Fallen Star - by no fault of its own 260809

… kidnapped from the sea and laid to rest in a grave of chlorinated water.

I was taking a stroll around Toa Payoh Sensory Park when something highly irregular caught my attention. In the middle of a water feature, partially submerged, lay a dead Knobbly Sea Star (Protoreaster nodosus). Yes, a knobbly. Looking at it, it had been preserved and dried; the colour all bleached out of it.


Some pet shops (not limited to, I think, that specific one in the town area) do sell ‘exotic’ creatures like Knobblies, among other, ‘pets’. They may live for a little while in captivity, but I daresay that most do not survive. A while back, I read about there being sales of these stars - preserved - in some shops, apparently as a curio (thanks Ria, for trying to help me find the article); their value indicated by a price tag.

Does that sound right to you?


Knobblies are listed as 'threatened', their numbers having taken a plunge due to over-collection for the live aquarium trade, among other things. Like everything else, the best way to halt supply is to curb demand...

Birds in the Neighbourhood

Crows? Oh, definitely. Mynas? You bet. Ah! Sparrows too.

Most, if not all of us, have definitely seen or heard these birds; their calls punctuating the rhythm of our daily lives. While walking to school, it’s a one hundred percent guarantee that I surely will encounter Rock Pigeons (Columba livia). Whether perched on top of a lamp post or gathered in flocks (sometimes in the middle of a walkway when food has been thrown out), upon seeing them, my brain inadvertently screams ‘Avoid, avoid!’ for fear that I will be on the receiving end of their dive-bombing activity (read: pooping).

Birds, well, are birds, and they are just doing what they do best – being birds – albeit in the city. I have lived in the same neighbourhood for close to two decades, and until recently, my knowledge of birds was limited to crows, mynas, sparrows, pigeon and that unknown yellow bird (Black-naped Oriole). Airborne birds were relegated to the category of ‘those little black splotches flying high above’. It’s amazing to find that there are so many different kinds of birds living alongside us, after all. Most are shy and prefer to maintain their distance from people, so they may be heard (eg. Collared Kingfishers, Asian Koels, Gerygones), but not often seen unless one seeks them out. Of course, there are also chance encounters with our feathered friends…

…I was rushing for time; the bus was on its way. As I rounded a corner, something darted into the foliage of a Chiku tree (Manilkara zapota) with a lot of rustling. My curiosity got the better of me and I just had to look. To my utter surprise, I saw a *female Pink-necked Green Pigeon (Treron vernans) perched on a branch and eating the fruit. Wow! I was about a metre away and thus had a really good look. I’ve frequently encountered them in Kent Ridge but that was my very first time seeing it in my neighbourhood (after nearly twenty years…sigh). While fervently hoping that it wouldn’t fly away so quickly, I hurriedly got out my camera and managed to catch a few shots.

Perched on a branch, blending in almost perfectly with the leaves (indeed, I got a few weird looks from passers-by), the bird rapidly tucked into its meal. It would scoop up the soft flesh with its beak, going almost vertically to do so (as in the picture), and then right itself, throwing back its head slightly to swallow the bit of fruit.

The PNGP with the bit of fruit in its beak :)

Swallowed.

Down it went again...

The pigeon continued to feed in such a manner for quite some time. It was a delight to watch :) though I can only hope that I wasn't disturbing its meal (the encounter occurred at around 4 pm...so I guess you can say that it was tea-time?). Too bad I didn't get a shot of the bitten fruit... I did walk around the tree to look at it though and saw that a quarter or more of it had been eaten. (In case you were wondering, I did catch the bus in the end but had to do a mad dash for it. Hehe.)

So what else can one spot in the neighbourhood? A short stroll around a park in the evening recently led to sightings of a Yellow-vented Bulbul (Picnonotus goiavier) and a tailorbird (probably a Common Tailorbird - Orthotomus sutorius). Check out gopalarathnam_v's photostream on flickr, as well as Ingo Waschkies gallery on PBase for amazing shots of the Common Tailorbird.

Here's a list of the birds that one can commonly see/hear in urbanised areas in Singapore:
1. House Crow (Corvus splendens) - not to be confused with the Large-billed Crow (C. macrorhynchus) which is native to Singapore
2. Javan Myna, also known as the White-vented Myna (Acridotheres javanicus) - another introduced species
3. Common Myna (A. tristis) - these are less abundant than their introduced counterparts, having faced competition for resources from them. These mynas have a reddish-brown body, unlike the largely black plumage of their relatives
4. Eurasian Tree Sparrow (Passer montanus)
5. Rock Pigeon, also known as the Feral Pigeon (Columba livia)
6. Black-naped Oriole (Oriolus chinensis) - I always think of the song that goes "...yel-low bird, high up in the ba-na-na tree..." when I see them
7. Collared Kingfisher (Todirhamphus chloris) - look out for a streak of blue whizzing by!
8. Asian Koel (Eudynamys scolopacea)
9. Golden-bellied Gerygone (Gerygone sulphurea) - thanks LK for the ID! For many years I have listened to its wheezing call and never knew its source. See Paul Huang's photos of this shy bird.
10. Oriental Magpie Robin (Copsychus saularis)

Birds in the photos above (from top to bottom): Javan Myna, Little Tern (Sterna albifrons) and Pink-necked Green Pigeon.

*Unlike their more commonly sighted counterparts, the Rock Pigeons, which feed on a wide range of food, Pink-necked Green Pigeons are frugivores. They also exhibit dimorphism, with different colouration between the sexes. Males are more colourful than females. Most noticeable would be their pink-purple neck and upper breast, as well as an orange lower breast. Females, as shown in the pictures, mainly have green plumage.

10 Fruit Trees of Pulau Ubin 200609

Some RMBR volunteers met up on Saturday morning for an outing to Pulau Ubin cum durian feast. More about that in a later blog post! In this entry, ten fruit trees of Pulau Ubin which we saw will be featured. In horticultural usage, 'fruit tree' refers to a tree whose fruit is used for human consumption. So even though all flowering plants bear fruit, not all are called fruit trees. And 'trees' can be a misleading term...

The first fruit tree that we saw, which, at this time of year, is terribly hard to NOT notice was the Rambutan (Nephelium lappaceum). When I was a kid, I used to be unable to tell the difference between Lychee (Litchi chinensis), Longan (more than one species) and Rambutan. Well, there're all from the same family of Sapindaceae! Even now, I keep thinking that Lychee is Rambutan..and Longan is Lychee..you get the idea. Perhaps the following associations will help:

Rambutan - red and hairy (rambutan, derived from the Malay word rambut which means hairs)

Lychee - red and NOT hairy

Longan - brownish-yellow and NOT hairy

Rambutan trees grow in countries with tropical climates. They are evergreen ie. having leaves all year round. Some trees are dioecious while other are hermaphroditic.

The second fruit tree that we came across was that of the Custard Apple (Annona squamosa) (note: the common name refers to all three species in the genus Annona). This variety hails from the family Annonaceae which grows well in warm, humid climates. According to this website, "[t]here is a thick, cream-white layer of custardlike, somewhat granular, flesh beneath the skin surrounding the concolorous moderately juicy segments, in many of which there is a single, hard, dark-brown or black, glossy seed, oblong, smooth, less than 1/2 in (1.25 cm) long.". I remember eating a custard apple a very, very long time ago and thus cannot remember how it tastes like. Probably was not fond of it which explains why I've not eaten it ever since.

What's a durian feast without durians? In Pulau Ubin, a noticeable number of Durio zibethinus trees grow just along the main trail. When not fruiting, this tree, which hails from the family Malvaceae, can be distinguished by its leaves which have a bronze underside. There are 30 recognised Durio species but the one mentioned here is the variety which is available in international markets.

The durian has long been nicknamed 'the king of fruits'. The ripe fruit has a pungent, distinctive smell and comes in multiple segments. The seeds, found in shallow recesses in each segment, are covered in a soft and custard-like flesh, ranging from cream white to yellow and even red, depending on the species. Apart from the smell, the other distinctive feature is, of course, the husk, which is very prickly. Wallace, a famous naturalist, apparently said that for one to appreciate durian, he or she has to eat it three times. I used to love eating durians back when I was a kid but have since assiduously tried to avoid them (though what possessed me to eat some on Saturday is beyond me...).

Contrary to the title of this blog, the banana (Musa spp.) is not a tree but a herb - the world's largest herb, in fact. Basically, herbs are plants which have non-woody stems. The humble banana (family Musaceae) has its origins in Southeast Asia and over time, with the rapid spread of globalisation, it became well-known to the world. Musa comprises both dessert bananas (what we eat in Singapore) and plantains. The former is eaten raw while the latter has to be cooked or processed in other ways. Plantains have lower water content, making them drier and starchier than fruit bananas. They typically form a staple in the diets of people living in places such as Central America, the Caribbean and Peru.

The picture above shows the main stalks of banana plants which grow from rhizomes underground. In due time (if not already), the terminal inflorescence will grow out from the top of the stalk, and bear fruit. Each stalk produces one huge flower cluster and then dies. New stalks then grow from the rhizome. In summary, the growth of one main stalk is as follows:

Rhizome (produces more than one shoot but most are cut back in order to allow energy to be channelled to fruiting of the main stalk) -> new shoot (typically called a sucker) -> large leaves -> terminal inflorescence -> fruiting (bunch o' bananas) -> main stalk dies -> cycles repeats itself (main stalk forms from a new sucker of the same rhizome)

I was really confused about the whole process of propagation until I chanced upon these sites which can be accessed here and here (good diagram showing the parts of a banana plant). This other website details how the popularity of bananas spread and explains an interesting phenomenon - negative geotropism - which banana plants exhibit.

Hope you aren't suffering from banana overload (like I was). Here are a few more interesting things:

i. fibres are obtained from the stalks which can be made into material (for clothes) and other items such as bags. The pic on the right is a close-up shot of a bag made from banana fibres. It was given out by the Filippino restaurant, 7017 Flavours, on their anniversary. The staff there wear uniforms made from the fibre too.

ii. banana hearts (ie. male banana flowers) are used in dishes like rojak. They look like pink curlicues once cleaned off of gravy.

This pretty pink-streaked flower belongs to the Starfruit (Averrhoa carambola) (family Oxalidaceae).

Here, you can see the developing fruits which still have some way to go before ripening. The common name comes from the appearance of the cross-section of the fruit. It closely resembles a star, with both its (yellow) colour and shape.

Often eating with sour plum powder, the guava (Psidium spp.) (family Myrtaceae) is another fruit that is a favourite with locals. Apart from eating it fresh, guavas are also consumed in their preserved form. Personally, I prefer the preserved ones even though they remind me of curled-up pieces of dead skin (haha!).

When crushed, the leaves of this tree give off, what else, but a guava-ish smell.

I was surprised to see Cacao tree (Theobroma cacao) (family Malvaceae) growing in Pulau Ubin. Didn't think that they grow in this part of the world. Theobroma means 'food of the gods' in Greek, and indeed, processed cacao beans are what gives us cocoa from which the much prized chocolate is made. Each cacao pod contains 20 to 60 seeds (usually called beans). These contain a high percentage of cocoa butter, a fatty substance.

You'd think that with cocoa being so prized and all that everything about the plant must be grand. While flowers of many plants are pollinated by butterflies/moths or bees, cacao flowers are pollinated by...flies. Clearly, flies are not to be looked down upon.

While taking a break from writing this blog entry, I munched on some coconut candy - a sweet confection that is made from grated coconut. Coconut trees (Cocos nucifera) hail from the palm family of Arecaceae (Palmae is now considered taxonomically invalid), and are the only species in the said genus. Nearly everything about them is useful, from the nuts to the leaves.

Coconut palms are often seen growing by the coast for they are dispersed by water. The fruit itself has a hollow cavity that is filled with a liquid commonly called coconut water. The air-filled space allows the fruit to float on the surface of water.

I can't help but think of the Coconut Crabs (Birgus latro) upon the mention of Coconut Palms. These crabs have been observed to crack open coconuts whether by using their chelipeds or climbing up a tree and subsequently dropping the fruit to crack it open. Read more about their behaviour here and here.

This plant here is not a tree, but a climbing vine. The luscious (probably unripe) fruit here is a passion fruit (Passiflora spp.). Not sure if this is the kind that is consumed though. When ripe, the fruit is harvested and the juice, along with the pulp-covered seeds, are used in a variety of ways. In Singapore, it is not uncommon to find bubble tea that is passion fruit-flavoured.

Being a climbing vine, the plant has tendrils which it twines around a support structure. When mature, the evergreen leaves are deeply 3-lobed and finely toothed.

I 'expired' rather quickly that day and left out two other fruits which LK pointed out, namely, the Jackfruit and Nutmeg. After rooting around, I realised that I did have the resources to finish this entry (with a number 11 even), after all :D

Here we go...

Another fruit with a pungent smell is the Jackfruit (Artocarpus heterophyllus). It is the largest tree borne fruit in the world. The leaves are oblong, oval, or elliptic in form, 4 to 6 inches in length, leathery, glossy, and deep green in color. Juvenile leaves are lobed. This tree is commonly planted in and around housing estates. It is closely related to the Cempedak (Artocarpus champeden). Currently, I am not able to differentiate the two... Both hail from the family Moraceae.

Photo taken from nunukphotos.com

I'm not sure which species of nutmeg (family Myristicaceae) the ones found at Pulau Ubin belong to, but if I needed to hazard a guess, it would be Myristica fragrans, which is a commercially viable species.

The seeds are dispersed by big birds (which have bigger beaks and able to swallow larger fruits) like Imperial Pigeons and hornbills. For germination to occur, the seed has to swallowed and passed through the gut of the bird. Only then can the astringent mace (lace-like covering) around the seed be removed. With the dwindling numbers of big birds in Singapore, the nutmeg is suffering.

Nutmeg is used in cooking and baking as a flavouring. The powdered form available in supermarkets is obtained from grating the seeds. The mace is also used. Both impart a similar flavour.

Quite a few of the fruits featured are heaty, such as the Rambutan, Durian, Jackfruit and Cacao. Starfruit is cooling.

To recap, here is a list of the 10 fruits featured:

1. Rambutan (Nephelium lappaceum)
2. Custard Apple (Annona squamosa)
3. Durian (Durio zibethinus)
4. Banana (Musa spp.)
5. Starfruit (Averrhoa carambola)
6. Guava (Psidium spp.)
7. Cacao (Theobroma cacao)
8. Coconut (Cocos nucifera)
9. Passion Fruit (Passiflora spp.)
10. Jackfruit (Artocarpus heterophyllus)
(Additional) 11. Nutmeg (Myristica fragrans)

Braving the Rain at Pasir Ris 140509

Even before the trip started, KS informed us of the impending storm that was blowing over from Sumatra. We could see dark clouds gathering, but decided to start exploring anyway.

Very happy that there were quite a number of 'firsts' for me today again :) Starting them off was this peanut worm (Phylum Sipuncula). They are called peanut worms as their skin, when contracted, resembles the texture of a peanut shell. More on different kinds of worms soon. Haha.

As I walked on, I decided to take a look at one of the many tidal pools. Though there didn't seem to be anything interesting at first glance, movement soon caught my eye. A piece of shell was moving when it had no obvious reason to (there was no water current in the pool). I was pretty sure that a Leaf Porter Crab (Neodorippe callida) was the cause, and yeah, the little crustacean indeed had taken refuge under the shell.

When I flipped the shell over, the Leaf Porter Crab kept really still (playing dead, perhaps?) while lying wrong side up. After several moments, with its legs twitching into action, it righted itself and proceeded to scurry under the shell.

I remember that during the biodiversity practical we had in school, we caught a Leaf Porter Crab - a large specimen it was too! It was carrying a small rock around, a most peculiar sight.

In the same pool, there was a lone Striped Bead Anemone.

Even broken shells are useful! Making this broken shell its home was a small hermit crab.

Further up the shore, I saw many Black Sea Urchins (Temnopleurus toreumaticus). Many were tangled in the seaweed. Tried to rescue a few that were stranded..but there were just too many. Like KS says, we should let nature run its course..

The two pictures at the top show a test - its skeleton - of a Black Sea Urchin. The bottom two pictures are of a live sea urchin. As always, there is a banded worm curled around the mouth of the echinoderm. When flipped over, the beak-like structure of its mouth is visible. It is called the Aristotle's lantern after Aristotle (a famous Greek philosopher) who first described it.

More echinoderms, this time a ball sea cucumber (Phyllophorus sp.). Found it among the seaweed and brought it down into the water. Got a bit of a shock when I turned it over and saw a small crab scuttling over the sea cucumber (pic on the left).

This Mini Carpet Anemone (Stichodactyla tapetum) was the only one that I came across. Wonder if this anemone has any mutualistic relationship with shrimp or nemos. In the picture on the left, a prickly ball sponge can be seen. Both organisms may look harmless, but they should not be handled. Anemones have stinging cells and sponges have spicules which can easily get embedded in one's skin.

Just beside the carpet anemone was a large rock. In one of the recesses of the rock, water had collected. Though the surface of the water was calm, some current was being generated within. Intrigued, I squatted beside the rock for some time and caught the following sequence of pics.

It's a strange feeling when a Thunder Crab (Myomenippe hardwickii), stares at you with one red-lined green eye. It would inch slightly out of the hole, raise its left pincer out of the water and retreat quickly. At one point, it even stuck its eye out of the water. The water was rather murky, but I could see some feathery extensions from its mouth which were waving about in the water as the crab generated a current. What could these extensions be? I would have liked a clearer look, but did not want to disturb the crab (further).

These yellow egg cases are rather commonly seen on rocks along the shore. They belong to a mother Spiral Melongena (Pugilina cochlidium), a mollusc which is encountered rather frequently.

Okay, it's time for the worms! As you can see, I was rather fascinated by these worms. They were writhing about the area just behind the Spiral Melongena eggs.

At first, they appeared to be connected. Note their light blue and black colouration.

Subsequently, they moved apart. Hmm..were they mating?

Here's a close-up shot of one of them...

...and another of the worm on the right. Can't find their ID =X

When while along, I glanced at a patch of seaweed and noticed this small crab with long eye stalks. It's probably a sentinel crab (Macrophthalmus sp.).

This bivalve shell is really pretty with its different band of colurs. Wonder what mollusc it belongs to.

More molluscs! This time gastropods. These are Tiger Moon Snails (Natica tigrina) which secrete sand collars to lay their eggs. As you can see, the two moon snails on the left were engaging in some strange (maybe it is just strange to humans) behaviour. One was enveloping the other with its muscular foot.

Ah! The highlight of the day has to be the two octopuses (Family Octopodidae) which sharp-eyed ZL spotted. This small smooth headed octopus was pulling itself along the spoon seagrass. We later brought it down to the water.

It bunched itself up.

Octopuses are able to change colour and this one did! It was purplish-gray when among the seagrass and changed colour to match its new surroundings.

ZL spotted the second smooth headed octopus as well. It was noticeably bigger than the first. One of its tentacles was shorter than the rest, probably as a result of injury.

This purple sea cucumber (is it a purple under-a-stone sea cucumber?) was firmly stuck to a rock.

Back to worms. Haha. Might this be a bristleworm?

This really small snapping shrimp (note the enlarged pincer) was keeping very still when we chanced upon it.

This prickly sponge had anchored itself to the side of a rock.

At the strand line, a lot of seaweed had washed up along with these blob-like creatures. Can't say for sure what they are, but they might be ascidians. Within them, petaloid patterns were evident.

Ria found this test of a heart urchin (Order Spantangoida) just as we were about to leave. Unlike other sea urchins, heart urchins lack the Aristotle's lantern structure.

For more on today's trip, check out Ria and KS' entries at http://wildshores.blogspot.com/2009/05/prickly-day-on-pasir-ris.html and http://wondercreation.blogspot.com/2009/05/pasir-ris-after-rain.html respectively.


Note to self:
Put spare clothes in a waterproof case next time. As I'm actively cutting down on plastic bag usage, I decided to just stuff my clothes in my bag. Not the best idea coz that set got wet as well. Prolly I should reconsider changing my stance on plastic bag usage to 'use when necessary'.

The Secret Side of Sentosa 130509

All, if not most of us, attribute things like beach volleyball and suntanning sessions to the sunny island of Sentosa. So what's this about Sentosa having a secret side? Well, not so well-known is the existence of marine life that has made the beach-goers haven their home.

Had the chance today to explore an islet off Siloso beach and more. And indeed, they were full of life!

This echinoderm - the rare Laganum Sand Dollar (Laganum depressum) - was the first of the 'firsts' for me today.

Though the water was murky, ZL spotted this baby horseshoe crab drifting in the water. During a previous shore exploration at Pasir Ris, we saw one just like it. Wonder what makes them green!

Sea cockroaches (Ligia sp.) are very common at rocky shores. They can be seen scurrying back and forth, here and there, over rocks. They remind me very much of Plankton in Spongebob Squarepants, but Plankton really is a plankter (singular form of plankton).

The rocks were encrusted with noticeable number of oysters (Family Ostreidae).
Oysters are filter feeders and will open their shells a little during high tide to sieve food particles from the water.

Attached to the side of a rock was this flowery soft coral (Family Nephtheidae). Both hard and soft corals belong to the same phylum of Cnidaria, but differ most significantly in that the former builds calcium carbonate skeletons while the latter do not.

The shores are colourful! Ascidians, such as the ones above, come in a variety of colours and can be colonial or solitary. The two pink blobs above are separate colonies of ascidians.

This Spotted Moon Crab (Ashtoret lunaris) was the second crab I saw on the islet. Its legs are paddle-shaped, which allows it to burrow very quickly into the sand.

Bet you're wondering what happened to the first crab... While exploring the rocky area, I heard a scrabbling sound, turned to look, and saw that a brownish crab had fallen from higher up and landed on one of the lower rocks. More scrabbling later, and it disappeared from view.

These Common Sea Stars (Archaster typicus) appeared on the sandy shore, seemingly out of the blue. Quite amazing, really. We had no idea that they were there, hiding in the sand, till they decided to make an appearance. Two of the sea stars have paired, getting ready to pseudocopulate (meaning that their reproductive organs do not actually touch). They can remain paired for up to a few months, before sperm and eggs are released into the water.

Third encounter with a crab. I have no idea what species it is. Found it lying wrong-side up in the sand and flipped it over. Its pincers have a reddish tip.

This prawn apparently jumped out of a hole near the Common Sea Stars.

Though the terms 'prawn' and 'shrimp' are largely used interchangeably, there is a difference! Prawns and shrimps may look alike, but upon closer inspection, the difference can be elicited by the arrangement of the second abdominal segment. For prawns, each of their abdominal segments (and thus the second abdominal segment) is overlapped by the preceding one. In shrimps, the second abdominal segment overlaps both the preceding and following ones. Read more about their differences here.

Soon, we left the islet and made our way to Tanjong Rimau to continue exploring :)
The beach which we cut across had a lot of 'wrinkles' which never ceases to grab my attention.

This fan shell (Family Pinnidae) was lying on the beach, in full view. As these molluscs typically burrow into the sand and anchor themselves to the substrate by strong byssus threads, it was really weird to see one lying out in the open. The valves were slighly open, and we could see the soft body of the animal. Can't tell if it was dead or alive. My guess is that someone or something dug it up.

In one of the modules that I took this semester, we learned a bit about the caves and cliffs (I was so surprised when I learned that Singapore actually has cliffs!) found at Tanjong Rimau. It's one thing to learn from textbooks, and another to actually see it for yourself! As you can tell, I was rather excited to be there :)

For the module (The Biophysical Environment of Singapore), we used a textbook entitled Singapore's Biophysical Environment by Lu Xi Xi, Wong Poh Poh and Chou Loke Ming. Here's an extract from it pertaining to Tanjong Rimau:

"Two major types of cliffs are left in Singapore. Sedimentary rock cliffs are located on the northwest coast and on some southern islands. If they are active, i.e. subject to coastal processes, they are bare of vegetation and are almost vertical. If they are inactive, they are usually protected by vegetation and appear more in the form of steep slopes. Some cliffs have developed a ramp or a platform in the intertidal zone, sometimes covered with sand. Caves may form where rocks are more susceptible to erosion, for example in the interbedded conglomerates and sandstones on Sentosa."

The picture above shows just a few examples of the caves and cliffs of Tanjong Rimau. A closer look at the caves showed that all, if not most, are more like recesses (and don't extend all the way in) or crawl-spaces. The cliffs, on the other hand, are cut by a lot of grooves and the layers of rock are evident. Pretty :)

This is what the exposed intertidal area looks like during low tide: sandy beach and rocky shore.

More crab sightings! Looking very much like a (movable) piece of substrate was this Common Hairy Crab (Pilumnus vespertillo). Their body has long, silky hairs which trap sediment, enabling these crustaceans to camouflage very well with their surroundings. They are also affectionately known as teddy bear crabs (no prizes for guessing why!).

I was stunned for a moment when I saw this crab. It's another 'first' for me! Have heard quite a lot about it, but have never actually seen one until today. The red colouration of the Mosaic Reef Crab (Lophozozymus pictor) already serves as a warning - stay away! It is the most poisonous crab in Singapore, and cooking it will not destroy the toxins.

We came across a fair number of corals, both hard and soft. This is a picture of a boulder coral - a favid hard coral.

Adding sporadic splashes of blue to the rocky shore were these blue sponges. Though sponges and ascidians look alike, they can be told apart by the absence or presence of oscules (the 'holes' of a sponge through which water is pumped). Sponges belong in Phylum Porifera, a term which translates into 'pore-bearer'.

Nice to see, but not nice to touch though. Sponges typically have sharp microscopic structures known as spicules in their body, which can get embedded into one's skin. Ouch.

This is a sponge, not a soft coral. Thanks SY for pointing it out!

Despite being rather common, I don't think I've seen the Polka-dot Nudibranch (Jorunna funebris) till today! 'Nudibranch' literally means 'naked gills', which is what nudibranchs have. On the posterior end, the feathery-like structures are its gills. Its black-tipped rhinophores are located on the anterior side.

Here's another favid hard coral.

We saw two of these tiny Blue-lined Flatworms (Pseudoceros sp.) today, with WW spotting the first one. Marine flatworms swim by undulating the sides of their body.

Also highly poisonous is the Red Egg Crab (Atergatis integerrimus). It's my first time seeing this crab in the flesh, so to speak.

Curiously enough, I saw two Mosaic Reef Crabs and two Red Egg Crabs. A Floral Egg Crab (Atergatis floridus) also made an appearance. These three crabs hail from the Family Xanthidae, a group of poisonous crabs.

Sponges side by side. They come in a myriad of colours!

I think this is an anemone coral (Goniopora sp.).

I'm not sure what this is. A soft coral?

These favid hard corals were huge.

The rocky shore was covered with a lot of this filamentous green algae.

Looking rather contorted was this leathery soft coral (Family Alcyoniidae).

This is the Phyllodesmium briareum nudibranch which only seems to make its appearance on Sentosa. It harbours zooxanthellae - microscopic single-celled algae - in its body which can photosynthesize. It's mutualism at work for the algae are protected and the mollusc receives nutrients as a product of photosynthesis.

Marine snails have what is known as an operculum - a trapdoor of sorts - which they can use to seal their shell. We saw a few operculums lying on the shore.

Leathery corals can resemble many things. This one here looks like an omelette, don't you think?

We decided to follow the coast of Tanjong Rimau and made our way around. Spotted this Reef Bristleworm which was directly in my path. Lucky I didn't step on it! It's important to always watch where you're going, in order to minimise damage to the shore.

My list of 'firsts' for today had another addition with the sighting of onchidiums (Onchidium sp.). Like the Common Hairy Crab, they resemble the substrate very closely and are difficult to spot unless they move!

Have not seen a fan worm in a long time. This small orange fan worm was found together with the zoanthids in a small pool.

The zoanthids in the pool. They resemble anemones and thus it's easy to get both mixed up.

We could hear and see the tide rushing in.

The rocky shore.

This is a frilly anemone, probably a Plain Frilly Anemone (Phymanthus sp.).

I thought I'd leave these Lightning Dove Shells (Pyrene fulgurans) to the last. Most are dark brown/black with the distinguishing white zigzag pattern on the shell.

Thoughts:
Pretty shells naturally catch the eye of many, and inevitably, many are collected for personal or commercial reasons. When empty shells are removed from the shore, hermit crabs are deprived of a home. Shelled gastropods - live ones - are often killed for their shells and over-collection has played a significant role in the reduction of the number of organisms. What good are shells to us except to admire and display?

On a brighter note, today was a really interesting trip with good company. Thanks KS for organising the trip!


For more about today's trip, check out Kok Sheng's posts at http://wondercreation.blogspot.com/2009/05/first-time-to-siloso-islet.html and http://wondercreation.blogspot.com/2009/05/back-to-first-love-at-tanjong-rimau.html

For more about the islets of Siloso, check out Ivan's posts at http://lazy-lizard-tales.blogspot.com/2009/05/seeing-stars-on-siloso-shore-on-sunday.html and http://lazy-lizard-tales.blogspot.com/2009/05/finds-with-spines-on-siloso.html

SJI Mangrove Walk and Cleanup with Deutsche Bank 050409

It's been a really long time since I last blogged! After 3 weeks with no trips, 5th April was really something to look forward to. It was my first time setting foot on St John's Island (SJI)! Upon reaching our destination, we soon set off. A mangrove walk was first conducted for the employees of Deutsche Bank followed by a subsequent cleanup (brings back memories of the International Coastal Cleanup I participated in last year).

After putting down some belongings at the Tropical Marine Science Institute's (TMSI) pantry, we soon set off! For this trip, I was attached to Robert's group.

The guided walk kicked off with Robert talking about epiphytes. These refer to plants which grow on other plants, like trees, so that they can get better access to light. They are not parasitic though. One example of a common epiphyte in Singapore is the Pigeon Orchid (Dendrobium crumenatum) which can be found growing on roadside trees.

Greenery, away from the city.

Saw many of these pretty flowers growing among the grass and couldn't resist taking a picture of one. (ID?)

After a short walk, we soon reached the back mangroves where a very dead (it looked dried up) Paradise Tree Snake (Chrysopelea paradisi) lay among the grass. Live specimens are able to glide from tree to tree by projecting themselves into the air using a special technique.

The Sea Hibiscus (Hibiscus tiliaceus) and its characteristic heart-shaped leaves. Though there seemed to be no flowers, there were a handful of fruits.

This sight greeted us the moment we stepped into the mangroves. Unbelievable. For every small convenience that we take for granted, like eating packed lunches (above), the environment has to pay the price one way or the other. These bags of rubbish were supposed to be brought to the mainland for proper disposal, but as you can see...

...someone has been burning rubbish right in the mangroves. The stink of garbage lingered in the mangroves with acrid fumes of burnt metal and plastic. Needless to say, it was also an eyesore.

Charred mangrove plants from the burning.

Nevertheless, there was still life around. Looking like a 'botak' broom are these aerial roots. If I'm not wrong, these will grow into prop roots upon reaching the ground.

Developing aerial roots with small lenticels.

Let the cleanup begin! The participants got down to work right away, enthusiastically picking up rubbish.

Fishing nets and other rubbish often gets washed up along shores. Such discarded items often entangle animals, killing them. In total, the group collected 56 kg of rubbish (and that's not counting what the other two groups collected). Great job, everyone! :)

The mangroves of SJI are more or less rubbish-free for now, but within the next few days even, trash will start to accumulate again. This happens everywhere, at our mainland coasts, parks and housing estates. Without cleaners, I don't think Singapore would be clean at all. Green, yes, but not clean. If a small group of people are able to collect so much rubbish within an hour, can you imagine the amount of trash that can be gathered in one minute if each of Singapore's 4 million plus individuals simultaneously picks up a piece of litter? Better still, why not kick the littering habit and start picking up after ourselves...

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...

...an 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).

References:

Wild Fact Sheets of marine life on Singapore shores - http://www.wildsingapore.com/wildfacts/

Acknowledgements:

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

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 sure...it 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:

Acknowledgements:
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]

Notes:

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

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

i. Ron's - http://tidechaser.blogspot.com/2009/03/scorching.html

ii. July's - http://wherediscoverybegins.blogspot.com/2009/03/discover-semakau-landfill-island-8.html

iii. Samson's - http://mantamola.blogspot.com/2009/03/semakau-tidal-walk-8-march-09.html

iv. Meiyi's - http://appreciateandlove.blogspot.com/2009/03/semakau-after-so-long.html

v. Eunice's - http://naturallyours.blogspot.com/2009/03/48-semakau-guiding-w-meiyi-giant-clams.html