Chek Jawa Walk on 16 Dec 2009

This is again a rather long overdue post :P

Anyway, was back at Chek Jawa to help out with guiding. This time round, I had a group of family and friends again. It was always nice seeing family groups with little kids, and the parents trying to expose their children to the wild side of Singapore!


As usual, we started with the mangrove boardwalk. The visitors were rather impressed when they saw the huge sizes of the Nipah Palm (Nypa fruticans) fruits! These were basically a cluster of seeds, and within each seed was an edible "attap chee" that you could find in local desserts like the ice kacang.


Many of the Nipah Palm trees are flowering too. The long bushy stalks were the male flowers, while the ball-like structure which looked like a miniature fruit was the female flower. Some people actually cut the flower stalk to collect the sap to make into palm sugar (gula apong).


In the mangrove, we saw quite a few Giant Mudskippers (Periophthalmodon schlosseri) too. These fish were rather aggressive hunters of small animals. Their fins below were modified into a sucker-like structure which allowed them to skip quickly on the muddy ground and climb up rocks and branches to get their prey or escape from predators.


We eventually reached the intertidal area, and among the first animals we saw was this Mangrove Horseshoe Crab (Carcinoscopius rotundicauda). Horseshoe crabs are very ancient animals, and their body plan has hardly change over 400 million years!


There were lots of bivalves on the shore, including these Green Mussels (Perna viridis). These mussels were very common on our northern shores. During low tide, they would close their shells tightly to prevent water loss. But as the tide rose, they will emerge to feed on tiny food particles in the water.


I came across this Sand-sifting Sea Star (Archaster typicus) along the way while bringing my group to another station. As the name suggests, this sea star can burrow into the sand, and sift for tiny food particles.


This Thunder Crab (Myomenippe hardwickii) was a really strong fellow, and refused to let go of the plastic container. According to local beliefs, when this crab pinches someone, it will only let go when it hears a clab of thunder. While this is a very aggressive and stubborn crab, it will usually let go after a while as long as it does not feel threatened.


We were quite lucky to came across this huge Noble Volute (Cymbiola nobilis). This pretty snail is unfortunately collected for food in some areas.


When a noble volute dies, its shell may be taken by animals for shelter, such as this Orange Striped Hermit Crab (Clibanarius infraspinatus). Unlike true crabs which are well-covered by a hard exoskeleton, hermit crabs have a soft abdomen, and thus need to seek shelter in an empty shell.


Our other volunteers manage to find us a few Biscuit Sea Stars (Goniodiscaster scaber), and here's one of them. We gave it this common name as it has a very regular star shape. and appear as if it was cut out with a cookie cutter.


There was also a lonely Striped Eeltail Catfishes (Plotosus lineatus). It has venomous spines and can sting very painfully.


The Pink Thorny Sea Cucumber (Colochirus quadrangularis) appeared to be in season, and we saw many of them. This sea cucumber collects tiny food particles in the water to feed on.


There was a Sand Star (Astropecten sp.) too. Unlike the Sand-sifting Sea Star, this is a predator and feeds on small snails and clams.


One of the volunteers found this Three-spined Toadfish (Batrachomoeus trispinosus). This fish will croak like a toad when it's stressed. It has venomous spines though, and can give painful stings.


We found these barnacles growing on the back of a crab. The feather-like structures are actually the "hairy legs" of the barnacles, which are used to create water currents to collect tiny food particles from the water.


As we were heading back, we saw another Noble Volute, but this one was laying eggs! The eggs will eventually hatch into little snails.


There were quite a few Sandfish Sea Cucumbers (Holothuria scabra) too. This is the sea cucumber that we normally find in restaurants, but note that they must be properly processed to remove toxins in them before they can be consumed.


There were quite a few Haddon's Carpet Anemones (Stichodactyla haddoni) on the sand bar, though not as many as what we had before the mass death.


And here's a photo of my group.

Really fortunate that although it rained a little at the beginning, the weather held and we managed to complete our walk!

Mangrove Lime (Merope angulata) at Mandai Mangrove

I have been really busy for the past few weeks, and thus was really glad to have a break to explore Mandai Mangrove today with LK and MC.

And the biggest surprise of this trip must be this!


We were exploring around when I saw this bush which looked somewhat familiar...


I decided to take a closer look. And yes indeed, it's what I thought it was - a Mangrove Lime (Merope angulata)! Although it was stated in the "Guide to Mangroves of Singapore" that it can be found here, I did not really expect to see one so easily. In fact, my main objective here was to search for the Kacang Kacang (Aegiceras corniculatum), which I had a photo of the fruits at Ubin previously, but before I managed to get some shots of the flowers, the tree was bulldozed...

Anyway, (Merope angulata) is a rather rare mangrove associate in Singapore, and even many of my friends have not seen it before! Can't remember where I last saw it though... could be Sungei Buloh or Kranji...


According to "Mangrove Guidebook for Southeast Asia", Merope angulata (from the lime family Rutaceae) is a broadly-branching, shrubby, occasionally scrambling, low tree, up to 3 m tall. It has (often paired) woody spines located in the axils and the alternate, thickly leathery, aromatic leaves have transparent dots.

The leaves are covered with minute glands (visible as translucent dots when held to the light) and have a resinous, lime-like odour if bruised. The flowers are white and bisexual, while the ripe fruits are yellow, and are oblong or ovoid triangular in shape with 3 flattened sides so that the fruit is triangular in cross-section. Within the fruit are 3 chambers which each contain 1 large, long, flattened seed.

This plant is used to treat abdominal complaints and assist womb contraction after childbirth.


According to my mum, there were a few of these shrubs at my grandma's old house at Punggol last time. (No wonder I always find it to be rather familiar. Those good old days...) My mum used to pluck the fruits to eat, though they are rather sour. Sometimes, they also dried the fruits, and chewed them.

As we went on exploring, we found 2 other trees! Unfortunately, we did not really get to further explore much as the sky was turning really dark, and we had to leave, even before finding the Kacang Kacang that I had wanted to find...

But within the short time that we had, we still managed to see a few interesting things along the way...


We also found a young Ipil (Intsia bijuga). According to "Mangrove Guidebook for Southeast Asia", this deciduous tree can grow up to 40m tall! This tree has very hard and good quality timber that is very durable, resistant to insects and weather. It is often used for building houses (especially house posts) and bridges. Very durable, resistant to insects and weather. The bark and leaves are used as medicine to treat diarrhoea. The seeds are fried, soaked for 3-4 days, then boiled and eaten.


Here's a look at the mangrove habitat at Mandai.


We also found a huge patch of Beccari's seagrass (Halophila beccarii). This seagrass is said to be rather rare, though sometimes I do wonder if the researchers have been looking at the wrong type of habitats. It can be found in several mangroves in Singapore, and I will assume they can probably be found in many of the mangroves in the region. But of course, I am no expert so I could be wrong...


We came across this blooming Caesalpinia crista. The seeds are supposedly used as marbles by children, and are also used to treat malaria and parasitic worms. The leaves are used to treat Hepatitis A.


There were patches of Sea Holly. This is Acanthus ilicifolius with the pretty purple flowers.


It appeared that some students were doing some research project here, and we saw several flowers of the Tumu Merah (Bruguiera gymnorhiza) being tagged.


We found a lot of Face-banded Crabs. The above is probably a Perisesarma eumolpe.


This one has a yellow face, so I am not really sure what species it is.


There were lots of Orange Signaller Crabs (Metaplax elegans) too, but they were really hard to take photos as they were really shy... The male crabs wave their orange claws to attract females, and hence the common name.


Like other mangrove areas, there were lots of clams here too. The above is probably a Lokan (Geloina sp.). They were collected in the region for food.


We also saw this little Mangrove Horseshoe Crab (Carcinoscorpius rotundicauda). The roe of the females are said to be very toxic, and can be lethal when consumed.


On the way out, we saw this pretty Oriental Whip Snake (Ahaetulla prasina). Learned from MC that to tell it apart from the Big Eye Green Whip Snake (Ahaetulla mycterizans), just look out for the yellow line running by the sides of its belly.


And then came a train, and the rumbling probably disturbed the snake so much that it moved further up the tree until we lost sight of it...

It was certainly a good trip, even though we had rather little time here due to the weather. It started raining when we were washing up. I would certainly want to visit this mangrove again. Hopefully to find the Kacang Kacang, and also, to get some photos of the ripe Mangrove Lime fruits.

Last Project Semakau Survey of the Year 2009

It's the last survey of the year for Project Semakau. This time round, I was doing the coordination work which involves a lot of running around. Thus, as usual, I wasn't able to take many photos. Still, it was a really good trip with several interesting finds, and here are some of the things that I managed to steal time to take some photos...


The Banded File Snake (Acrochordus granulatus) is a rather harmless non-venomous snake. It got its name from the rough skin it has, which allows it to hold tightly to small prey like a fish as it constricts the latter.


Not too far from where I found the file snake, I spotted this Estuarine Moray (Gymnothorax tile). This eel is often sold in the aquarium trade. It is mostly found in brackish water or coral reef near the shore.


A pair of Manrove Horseshoe Crabs (Carcinoscorpius rotundicauda) was found at the sandy area near the edge of the mangrove. The roe of this horseshoe crab is said to be very poisonous and can even caused death when consumed.


A group of Knobbly Sea Stars (Protoreaster nodosus) seemed to have moved further to the right side of the reef. Here's one of them.


We saw so many Red Swimming Crab (Thalamita spinimana) that I totally lost count of them.


The Stonefish Sea Cucumbers (Actinopyga lecanora) were also out in full force! I saw at least 10 of them over a small stretch at the reef edge.


The Stonefish Sea Cucumbers come in a variety of patterns, and the patterns on this one is certainly very different from the previous one.


A night survey usually also means that we will see lots of octopuses!


And squids too! These are Bigfin Reef Squids (Sepioteuthius sp.). We can usually see many of them on a night trip.


These are the same pair of squids, and you can see that their patterns have changed!

Soon, the survey ended, and after packing and consolidating the data forms and equipment, we took the boat back to mainland. Along the way, we looked at some of the mollusc specimens collected.


This is the Marginate Conch (Strombus marginatus), which we had also found on Semakau previously. Though not as abundant as the Gong Gong (Strombus turturella) or Black-lipped conch (Strombus urceus), it is still relatively easy to find this conch on many of our shores.


This other one here, however, was declared by our mollusc expert to be a rare find. Can't quite remember exactly what he said, so guess I'll have to confirm with him again next week before I update this page again :P

Chek Jawa Walk on 1 Dec 2009

Last Tuesday, I was back at Chek Jawa to help out with guiding for the public walk. Here are some of the photos taken during the trip.


When we reached the entrance to Chek Jawa, there was a troupe of long-tailed macaques (Macaca fascicularis) there. And much to my dismay, I saw one of them eating a packet of nasi lemak! While some visitors may find this to be cute, I personally felt that we should never feed wild animals, either deliberately or unintentionally. Please look after your food in a nature area, as once these wild animals got used to getting human food, they may eventually get into the habit of harassing humans for food. This may also result in them losing the ability to find food in the wild.


There was a wild boar (Sus scrofa) at the hut, and it was also eating some bread - human food again!

I eventually reached the info kiosk area, and was assigned to a group of family and friends.


As we were still early and the tide was still high, we decided to talk a walk along the mangrove boardwalk first. As usual, we saw lots of nipah palms (Nypa fruticans) bearing fruits. This is where you get your attap chee in your ice kacang!


As we passed by the 2 tumu putih (Bruguiera sexangula) planted by Nparks, I noticed a flower, and decided to take a photo of it. This mangrove plant was once thought to be extinct in Singapore, until several trees were found on Pulau Tekong. The young plants here at Chek Jawa were grown with seedlings from Tekong!


We soon reached the intertidal area, but to get down to it, we had to climb down some stairs.


And this was what we found at the base of the stairs - an orange striped hermit crab (Clibanarius infraspinatus)! It was a rather huge one, and was staying in a dead noble volute's shell. Unlike true crabs, hermit crabs have a soft abdomen, and need to hide it in empty snail shells to protect it.


One of the participants spotted this mantis shrimp! This shrimp has sharp spines on its claws for slashing and capturing small fishes and other animals.


I noticed a moving lump in the sand, and on brushing away the sand on top, this pretty moon snail (Polinices didyma). This snail feeds on other snails and clams.


Our hunter-seekers found us this sand-sifting sea star (Archaster typicus). Often mistake by aquarist to be an Astropecten species which preys on shells, this sea star actually feeds mostly on tiny organic particles among the sand.


Sand dollars (Arachnoides placenta) were really abundant here, and we had to be very careful so as not to step on any of them.


Unlike the noble volute (Cymbiola nobilis) shell we saw earlier with the hermit crab, this one was alive!


The hunter-seekers found this pair of juvenile kite butterflyfish (Parachaetodon ocellatus) in the seagrass meadow. Many marine animals lay their eggs among the seagrass and use the habitat like a nursery as there are lots of hiding places and food.


There was also an elbow crab. No prizes for guessing how it got its common name...


Gong gong (Strombus turturella) was one of the more commonly seen snails at Chek Jawa. It had a pair of cute little eyes to look out for danger as it hid in its shell.


There were several Haddon's Carpet Anemones (Stichodactlya haddoni) on the sand bar. This one prevented itself from drying up by holding a "pool" of water in the middle of its oral disc.


Ball sea cucumbers (Phyllophorus spp.) used to be really common previously, but these days we tend to see only 1 or 2 per trip. I guess they were still trying to recover from the flooding that happened a few years ago that brought in too much freshwater and killed many of them.


Pink thorny sea cucumbers (Colochirus quadrangularis) can be commonly found on most of our northern shores. They appear to be somewhat seasonal though, as there are times when I see lots and lots of them, but just a few at other times.


The visitors were quite delighted to see another sea star, this time round a biscuit sea star (Goniodiscaster scaber).


There was even a little pufferfish!


We found this sandfish sea cucumber (Holothuria scabra) in a tidal pool. This is probably the most valuable species of edible sea cucumber in Singapore. The term "edible" is rather deceiving here though. This sea cucumber is actually toxic, and must be properly treated before they can be consumed.


Just before we left the intertidal area, we came across this peanut worm. It quickly burrowed into the sand though.


While heading back to the visitor centre, we stopped by to take a photo of Pulau Sekudu - the Frog Island!

Once again, it was a very enjoyable trip. Hopefully my participants enjoyed it as much as I enjoyed guiding them! :)