Sunday, March 15, 2009

Semakau, in the Early Morning Light 140309

A couple of days back marked the last of afternoon and evening low tide windows. So, from now till several months along, trips are scheduled for the early morning.

In the wee hours of Saturday morning, dozens of Project Semakau volunteers left their homes in order to reach Marina South Pier by 5 am. We were going to the island to conduct the first transect survey.

It was still dark when we got to the pier and similarly when the ferry reached Semakau.

As transport is not provided at such an early hour, we had to walk to the intertidal zone from the visitor centre. The early morning air was cool and punctuated with bird calls, as our diurnal feathered friends slowly awoke from their slumber.

In no time, we had walked through the secondary forest and reached the intertidal area. At the beginning of the seagrass meadow, we had an encounter with... unknown sea hare (Order Anaspidea).

Wen Qing, Samuel and myself were in seagrass transect team 2. While doing the survey, we saw plenty of seagrass in the 30 m stretch (but not as much as before like during the transect training) and also some interesting things like the mucus coating made possibly by a wrasse (Family Labridae) or some other kind of fish [edit]. One interesting fact about wrasses is that they can change their gender! O.O

Seagrass is indeed tricky as we soon realised for ourselves...

1) Thalassia hemprichii.

According to the ID sheet, the leaves have "short, black bars of tannin cells". But as you can see, these bars aren't obvious at all. This is a good example of how things in the field often differ from what is on paper... So how to ID Thalassia? Though their sickle-shaped leaves are a good giveaway, if unsure, it's best to feel for their rhizomes which are scarred and appear reddish-brown :)

2) Cymodocea serrulata.

Often confused with Enhalus acoroides and Thalassia hemprichii, this species does have one visible distinguishing feature - a serrated leaf edge! If that does not help, feel for the rhizomes, which are smooth and closer to the surface than Thalassia.

3) Halodule uninervis.

We didn't think we'd encounter this species, so we had to confirm its ID with Ron. The above is a young specimen. It has a white rhizome with black scars. In mature specimens, a distinctive centre vein is visible, and leaf tips have three distinct points.

Mostly, there was a lot of Tape Seagrass (Enhalus acoroides), noticeable numbers of Syringodium isoetifolium (Noodle Seagrass), some Cymodocea serrulata (Serrated Ribbon Seagrass), a little of Halophila ovalis/minor (Spoon Seagrass), even less of Thalassia hemprichii (Sickle Seagrass) and only one quadrat with Halodule uninervis (Needle Seagrass). For more info, visit the I.D. Seagrass page of the Seagrass-Watch website :)

After completing the transect survey, we were given some time to explore. One group followed Ron, while the other followed July. Saw this Sandfish Sea Cucumber (Holothuria scabra) soon after heading out.

There were numerous juvenile Knobbly Sea Stars (Protoreaster nodosus) out that day! Yay! They really come in a myriad of colours. As echinoderms have a water vascular system, they will get stressed and die if left out of water for too long. That's why we always replace them after a quick photo.

Knobbly no. 1.

Underside of Knobbly no. 1

Knobbly no. 2. One of its arms is slightly shorter than the rest which could be a result of an injury and subsequent regeneration.

Knobbly no. 3.

Underside of Knobbly no. 3, with focus on its mouth (centre) and the ambulacaral areas which house its tube feet.

Knobblies no. 4 and 5. The Knobbly on the left looks really 'juvenile' (but that's just my opinion).

Knobbly no. 6. With two of its arms closer than normal to each other, this sea star here looks like it's getting ready to dance.

Saw a few more Knobblies, but didn't upload all the pics here.

Growing in bunches were some green algae (Caulerpa sp.).

This is a first for me! In one of the tidal pools, this Heart Cockle (Corculum cardissa) was clearly visible in the shallow and clear water. When it dies, the heart breaks...

An Orange-edged Black Flatworm (probably Pseudobiceros uniarborensis). Another 'first' for me on Semakau.

Looking like a protrusion from the substrate was this Common Hairy Crab (Pilumnus vespertilio). The hairs on its body trap sediment which, over time, allows it to look like a piece of the substrate itself.

A view of the coral rubble area.

Growing in between this magnificent Staghorn Acropora Coral (Acropora sp.) was a fan shell (Family Pinnidae).

Hmm..egg cases of a mollusc? It's likely an egg ribbon of a nudibranch or some other species of slug.*

This sea cucumber (Actinopyga sp.) is thought to be a juvenile Stonefish Sea Cucumber due to similar physical traits, but that is based on speculation and not yet confirmed*.

This is by far the smallest Noble Volute (Cymbiola nobilis) that I have seen. Is it a juvenile? From its shell alone, I wouldn't have been able to ID it as the typically associated 'mountain ranges' pattern is absent. Lucky its black with orange spots muscular foot was showing.

Saw a lot of these Common Sea Stars aka Sand-sifting Sea Star (Archaster typicus). Here is a pair getting ready to mate with the male on top (such pairing behaviour is known as pseudocopulation) [edit]. Like other sea stars, external fertilisation takes place (meaning reproductive organs don't actually meet).

Wild Fact Sheets of marine life on Singapore shores -

[edit], *Thanks to Ron for the corrections and IDs!

Tuesday, March 10, 2009

The Sun Blazes Down on Semakau 080309

Remember how in primary school there were a couple of 'standard' phrases used in writing compositions? I've never been a fan of them but if there ever was a time to use one, it would be to describe the weather on Sunday. So here goes:

The sun beat mercilessly down on us...(haha!). After doing battle with the mozzies (they love me but the feeling isn't mutual) in the forest trail, we finally arrived at the intertidal area. Split into 2 groups, Wen Qing, Nonis, Xiu Li and myself followed Luan Keng while Hui Yi, Ying Wei and Elvin had Ron as their leader. We were there to pile in the transect markers for the upcoming transect this Saturday. As we headed out...

...LK spotted this Mangrove Horseshoe Crab (Carcinoscorpius rotundicauda). Two species can be found in Singapore - the one above as well as the Coastal Horseshoe Crab (Tachypleus gigas). Two easy indicators to look out for are colour and tail structure. The mangrove species is brownish with a rounded tail while its coastal relative is greyish with spines on its tail. Read more about horseshoe crabs in general here, and the 2 species that can be found in Singapore here.

Kinda seemed apt that the first animal spotted was a horseshoe crab, for on that very day in the evening, a Horseshoe Crab Population & Distribution Survey was conducted around the mainland, organised by the Nature Society (Singapore). I sure hope that minimal damage was incurred for volunteers had to dig up (a lot of) mud in order to locate the horseshoe crabs...

After crossing the seagrass meadow, we entered the coral rubble/coral reef area where two huge pore corals (Porites sp.)* caught our attention with their different colouration.

Sadly, the top of both corals are dead and the scorching sun didn't help matters.

After piling in the transect markers, we had some time to explore. Hunter-seekers who arrived before everyone else found this synaptid sea cucumber (Family Synaptidae) and marked out its location.

Another find by the hunter-seekers was this Noble Volute (Cymbiola nobilis) and its eggs. Was amazed to see that the mass of eggs it laid was as big as it was. Its shell kind of looked faded to me, compared to the previous ones I'd seen at Changi before. Also, it was smaller. Size can't be used to judge its maturity, I realised.

A dead octopus (Class Cephalopoda, Order Octopoda).* Wen Qing's close examination of it revealed that some of its tentacles were shorter than the others. We learned from one of the visitors that tentacles can get bitten off by predators and are subsequently regenerated. Cool!

Bakaus (Rhizophora spp.) greet visitors to the Semakau intertidal area. Learned that 2 species can be found growing on the edges of the sandy shore - R. apiculata and R. stylosa.

Though both species look similar, they can be told apart even at a distance by their roots. Both mangroves have stilt or prop roots, but those of R. apiculata are not so spread out as compared to that of R. stylosa. In addition, the stipule^ of the former is red while that of the latter is yellow. The stipule wraps over the apical bud, protecting it. The red stipules will eventually drop off as the young leaves grow.* Can you tell which picture is of which species? One last thing to note, R. apiculata has a shorter flower stalk than R. stylosa.

Another Rhizophora species, R. mucronata has big leaves which distinguish it from the two above.

Taking one last look at a Rhizophora stylosa before we leave.

Some other things seen but not photographed:
i. Mosaic Crab (not too ducked for cover really quickly so I only caught a glimpse)
ii. Crab with yellowish-brown carapace (ditto the above)
iii. Black-lipped Conch
iv. Sand-sifting Sea Star aka Common Sea Star
v. Ovum Cowrie
vi. Eagle

Heard about the sightings of Knobbly Sea Stars and turtles from Ron but didn't get to see them D:

Thanks to LK for the info! And to everyone for the company :)
*Ron, thanks for the corrections!
^Thanks to Anonymous for bringing my attention to the terms used (ie. stipule and apical bud)! [Refer to Anonymous' comment]

Given the weather, a cap and a lot of water are essentials!

For other takes on the trip, check these entries out:

Reality Check.

I feel heartened every time I read or hear about people doing their bit for nature. It's great that ordinary folk spend time educating the public and channelling their energies into conservation work. Then there are those who don't care and these people really get my goat.

After Pedal Ubin, we were in high spirits as we headed toward the jetty to take a bumboat back to the mainland. As it was low tide, the mudflats were exposed and we spent some time looking down for signs of life from our position on the walkway. Walking slightly ahead, I suddenly stopped short at the sight of people crouching down on the mudflats. Okay, no reason to get alarmed yet. When I got closer, the sight that lay before my eyes (and for anyone who bothered to look) confirmed my earlier suspicion.

A group of five (a mix of both males and females), with at least one wielding a long stick and a plastic bag, were nonchalantly trampling on the mudflats and destroying the burrows made by the crabs. Destroying the mudflats by trampling? Hardly. With their long stick, they proceeded to insert the end into burrow after burrow. As they pulled the stick back up each time, a lot of mud was dislodged intentionally. Disgruntled that no crabs were getting caught, they repeated the process again. One of them even took out his camera to take his friends in action.

The above happened in a matter of seconds, and by that time, the others (some guides and participants who were heading back to Changi Village) had gathered and they started calling verbal deterrents to the group below. Mindy and I informed the NParks guy at the information kiosk, who grudgingly roused himself from his nap to entertain us. As we told him what we saw, he pointed to the map of Pulau Ubin laid out and said that only Chek Jawa is a restricted we (meaning NParks) have no power..can only stop them if they're damaging or killing things (I specifically remember him giving seahorses as an example). In short, he made it sound as if people are free to do what they like in the areas that are not protected.

Clearly those people were causing damage!

We finally got him to follow us after some time (didn't seem willing to leave his post), but by then, we only saw the backs of the intrepid hunters who had finally decided to leave.

Okay, so NParks has no power to stop people from damaging areas that are not protected. Seems reasonable enough, for not ALL areas can be protected. What if endangered animals happen to live on shores/in areas that have no protection? Can poachers poach all they want?

Where do we draw the line?

The NParks staff have the option of telling people to cease their detrimental activities, but otherwise, nothing else can be done. I just called the NParks management office to ask for their take on this matter. Much of what was told to me I already heard from his fellow colleague, except that he put it across in a much nicer way. Something new to me was that the area in question falls under the jurisdiction of the LTA and even HSBC.

I asked the guy what NParks is doing about areas with no protection. His answer was that they are trying to get something done but there are politics involved. Not that word again, please.

What can we do to help?

The matter with red-tape aside, I can see why education is imperative in spreading the message of conservation. Ignorance can be attributed to the harm humans inflict and this can be reduced through education. Don't wait around for authorities to implement some policy or kick off some campaign to 'save the Earth'. It can start on the individual level, if you let it.

Did you ever collect sea shells when you were a kid? For many people, myself included, I thought that it was a harmless activity. On the day that I found out shell collection had negative effects (depriving hermit crabs of their homes, etc), I opened my mouth to start a reply but closed it when I realised that all I had to say started with either "I didn't know" or "I didn't think".

Saturday, March 7, 2009

Pedal Ubin! 070309

Moments after we set foot onto Pulau Ubin, a steady drizzle started which threatened to dampen our mood. Luckily, the rain abated quickly and we soon embarked on our first Pedal Ubin experience :D

Dark clouds were starting to obscure the sun...(played with my photo-editing programme).

Saw quite a lot of these birds wheeling overhead. They are Pacific Swallows (Hirundo tahitica) and are resident birds.* I've not been able to get a close look at them yet...

Before the Toddycats! guides brought us out, we were asked to test out our bikes (by playing with the gears, etc). Each group had around 13 participants and set off in intervals.

While waiting outside the Pulau Ubin Volunteer Hub, I turned my attention to the occasional bird in the vicinity. Blurry pic (argh!) of what looks like a Yellow-vented Bulbul (Pycnonotus goiaivier).

In no time, we were off and peddling hard to get to our destination (the destination of each Pedal Ubin trip varies) - Chek Jawa (CJ)! Upon reaching the CJ gates, we dismounted and parked our bikes in the bicycle stands provided, proceeding to advance on foot.

On our way in, we saw a couple of these mushrooms. If conditions are moist and humid, expect fungi! Based on their morphology, these mushrooms here are probably basidiomycetes (mushroom or club fungi). (ID?)

While exploring round the back of House No. 1 (CJ's visitor centre), Ze Lin spotted this pair of mating bugs. Are those droppings as pointed out by Samson Tan? (ID?)

ZL (with his sharp eyes) alerted us to this very well-camouflaged caterpillar. It was huge: around 8 cm long and 2 fingers wide o.O I remember there being comments like, "What kind of butterfly will it turn into?". I'm wondering too!

Identity revealed by Ron. It's the caterpillar of an Atlas Moth (Attacus atlas).* The moth is indeed big, with a wingspan of around 25 to 30 cm. Wow!

Just a stone's throw away was this much smaller white caterpillar with 'spikes'. (ID?)

At the front of House No. 1, there is a huge tank which houses marine animals that need rehabilitation. Currently, the tank is not in use as it's undergoing 'upgrading'. However, many terrestial bugs have fallen in and subsequently died, like this Scarab Beetle (Family Scarabaeidae).*

If memory serves me, those leaf-like 'pouches' are actually the modified petals enclosing the seed. Wrong info!

Those aren't modified petals, but modified leaves called bracts and belong to Flemingia strobilifera.* According to, a bract is a modified leaf growing just below a flower or flower stalk. Bracts are generally small and inconspicuous, but some are showy and petallike, as the brightly colored bracts of bougainvillaea or the white or pink bracts of flowering dogwoods.

I believe this is a weaver ants' nest.. (ID?)

The view from the top of the Jejawi Tower in Chek Jawa.

As we were making our way down from the tower, this bird caught my eye. (ID?)

Curious indeed! This spider web was strung near the supporting pillars on the tower (forgot which storey). What are those lumps? Hmm..bundled up prey?

Mindy noticed the spider eating one of the lumps! (ID?)

Mud Lobster mounds can be found on both sides of the Chek Jawa Boardwalk. Though the mounds are common, the Mud Lobsters (Thalassina anomala) themselves hardly ever make an appearance.

The Nipah Palm (Nypa fruticans) is the only true mangrove palm. Its immature fruits are used extensively in desserts like Ice Kacang, and are commonly known to us as attap chee. Apart from satisfying one's sweet tooth for attap chee, this plant is commercially important as its parts - such as the fronds and sap - are used widely.

Mindy spotted this strange-looking spider. Got a clue from Samson Tan about its identity. Following it, I think this spider may be a Big-bellied Tylorida (Tylorida ventralis), a species which is falls under the Big-jawed Spiders family of Tetragnathidae.

The inflorescence of a Nipah Palm.*

The shape of their web give tent spiders (Cyrtophora spp.) their name.

Pausing for a rest on a Mud Lobster mound was this Dusky-gilled Mudskipper (Periophthalmus novemradiatus).

For more info about mudskippers in general (Family Gobiidae), check out

Scuttling about were the tree-climbing crabs (Episesarma spp.). One of the our guides, Tina, I think, mentioned how it's weird that she doesn't ever see the crabs climb the trees at CJ though they can be caught in action at Pasir Ris/Sungei Buloh.

Ron says: "You will see the tree-climbing crabs climbing trees when it's high tide. The crabs climb trees to escape from predatory fishes.".

A couple of leaves of the Sea Hibiscus (Hibiscus tiliaceus) were covered with a moving mass of Cotton Stainer Bug (Dysdercus decussatus). They are said to group together for the purpose of finding mates.

As we continued walking along the boardwalk, ZL gestured for Wanwei and I to come over. Our approach caused this crab to take cover, but luckily it emerged a few seconds later.

Later on, at NUS, I showed Ron the pic and found out more about them. Prof Peter Ng said that they look like Uca triangularis (Uca is the name of the fiddler crab genus) while Ron and LK provided the following info: the burrows (seen above with a crab guarding it) are known as chimneys and are built by the females. As female fiddler crabs do not have an enlarged pincer like the males, they are able to eat twice as fast. With meal times ending quickly, females have more time to build the chimneys which they use to protect themselves (no enlarged claw to fight with).

The chimney-building habit is specific to a few Uca species only. Uca triangularis and Uca paradussumieri juveniles are two such examples.*

Initally, I thought that the two Uca triangularis I caught on camera were females...but upon closer inspection, doesn't the right claw of the crab in the photo above look rather odd? Could it be a male?

This one here, though, is definitely a female.

This looks like the Blue-spotted Mudskipper (Boleophthalmus boddarti).

Looking like a mini ice cream cone was this Creeper Telescope Shell (Telescopium telescopium) lying on the mudflats.

This bug (spotted by Mindy) looks as if it has a smiley face painted on its abdomen :) (ID?)

Saw Mindy squatting by the side of the boardwalk and found out later that she was looking at this mudskipper here! It has red pelvic fins, something which I've never seen before. (ID?)

Is this an ant? Nope! It's a juvenile praying mantis (no evidence of wings). 2 pairs of its legs are on the leaf while its forelegs are held just below the head.* In some species, the nymphs rely on ant mimicry to aid them in their survival. Well, it certainly fooled me!

3 Cotton Stainer Bugs and 1..?!? (ID?)

The underside of a female Golden Orb Web Spider (Nephila maculata).
The species name has been updated to pilipes.*

The tide going out (~0.6 m), and exposing the mudflats...where many male fiddler crabs (Uca spp.) were out.

A closer look at them.

This Common Tailorbird (Orthotomus sutorius) would perch on a branch, twitter a few notes of a song, and then quickly dart to another tree. It hardly kept still!

A second after I took this pic, this Greenish Grass-dart (Ocybadistes walkeri) took off. Thought it was a moth but it's actually a Skipper butterfly like Ron said.

How do you tell a butterfly and a moth apart? For one, butterflies have club-shaped antennae. Find out more info about these creatures here and here.

As Pedal Ubin was coming to an end, we departed from CJ and cycled back to the volunteer hub. On the way back, there was still lots to see!

Can you see me? Twined loosely around a branch of similar colour was this snake. (ID?)

We made a stop at the headman's house where this Blue Glassy Tiger (Ideopsis vulgaris macrina) was flitting about in the garden of sorts.

Translucent wings.

Juvenile rambutan fruits? Far from it, as I just found out from Ron. These are the fruits of the White Mulberry (Morus alba).*

The best description I can think of is 'bright pink furry flower'! This is Cockscomb (Celosia Cristata).*

The young blooms of the same flower.

Pedal Ubin was an enjoyable experience and I do hope to participate in it again! The next one is coming up in June :)

Credits to Mindy for the pics of the two unknown spiders, insect with smiley face on its abdomen and mudskipper with red pelvic fins.

*Thanks to Ron for the IDs and info!

I've been using the terms 'insects' and 'bug' interchangeably but there is a difference! Thanks to Mindy for pointing it out!

Got this off Wen Qing's blog: "True bugs belong to the Order Hemiptera (hemi = half + ptera = wing) because of its forewings which are hardened near the base, but membranous at the ends. Its defining feature is its possession of mouthparts which have evolved into a proboscis and forms a "beak" of sorts which is capable of piercing tissues (usually plant tissues) and sucking out the liquids, usually sap.". So..there are bugs, and then there are insects :)