Monday, December 21, 2009

Day over at Ubin on 19 Dec 2009

108th Discovery Posting:

On the recent Saturday (19 Dec), I together with a group of nature volunteer friends visited Ubin for a lesson on Birds (thanks to LK for inviting us along) and exploration around the island (thanks to the NParks staff, especially Adelle for hosting us).

It was an early start to the day for all of us as we had planned a morning bird watching session (picture below).
Upon arrival, M pointed out to me this signage found on the jetty on Ubin (picture below). We did had a small laugh over it as there was something wrong about the signage. Can you spot it? I guess there may be a letter printing mistake as it should read: "No Camping Allowed on Jetty".

Anyway, back to the trip. After our bird watching session (no photos as my camera only has a limited optical zoom) in the morning, we set off for our afternoon walk around session. This was nearly canceled as a heavy storm was ongoing on Ubin in the afternoon. Luckily for us, it stopped around 3pm and we went on with our program.

Not long after we set off, M pointed out this (picture below) to us. Can you spot it? Clue: It is green and quite long. Here's a closer look at its head (picture below). First 'discovery' and it is a oriental whip snake.First off, the oriental whip snake is a mildly poisonous snake, although it may not be kill us with its bite, it would still be best not to handle it or any snakes at all. It is commonly found in forested and rural areas and most encountered by us while it suns itself on plants along the forest edge.

For more information and pictures, you may visit: http://www.ecologyasia.com/verts/snakes/oriental_whip-snake.htm

Later in the evening, we were also given a chance to explore the Chek Jawa inter tidal area. It was somehow a highlight for me for the day as I have not stepped on the inter tidal flats of this place for about a year plus ever since helping KS with his project. Here's some photos of the place itself (pictures below)Notice the Chek Jawa boardwalk on the background. Some critters we saw include the second 'discovery', sand stars. Here's one of them (picture below)Some call this (above) the plain sand star. Well, one reason is because there is another kind of sand star. The painted sand star (picture below), third 'discovery'! As you can see, their appearance differs a bit. But you can find long spines along both sides of its arms. Their similarities goes on, they are more commonly seen in our northern shores and are more active when it is dark or near dark. If I am not wrong, they feed differently from the common sea star, which you can find on Chek Jawa as well. For the common sea star, it would push its stomach out from its body to feed while the sand star would usually just ingest or swallow them whole.

Next up, third 'discovery', sand stars (picture below)!They may not look like sea stars, but do you know that they are actually related? Yes, sea stars, sand dollars, sea cucumbers, sea urchins, brittle stars and feather stars all belong to the group of animals which we call enchinoderms. A bit too scientific? Well, then just look closer at the picture above, do you see a star shape? This isn't a good guide to identify animals belonging to this group though.

Anyway, the name sand dollars came about mostly because they resemble dollar coins and at the same time are mostly found in sand bars. They might not alive to you, but if you ever have the chance to handle one, you will feel that they have tiny little spines that can tickle you when you touch them. But do remember not to remove them from sea water for long, as it would stress them.

One more thing which we saw a number was this, a peacock anemone (picture below). Fourth 'discovery'.
They are good to look at and bad to touch. Why? This is because peacock anemones can sting you with stings in their stinging cells. Besides that, do you notice that they have a layers or rings of tentacles? One is the outer, the other is the inner. The function of the outer layer is to gather food from the surroundins towards the inner layer and then the inner layer would transfer food to its mouth. Works like a bit like a conveyor belt, don't you think so?

As we explored, we moved towards the coral rubble area. But alas, the tide wasn't low even for us to even step into the place. So for safety reasons, we decided to just look around the other places in the area. I did however get a nice sunset shot nearby the coral rubble area (picture below). =D As we moved on, we came across this small little biscuit sea star (picture below). Fifth 'discovery'.Like other sea stars, it is best not to take biscuit sea stars off from sea water. But if you do, do return them back after a quick look, as they need sea water as we need blood. This is basically because they circulate their bodies with sea water.

Sixth 'discovery' is one sea cucumber which I think that hasn't been properly IDed yet. But at the moment, I think we are calling it the smooth sea cucumber (picture below).The last featured animal and seventh 'discovery' is a noble volute (picture below).These creatures are probably one of the largest sea snails you can encounter on our shores. This is because noble volutes can grow up to about 10 plus cm long. However, they are threaten as they are collected for their beautiful shells as well for food.

Well, that about wraps up this post. Thanks again to LK for organising and Adelle for hosting us and of course all friends who make it another great day out. =D

Sunday, December 6, 2009

1st time encounter with this Star on Semakau

107th Discovery Posting

Probably one reason that I continue to enjoy going for inter-tidal walks is the joy of discovering something which I have never seen before. And this happened recently on Friday night when we (a few Project Semakau volunteers and myself) went for an exploration walk at Semakau after we did some bird and insect surveys.

In the beginning, I thought that this was a biscuit or cake sea star (photos below).
But after R pointed out that this could be a galloping sand star (Stellaster equestris), I decided to give it a double check. To my joy, R was correct. According to David's Lane, A Guide to Sea Stars and Other Echinoderms to Singapore, the galloping sand star has "variable amounts of dark-pigmented patterning on the oral surface." This was observed on the oral side of the sea star we've seen (photo above). So this is a 'first' for me! Rightfully, the first 'discovery' of this posting.

Not only did we manage to see one of them, but two! Here's the second one (photo below).
I almost forgot to mention that this could be the first time anyone in Singapore has seen it in the inter-tidal area as previous specimens has been only found through dredging. Thanks to R for pointing this out! Oh, by the way, unlike most other sea stars which move by gliding across the substrate, this sea star is able to move by jerking or leaping.

During our walk, we also managed to spot the usual big sea star suspects, the knobbly sea stars. Here's two of them and the second 'discovery' (photos below).Initially, I thought the third 'discovery' was a gong-gong. But R pointed out this was a Strombus marginatus, thanks again! (photo below)I did a quick search and found a recent paper on this shell, here's the link (you can check out the pictures if you're not interested in reading it): http://rmbr.nus.edu.sg/nis/bulletin2009/2009nis379-384.pdf.

It was quite a fruitful night as we across came across a number of squids, here are some photos of them below.It has been said that squids are probably the fastest moving aquatic invertebrates with some reaching up to 40km/h but the ones we saw were quite still. Maybe it was because it was night time or rest time?

Some people like me tend to mix up squids and cuttlefishes, so one good way to tell them apart is to look out for fin. An all round fin is a cuttlefish while the squid's fin is a triangular flap at the tip of the body which acts as stabilisers.

To read more about them, you can go to http://www.wildsingapore.com/wildfacts/mollusca/cephalopoda/squid.htm.

Well, it was a great night out and we were out again on the shores on the night after (sat). You can read about them @
a) http://tidechaser.blogspot.com/2009/12/last-project-semakau-survey-of-year.html
b) http://mantamola.blogspot.com/2009/12/night-trip-to-semakau.html