Hit & Run at Chek Jawa

A fish hit me!

Was pretty sure I wasn’t bitten or stung now that I think back, it just felt like something hit me.

Yesterday, I was back at Chek Jawa with Dr Dan, his colleague and students from Duke University, and Team Seagrass. The photo below was taken after I’ve given our visitors from Duke University a short introduction to the Rhizophora mangrove tree behind, probably a Bakau Minyak (Rhizophora apiculata) since it had red stipules.



As we were crossing a lagoon among the sandflats, I suddenly felt something heavy hit me some where just above my right ankle.

"What the fish!" I exclaimed.

But the water was a little murky with so many of us crossing the lagoon, and the fish was too fast for us to identify it. We could only vaguely see a longish shape disappearing with the waves.

Lifting up my leg, I saw that the fish had taken some of my skin with it.



Like what Alvin said, it’s a case of "hit and run" – I didn’t even know what hit me, species, genus, whatever.

But despite this little incident, and the fact that many of the wild things that we used to see at Chek Jawa were gone due to the flood, we still had a very enjoyable trip.



It was a bright and sunny day at Pulau Ubin - a lovely day to get away from the concrete forest on mainland Singapore. The construction of the boardwalk was proceeding well, and we had to play a bit of hide-and-seek to get to the shore.



We saw quite a number of interesting wild things, including lots of fiddler crabs, hermit crabs, swimming crabs, sand dollars, clams, snails, fishes etc. This mudskipper was found hiding among some rocks.



It’s not as big as a giant mudskipper, but it’s probably the biggest mudskipper I’ve seen so far on Chek Jawa, about 15-17cm long, and it has little blue spots on its body. Looks like a blue-spotted mudskipper (Boleophthalmus boddarti) which feeds on algae and detritus. This is the first time I’m seeing this though, so not quite sure if I’ve gotten the ID correct.

We saw many drills (Thais sp.) and lots of egg capsules as well.



Drills normally feed on barnacles and other shells by secreting an acid to soften the victim’s shell before boring a hole through it with its radula (something like a tongue). Their egg capsules turn purple when the eggs hatch.



Several huge jellyfishes were stranded on the sand bar. The one above was still alive when we found it. Jellyfishes are Cnidarians like corals and sea anemones which have stinging cells. Don't handle them with your bare hands, or you may get nasty stings!



The mantis shrimp (Order Stomatopoda) above was found scurrying among the seagrasses. Mantis shrimps have pincers with sharp spines to impale their preys, such as small fishes.

We were all very happy to find three living sea cucumbers, and among them a ball sea cucumber! Just imagine a month ago, we had dead ball sea cucumbers every where! Seeing a living one is surely a good indication that they are coming back!



The translucent sea cucumber above is probably a Paracaudina australis. It's supposed to have 5 pairs of longitudinal internal muscles. You can see one of the pairs in the photo.



We had thought that this was a sea cucumber or a peanut worm. But Ria later found out it is probably a spoonworm. This was the first time I saw it actually. Read more about it at the Team Seagrass blog.



And not only we found several sea pens (Order Pennatulacea), the one above actually had two sea pen porcelain crabs (Porcellanella sp.) among the polyps! Can you spot them? A sea pen is actually a colony of animals, with a primary polyp (one animal) as the central stalk, and secondary polyps (other animals) making up the feathery end.

But the highlights of the day were these…



The hairy balls you see above are no balls, but are in fact slugs called hairy sea hares (Bursatella leachii)! There were like hundreds or maybe even thousands of them! From what I understand, hairy sea hares normally feed on cyanobacteria. Could this be an indication that the water has lots of nutrients, possibly due to the recent flooding, and resulted in a cyanobacteria bloom?

On our way back to the vans, we saw a cute little crab spider, waiting for butterflies to stop by for lunch.



Indeed, today I’ve again seen a few new things that I’ve not seen before. That just shows our wild shores still have a lot to offer! So those of you out there who have not visited our wild shares, what are you waiting for? Sign up for the guided walks organised by the various volunteer group now! More information can be found at the WildSingapore Website :)

And thanks to the staff and students from Duke University for making this trip so enjoyable. I've learnt many things from all of you, and do look forward to seeing old and new faces again next year!