Rained Out at Chek Jawa

Last Thursday, I finally managed to squeeze out some time to go Chek Jawa to guide at the public walk. It felt really good to be back here again, especially when I had been really busy and had not been able to guide here since April this year.


Here's the group assigned to me.


We started with the mangrove boardwalk, and saw several interesting plants such as the nipah palm (Nypa fruticans). What you are seeing are the flowers. The attap chee used in local desserts like the ice kacang come from the fruit of this palm. During my kampong days, the house I lived in had roofs made from attap leaves, so seeing this palm always bring back the good old memories.


We also saw many crabs in the mangrove, such as the tree-climbing crab above (Episesarma sp.). Also called vinegar crabs, these crabs are edible and are pickled in black vinegar by the Teochews. We also saw many different species of mudskippers.


Here's a look at the mangrove habitat. Many mangrove trees have roots exposed to the air as the soil is very poor in oxygen. These exposed roots will help the trees to breathe better. The roots are usually spread over a wide area too, helping the trees to balance themselves on the soft mud.


We eventually reached the intertidal area, but to get onto it, we had to climb down a little ladder.


Here's an orange striped hermit crab (Clibanarius infraspinatus). It's rather common at Chek Jawa. Unlike true crabs with a hard exoskeleton covering their whole body, hermit crabs have a soft abdomen, which is why they need to live in an empty shell for protection. A few slipper snails (Crepidula walshii) live inside the shell with the hermit crab. they are the flattish, white coloured stuff on the shell behind the hermit crab.


There were several clumps of green mussels (Perna viridis) on the sandy shore too.


This was the first time many of them saw a living sea cucumber! The one above on the child's palm was a ball sea cucumber (Phyllophorus sp.). The Malays made a traditional tonic called Air Gamat from the body fluids of this sea cucumber, which is used to help the healing of wounds and as a post-natal treatment.


I was rather glad to see that the resident Haddon's carpet anemone (Stichodactyla haddoni) was still there.


I found several cake sand dollars (Arachnoides placenta) near the anemone. These are animals related to the sea cucumber and sea urchins.


The hunter-seekers also found us a big sea hare which we often encounter on our northern shore. It looked somewhat like the geographic sea hare, but did not have some of the usual features, and so we were still not sure what's its exact ID.


Then all of a sudden, the sky poured on us! Many of us were drenched even though we had out umbrellas and poncho. The wind was just too strong and the rain too heavy. We had to get out of the intertidal area immediately.


It was just rather funny to see Adelle holding the sign "This is too much, too wonderful!". There were certainly too much rain and wind, but wonderful or not was really rather subjective. Haha. I must say it's rather fun to be rained out once in a while though :P


The visitors went to the nearest shelter as the rain was just too heavy.


And it turned out to be a blessing in disguise for not returning to the Chek Jawa Information Centre immediately, because we spotted 3 otters swimming in the sea nearby! The rain was too heavy and it was too dark and far for me to take any decent photos though.

It was rather unfortunate that we couldn't complete our guided walk, but still, it was a really exciting trip for many of us!:)

Overnite at St John's

It's another low tide weekend, and we decided to go to St John's Island and spent a night at the Tropical Marine Science Institute.


Our first stop was the little patch of mangrove on the island.


There were lots of red berry snails (Sphaerassiminea miniata) on the muddy substrate.


And finally, we found what we were looking for - Api-api jambu (Avicennia marina), also commonly known as the grey mangrove or white mangrove. It is the rarest Avicennia species in Singapore, and this was only my second time seeing this plant locally.


Our next stop was the sandy shore, and we found lots of soldier crabs (Dotilla myctiroides) "marching" around on the sand.


And what's this lying on the sand? A seven-armed sand-sifting sea star (Archaster typicus)! My first time seeing one! Previously, I have only seen those with 4, 5 and 6 arms.


There was a Bryopsis agal bloom, and with the algae came its feeder - the leaf slug (Elysia ornata).


A spotted-tail frogfish (Lophiocharon trisignatus) was also found among the seagrass and seaweed.


St John's Island is one of those places which we can often find spider conches (Lambis lambis). These snails are very well-camouflaged, but once you turn it over, your can see its pretty coloration on its underside, the long trapdoor and the two cute little eyes.


When a spider conch dies, its shell is sometimes taken over by hermit crabs, such as this hairy hermit crab (probably Dardanus lagopodes), which we regularly spot on St John's.


As I was looking at the hermit crab, I suddenly noticed that a piece of dead coral nearby was moving. Picking it up, I saw this little crab inside. I have seen such crabs living in holes on dead coral pieces many times, but had not been able to found out what species they belong to.


This tiny little sap-sucking slug (Thuridilla gracilis), hardly more than 1cm long, was found by RH.


This blue-spotted fantail ray (Taeniura lymma) was not camera-shy at all, and hardly moved as we took our time to take photos of it.


There were lots of soft corals in the various tidal pools form during the low tide.


Corallimorphs were another common sight at St John's. Related to corals and anemones, they were sometimes also called mushroom anemones as they have a wide oral disc attached to the substrate by a thin stalk, making them looking like mushrooms.


Some how, there were far less hard corals these days at St John's Island, and we are not really sure why. Many died and the intertidal reef was replaced by coral rubble at most places along the rocky shore that we usually visit. The blue corals (Heliopora sp.) seemed to be doing well though. The above photos show a few mushroom corals (Fungia sp.) among the blue corals.


Can you spot the octopus above?


This pretty flatworm (Pseudobiceros bedfordi) was swimming near the water surface when I spotted it.


I also found this nudibranch, probably a Discodoris lilacina.


As the tide eventually gone higher, we headed back to dry land and found the sea poison tree (Barringtonia asiatica) blooming.


A few land hermit crabs (Coenobita sp.) were also out and about.


On the next morning when we were at the jetty to take the ferry back, we noticed that the tide was ultra high! Wonder if it will overflow onto the jetty after we left the island. Hmm...