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!