Sentosa's Tanjong Rimau

Visited Sentosa's Tanjong Rimau few times recently, so this is just a summary blog of the things I saw. Unknown to many Singaporeans, Sentosa has a natural underwater world not too far away from its man-made underwater world! :)


Tiny little Costasiella Sea Slug (Costasiella sp.) less than 5mm long that was found on the Fan Seaweed (Avrainvillea sp.). They were rather numerous, and on of of the seaweed, I actually found about 10 of them.


When I told KS that I was going to Sentosa, he commented that CH found a Galloping Sand Star (Stellaster equestris) some time back, and I might see one. I told him that my luck had not been fantastic these days, so I doubt I would see one. But surprise surprise! Thanks to his golden mouth, I really saw one this morning! While I have seen this before at Semakau, it's still really nice to see it again here on Sentosa :)


Hen spotted a juvenile Cushion Star (Culcita novaeguineae) - my first time seeing it here on Sentosa too!


At the sandier area, there were lots of Sand Dollars (Arachnoides placenta).


Since we reached the shore while it was still dark, there were lots of nocturnal animals, such as the many shrimps in the various tidal pools.


The crabs were out too, and the various species of swimming crabs (Family Portunidae) were the most numerous. This is probably a Thalamita pelsarti.


There were many juvenile swimming crabs too.


Among the branching Montipora corals, there were several Smooth Spooner Crabs (Etisus laevimanus). These crabs use their claw's flattened tips to scrape algae to feed on.


A few Purple Climber Crabs (Metopograpsus sp.) were seen crawling over the rocks. They have claw-like legs which aid them in their climbing.


There were many tiny hermit crabs, which I have no idea what species they are.


There was this little Estuarine Moray (Gymnothorax tile) slithering around, probably searching for smaller animals to feed on.


On one of the trips, we saw a black frogfish! My guess is that it is a Spotted-tail Frogfish (Lophiocharon trisignatus) in its black phase.


Moving on to the sessile animals, I saw a number of sponges appearing rather sick, and probably dying or dead... They turned greyish-black in colour, and appeared to be disintegrating.


Some of the corals had a rather sickly colour too.


There were a number of bleached corals here and there, but guess there's little we can do about such a situation except to blog and spread awareness.


Most of the corals appear rather healthy though, such as the Turban Coral (Turbinaria sp.) above.


There were a few colonies of Acropora corals, and I was rather surprised to see them as the water was really murky, and Acropora mostly require clear and pristine water to do well.


There were a number of interesting plants at Tanjong Rimau too, such as this Raffles' Pitcher-Plant (Nepenthes rafflesiana).


There were at least 3 locally critically endangered Xylocarpus rumphii at Tanjong Rimau. On mainland Singapore, I have only seen naturally occurring ones at Sungei Buloh, though I understand they can also be found at Pandan Mangrove. Offshore, apart from Sentosa, they can also be found on St John's Island.


Apart from the wildlife, Tanjong Rimau also has majestic cliffs to offer!


There were quite a few natural caves too!

So apart from being a nice place to show biology students about our marine life, it is also a great place for geography students to learn about coastal landforms :P

Sentosa's Real Underwater World

Went to Sentosa to visit its real and natural underwater world on Tuesday, 23 Jun, and did not had the time to blog until today. It's been a really busy week. So here's just a quick listing of some of the things we saw.


This little Flatworm is quite commonly spotted on our shores.


A Smooth Spooner Crab (Etisus laevimanus) which feeds on algae by scraping them off rocks with its pincers which have spoon-like tips.


Pretty little nudibranchs - Dendrodoris denisoni.


There were lots of Gobies which I did not had the time to find out the ID.


Spotted a few Mantis Shrimps, and here's one of them.


A huge coral garden...


I also found several Kite Butterflyfish (Parachaetodon ocellatus).


It was nice seeing this little Pygmy Squid (Idiosepius sp.) which was not camera-shy at all.


A rather huge Barrel Sponge (Xestospongia testudinaria).


A very aggressive Red Swimming Crab (Thalamita spinimana).


We even found several Snake Eels (Pisodonophis crancrivorous), and here's one of them.


Here's a close-up.


Keyhole Limpet with a little crab.


A pair of Glossodoris atromarginata nudibranchs.


A very huge Flatworm about the length of my palm!


There were lots of Sand Dollars (Arachnoides placenta) at the sandy area.


There were at least 3 Xylopcarpus rumphii trees on this shore, and here're two of them.


Lots of Raffles' Pitcher Plants (Nepenthes rafflesiana) can be seen hanging off trees.


And of course, I always visit the Tongkat Ali plant (Eurycoma longifolia) whenever I visit this area.


My favourite shot of the day - a Black Carpenter Bee (Xylocopa latipes) in flight. Was rather surprised that my simple point-and-shoot camera managed to capture this shot :P

Sentosa on 27 Jan 2009

It's been a while since I last visit the shores of Sentosa, and so on Lunar New Year Day 2, LK, ST and I decided to visit this little island. Tide wasn't really very low, and so I didn't really expect to see many things. But guess I was wrong :)


One of the things that kept drawing me back to Sentosa are the beautiful coastal landforms - spectacular cliffs, pretty arches, mysterious caves... You can find all of these at the rocky shore.


Signs of erosion at the shore, where the softer rocks were eroded and swept away by the waves, and the remaining harder rocks forming parallel ridges.


The last time I was here, there was a landslide on this slope. Some kind of reinforcement concrete has been built since then to ensure the slope will not slide down again.


On the sandy shore, I found a little sand-sifting sea star (Archaster typicus). This is a rather common sea star, and we have seen it on many of our southern islands, sometimes in the hundreds.


There were several huge carpet anemones (Stichodactyla haddoni). These are animals with lots of sticky tentacles to capture their prey, such as little fishes or crabs.


Sponges were a common sight here too. These are also animals, and they feed by filtering for tiny food particles in the water sucked in through little pores on their body. The sponge above is Pseudoceratina purpurea.


Some sponges may look like seaweeds or even hard corals, like the Lamellodysidea herbacea sponge above. You can tell them apart from the pores and that they usually do not have a hard skeleton.


And here are the real corals - the branching Montipora hard corals, growing among colonies of green ascidians.


Hard corals come in various growth form, and some may look like somewhat plate-like or flower-like, like the Turbinaria coral above.


Others, like the Porites coral, may look like a rock.


But if you look closer, you will realised that they all have little holes on them, and that's where all the coral animals, called polyps, live. The coral is basically like a HDB flat with lots of little occupants! Sometimes, corals may also fluoresce. This is due to their colour pigment, which supposedly helps prevent them from getting dun-burned.


While most corals are attached to the substrate, there are some, like the boomerang mushroom coral (Herpolitha limax), which are free-living.


Not all corals are hard - we have soft corals too! Sentosa is also a good place to find huge colonies of soft corals. The above is a Lobophyton sp.


While the corals are often mistaken for plants, here are the real plants - tape seagrass (Enhalus acoroides). Note that I'm refering to the long ribbon-like ones, not the hairy ones. Those are Bryopsis green algae.


It appears that there is a Bryopsis algal bloom, and we can see them every where. But among the green patches, there were a few red patches of red Halymenia algae too. Kind of an auspicious colour for the Lunar New Year :P


This giant reef worm (Eunice aphroditois) gave me a surprise when it suddenly appeared next to my feet. And of course, I immediately turned my camera towards it. Unfortunately, its head was hidden under the algae though.


Other interesting animals I spotted and remembered to take a photo include this little dendrodoris nudibranch (Dendrodoris denisoni). It was sliding over the sandy substrate when I spotted it.


There were quite a few funeral nudibranchs (Jorunna funebris) among the seaweed too.


At the rocky area, I found this giant top shell (Trochus niloticus). This huge snail feeds on algae.

All too soon, the tide was rising and we had to leave the intertidal area. On the whole, it was quite a relief to find the intertidal area still doing fairly well despite the development work been carried out in the surrounding areas. Will probably visit this shore again during a lower tide.