forget the slugs! The marginated glossodoris nudibranchs were every where, and I lost count of how many I saw.



There were several black phyllid nudibranchs (below left) and lots of pustulose phyllid nudibranchs (below right) as well.



I also saw a few sea cucumbers - black sea cucumber (below left) and the stonefish sea cucumber (below right).



Sea cucumbers are related to sea stars, and during my trip here last year, I remember seeing a cushion star.



I was searching high and low for it, and finally managed to find one when we were about to pack up and go.

And here's my find for the day.



Just imagine the shell above in the coral rubble - it was really a master of camouflage.

Turning it over, I saw that it has 2 little eyes and a long trapdoor (aka operculum).



It is a conch! But I've never seen such a conch before! Saw in the Wildfilms blog that eventually, Ria managed to check with Dr Tan Koh Siang who was with us, and he said this was actually a juvenile spider conch!



Here's an adult spider conch we found today. Seems like they only grow the spines when they are older.

Soon, the tide was rising , and we had to leave. Hopefully I'll have the opportunity to come back here again!