Slugs galore at Pulau Jong

We had a rain-free day at Pulau Jong this morning! And there were lots of beautiful sea slugs!

It's such a joy to be able to take a landscape photo of the charming Pulau Jong with bright sunlight shining on it. Simply because all of my previous 3 trips (latest was 2 years ago) to this island were associated with rain. 

New star find at Pulau Jong

A new star was found at Pulau Jong today! Chay Hoon found it among the seaweeds!


This tiny sea star has 7 legs! And it was a mottled coloration consisting of speckles of purple and red on its upper surface. The edge of the star is orange-fringed.

Back to Jong!

Yes, I'm back to Pulau Jong, one of the smallest island in Singapore. Supposed to go Tanah Merah today but during the last minute, Ron told me there's a boat space so here I am to my most favourite island of Singapore.


Why is this island my most favourite out of the numerous in Singapore? Because it is uninhabited, untouched and most important it has such a spectacular natural coastal landform!


Unfortunately, when we arrived there in the morning, the ominous clouds emerged from the southwest and covered the entire area! Thus, it was a long wait before the clouds cleared. Thank God that the second wave of rain and lightning did not head out to Jong and thus we could land on Jong.


Soon, the sun returned and one will be amazed to see that the intertidal area is many times bigger than the island itself! It is like a huge playground.


The reefs off Pulau Jong are well known to house both abundant and diverse number of soft corals. It is amazing that such beautiful coral reef exist in the middle of the surrounding petrochemical plants at Pulau Sebarok, Pulau Bukom and the landfill at Semakau (background of this photograph).


Different species of soft corals come in different sizes and patterns.


This one is what we usually call as the "dead man's finger" because it looks like many hands sticking out from the ground. Otherwise it is also called the smooth leathery coral (Family Alcyoniidae).


There are also soft corals like look like flowers, like this Asparagus flowery soft coral (Family Nephtheidae).


Strangely, it was mind boggling to find this smooth soft coral with neon yellow-green coloration on it. Is it bleaching, dying, or just another type of soft coral?


I went to check the maxima giant clam (Tridacna maxima) that was found during the trip last November. Yes this stunning clam is still there and still surrounded by soft corals. Though this time the tide was lower, this the mantle was less exposed to prevent dessication and stress.


OK, so there are many soft corals. Ah this seems to be a hard coral. Actually not! The Blue coral (Heliopora coerulea) in this photo is actually not a hard coral. Despite producing a hard skeleton, these corals are more closely related to soft corals. Blue corals are considered living relicts of fossil species known from more than 100 million years ago.


The blue coral is named this way because its internal skeleton is blue while the outside looks mostly brown in colour. Still, I managed to find this colony with blue coloration.


Sometimes, the blue coral can be home to Banded fan worm. Here you see that the blue coral is not blue.

Quite confusing right? Not blue, but called blue coral. Not soft, but is not a hard coral. Haha!


OK finally the real hard coral thing. The pinkish coral beside the blue coral is a hard coral that is probably the Boulder pore coral (Porites sp.). Think it's my first time seeing it pink.


This starry and flurry pretty coral is actually the Cauliflower coral (Pocillopora sp.).


And I also came across two colonies of this Acropora coral (Acropora sp.). When underwater, their tentacles are extended and look very beautiful.


Another coral with nice polyp tentacles sticking out will be the Disk corals (Turbinaria sp.) where individual corallites are actually quite well spaced apart.


Of course there are also many of the more commonly seen faviid coral (Family Faviidae) that have neon green colours.

Enough of corals?


Here's something else.... a jellyfish that I spotted when I first landed at Jong.


Siyang found this Mosaic reef crab (Lophozozymus pictor). Despite looking yummy, since it is red, it is the most poisonous crab in Singapore!


I stumbled upon this anemone which I am unsure of its identity. It does look similar to the Frilly anemones (Phymanthus sp.).


Jong today was a disappointment to me, being an echinoderm fan. Couldn't find the cushion star. Instead, there are plentiful of this Black long sea cucumber (Holothuria leucospilota). No more other echinoderms already, though Ron saw the stonefish sea cucumber (Actinopyga lecanora).

Nevertheless, this island has quite a fair variety of nudibranchs!


Like this Phyllid nudibranch (Phyllidiella pustulosa).


I also found three Black-margined nudibranch (Glossodoris atromarginata). WHERE is the the third one? The third one is actually beneath the right hand side nudi, possibly mating was in the process. Can you see a fringe of darker yellow behind? That's the third one.


The Hairy green seaweed (Bryopsis sp.) in Jong is home to many slugs like this Polka-dot nudibranch (Jorunna funebris).


Another slug that can be found in seaweeds will be this tiny wenny Dermatobranchus nudibranch (Dermatobranchus sp.). It was most difficult to photograph in the seaweed given the strong wind and waves today where the seaweed was swaying nonstop!


This is another tiny slug with the seaweed and it is Thuridilla gracilis (Thanks Siyang for the id).


And one more really tiny slug... All these slugs were challenging to photograph... but it's good to know that seaweed are good homes to these creatures.


Time past so fast and we had to leave the island before getting trapped with the incoming tides. See you next time Jong!

Maxima giant clam at Jong

I finally got to visit Pulau Jong! It is the PAU (bun) island that we always see from the boat whenever it passes by to Semakau.

According to a local legend behind the island's name, a Chinese junk was attacked by Malay pirates one night where the island now is. Just as the pirates were about to board the junk, the captain awoke. When the captain saw the pirates, he uttered such a frightful yell that the sea spirit turned the whole junk into an island.

This small looking island is not just a piece on land with forest, but during low tide you can see its reef extending outwards.

In fact, it is a very charming island in my own opinion with its shape and coastal landforms.

It has natural caves that are carved out when waves hit against the lower resistance portion of the rock formation. You can see the fault lines also very clearly. Like the cliffs at Tanjong Rimau of Sentosa, the formation is pinkish because of iron. It reacts with sea water and result in iron oxide which give it the pinkish reddish glow.

On these magnificient natural cliffs are many types of coastal plants.

And there is one that has purple fruits though I have no idea what is it.

Other coastal plants you can find at Pulau Jong include this seashore pandan.

And also the sea lettuce.

I always cannot resist not taking photographs of the white flowers of the sea lettuce.

On the rocky shores, life is teeming! Each black spot is actually a snail!

Among the many snails and nerites you can find at the high shore, there is this beautiful nerite that is pink with patterns on it.

By looking at the underside, Ria knows the id, which I cannot remember the scientific name already by now.

There are also top shells found at the rocky area.

Instead of the usual egg crabs, the red eyed reef crab is quite common at Jong.

Not forgetting the flora portion, we also saw a couple of seagrass species including this spoon seagrass.

However echinoderms are not too common here, except for the black sea cucumber which are numerous on the Jong-ky shore.

Nevertheless I saw this leafy slug beside two of the black sea cucumbers.

I didn't get to see many nudibranches though except for this polka dot nudi. Later, Chay Hoon shares with us that there are very tiny Gymnodoris slugs on the seaweed which I gave up photographing without trying given my camera's not too excellent macro. Mei Lin got a good shot though, and I hope she can share with us soon.

If you ask us what is most prominent and significant in Pulau Jong, we will reply in unison, "Soft corals!".

Indeed there are MANY large soft corals around the intertidal reef area of Jong. Much more than their hard corals. If you ask why, I personally feel perhaps it's due to the stronger currents??

Just beside another large patch of soft corals, Ria found something special! Can you spot it?

It's an adult giant clam of about 30cm in length! When opened in water, the colourful mantle looks really gorgeous! It's great to have Mei Lin (aka "giant clam girl") to be with us as we get to also somehow see giant clams. Click here to see her pretty face at the Wildshores of Singapore blog.

This girl told us that this is most likely Tridacna maxima which we intertidal people have never seen before (or got it properly identified). The previous sighting was at Raffles Lighthouse during diving in 2003. Now, we are the fortunate few to be able to see it!! Wow!

Next, we had a tough task trying to identify whether it is the elusive T. maxima. Here's the diferent parts that were analyzed to check its identity.

We had to check for its structural makeup and found out that this giant clam has closely stacked and small scutes (fluted projections out from the shell surface) in contrast to the more commonly sighted T. squamosa that we see at Semakau and other southern shores. Also, the surface area of the mantle looks more elongated. This is true because the common name of T. maxima is elongated giant clam.

With the double confirmation by Dr. Peter Todd and Karenne Tun from Marine Biology Lab, NUS, indeed this is the second living elongated giant clam found in our very own local waters (the other at Raffles Lighthouse).

Becauses surveys of our water are not intensive and due to possible misidentification of giant clams, we might have more of this T. maxima which is wonderful!

Below are more photos of this fascinating giant clam.

This is the excurrent siphon which is to clear their excretory products. Mei Lin is studying whether these siphons can probably also aim and squirt water at predators. Indeed, Andy was squirted when he tried to video the clam.

How then can they know that there are predators? This is because they can see! Look closely and you can see the eye spots of the giant clam in this photo (clue: look for the tiny spots at the top).

The giant clams are more colourful than you think. The underside of the mantle can be bright yellow or green, and there's a hint of it from this photo.

I still can't believe that we saw this fascinating giant clam! Yea, finally we can declare that we have seen all the three giant clam species in Singapore intertidally.

And it's so coincidental that when Mei Lin first joined us for southern shore trips, we get to see this rare giant clam that she can helped to find its identification.