Semakau Inter-Tidal Walk on 25 May 2008

Sixty first discovery Posting:

Was up again in the wee hours of the morning to go for another walk at Semakau =P.

Today, I had a group of 'Giant Clams' from Tampines Secondary School with me. Oh, this posting will be short as I need to go pack my bags for a trip to Tioman tomorrow.

So here's a little of the things we saw on today's walk. First 'discovery' is a upside down jelly fish. The top side(picture below).
The underside side(picture below).
Discovery Note:
1. Its name is thus because you will usually find this jellyfish upside down.
2. The upside down position allows zooxanthellae which lives on the underside of the jellyfish to get sunlight so they can photosynthesize.
3. And the zooxanthellae when photosynthesizing shares its food with the jellyfish, while the jellyfish gives the zooxanthellae a place to call home.
4. So they have a symbiotic relationship.

Second 'discovery' is a type of jellyfish which we have spotting in numbers recently (picture below) . This kinda of suggests that this species of jellyfishes are probably seasonal in our waters.
Discovery Note:
1. All jellyfishes have stinging cells. So it is advised not to touch them at all.
2. Most of my friends who have been stung by them before reported a very painful experience.
3. Jellyfishes belong to the phylum of Cnidarians, other Cnidarians include Corals and Anemones.

'Giant Clams' also got the chance to meet themselves, the giant clam! But as the tide was a bit too high today, thus I didn't get a picture of it.

We also had the chance to take the traditional group shot with the knobbly sea star (picture below).
And here's a whole group shot of all the students from Tampines Secondary School who came for the walk today. =)
Thanks to all Giant Clams for being such a wonderful and attentive audience. It was a great day out with you guys! =)

Semakau Inter-Tidal Walk on 24 May 2008

Discovery Posting number Sixty:

It was another early morning where we set off to Semakau land-fill island for an inter-tidal walk. Today, some of us had the luxury of taking the new bus to the forest trail, which we needed to walk through before reaching the inter-tidal area (picture below).

This day, I was assigned to guide a group of ten 'Noble Volutes' which consisted of two families, a pair of friends and a friend from Holland.

And here of some of the things we saw... first 'discovery' is a polka dot nudibranch, Jorunna funebris (picture below)
Discovery Note:
1. 'Nudibranch' means 'naked gills'. The name comes from the flower-like gills found on the back of many nudibranchs. These nudibranchs use the gills to breathe.
2. Nudibranchs are related to snails. Little baby nudibranchs are born with shells, but they lose them when they become adults.
3. Most nudibranchs are carnivores, they eat immobile or small, slow-moving prey. Examples are sponges, ascidians, hard corals, soft corals, sea anemones etc. This particular nudibranch feeds on sponges if my memory serves me correct.

As the rest of the 'volutes' crossed the seagrass lagoon behind me, I quickly grab a group shot (picture below). It looks a bit blur due to the rising sun. Hmm...
Second 'discovery' is a group of common sea stars, here's one of them (picture below).
Discovery Note:
1. Their tube feet are interesting as they are used for walking, handle food as well as breathing, talk about multi purpose!
2. Sea stars get stressed when out of water, this is because while we have blood circulating our bodies, they have sea water circulating their bodies.
3. They are not as common as their name suggests. This is due to past over-collection and habitat lost past and present. So don't take them away from their homes when you see them. =)

Nearby, our hunter seekers also found a flatworm, third 'discovery' (picture below).
Discovery Note:
1. Flatworms are hermaphrodite, which means a flatworm has both the male and female sex organs.
2. And certain species of flatworms engage in penis fencing, in which two individuals fight, trying to pierce the skin of the other with their penises; the first to succeed inseminates the other, which must then carry and nourish the eggs.

We also spotted this ocellated sea cucumber amongst a small patch of seagrass, fourth 'discovery' (picture below).Discovery Note:
1. The popular Chinese name for sea cucumber is haishen, which means, roughly, ginseng of the sea.
2. They have a soft, wormlike body and can range from a few centimeters to even 90 centimeters in length!
3. To repel predators or when stressed, a sea cucumber might expel their innards or ‘vomit’. And if too much of their innards are expelled, they might die off as a result.

Fifth 'discovery' is the star of our walks, the knobbly sea star! Here's a group shot of it with all 'noble volutes' (picture below). The find of the day has got to be this, the cushion star (picture below)! This sixth 'discovery' has not been sighted on our walks since about last year if I'm correct. Wow, what great luck we had! =) The underside of the cushion star (picture below)Discovery Note:
1. They might not have the very distinctive star shape, but they are a kind of sea star!
2. They are not easily seen around inter-tidal areas as they usually lie on the sea floor or further deeper in the waters of reefs.

As we explored around further, one 'volute' spotted this second knobbly sea stat of the day (picture below), which appeared to be saying hello to us. =) It was another great day out at Semakau as I had a interested group and we also lucky to have met ourselves, a real-life noble volute, which I forgot to take a photo of it. =P

Thanks to all volutes again! =)

Sidenote:
I promised one family of volutes to email them a photo shot of them with a knobbly but I appeared to have misplaced their email.=P Could the volutes kindly leave a comment on this posting with their email so that I could email the photo to you. Thanks! =)

Discovery @ Sungei Buloh Wetland Reserve

Fifty Ninth Discovery Posting:

During this week, I was at Sungei Buloh Wetland Reserve (SBWR) almost everyday, from Tuesday (13 May) till today (16 May). Why was I there? It was to guide different groups of students from two different schools, Queensway Secondary and Qihua Primary school.

Anyway, for people who wants to find out more about the reserve, you may visit their website @ http://www.sbwr.org.sg/

In this posting, I'm going to share some of the fauna I saw over these few days.

First 'discovery' is a Malayan water monitor which can be seen if you're lucky (picture below)Discovery Note:
1. Monitors can survive in habitats that wouldn't be able to support other large carnivores as they are cold blooded, that's why they need to bask in the sun.
2. In addition, they eat anything that they can swallow. From tiny insects, to crabs, molluscs, snakes, eggs (of birds and crocodiles) and even other monitor lizards. They even eat rubbish, human faeces, and even dead bodies.
3. The Water Monitor's main hunting technique is to run after prey that it has spotted, rather than stalking and ambushing.
4. Water Monitor Lizards are highly mobile. They can swim, run faster than most of us can run and even climb trees.
5. Like snakes, they have a forked tongue that they stick in and out regularly to "smell" their prey and other tasty titbits.

Second 'discovery' is harder to spot, because usually you will need to listen hard to locate where they are and then look hard to pinpoint their exact location. A cicada (picture below)!
Discovery Note:
1. Cicadas make one of the loudest sounds in the forests.
2. Only males cicadas make the distinctive sound, they make the sound to attract female cicadas to mate with them.

When one walk around the reserve, we advise either silence or to talk very softy if you need. Why? Cause if you make too much noise, you will rouse the third 'discovery' and they will run away. What am i talking about? A Plantain squirrel is what i am talking about(picture below)!
Discovery Note:
1. Plantain squirrels eat mainly fruits and nuts but also snack on insects and other titbits that they come across including bird eggs
2. Plantain squirrels forage mostly in trees and undergrowth and rarely come to the ground.
3. They are active during the day, more so in the morning and evening.
4. They rest in hollow trees and some construct a nest out of leaves and twigs, in tree branches or large bushes.
5. To find out more about the plantain squirrel, click here.

And sometimes if you're really lucky and sharped-eyed, you might spot the fourth 'discovery'. A stork-billed kingfisher (picture below)!
Discovery Note:
1. Stork-billed Kingfishers are the largest Kingfishers found in Singapore.
2. They are rarely sighted because they are shy and less noisy than other Kingfishers.
3. Stork-billed Kingfishers eat mainly fishes, using their large heavy bills to good effect to catch and kill their prey.
4. Want to find out more about them, click here.

And if you are really really very lucky, you will get to see... can you spot it? Let's take a closer look (picture below). A crocodile! Fifth 'discovery'.
Discovery Note:
1. Crocodiles are large aquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia.
2. They feed mostly on vertebrates like fish, reptiles, and mammals, sometimes on invertebrates like mollusks and crustaceans, depending on species.
3. They are an ancient lineage, and are believed to have changed little since the time of the dinosaurs. They are believed to be 200 million years old whereas dinosaurs became extinct 65 million years ago
4. Crocodiles are ambush hunters, waiting for fish or land animals to come close, then rushing out to attack.
5. As cold-blooded predators, they are lethargic, therefore survive long periods without food, and rarely need to actively go hunting.

It was a great experience, going to SBWR for four days straight! Thanks to all students who were in my groups, I hope all of you have had a great time too! =)

Semakau Inter-Tidal Walk on 10 May 2008

Fifty Eighth Discovery Posting:

A very late posting for a walk last Saturday due to many other outings to places like Bukit Timah, Pulau Ubin and Sungei Buloh, hopefully I will find the energy to sit down to blog about some of those trips.

Anyway, for this posting, I would like to blog about two organisms which I seldom blog about and you can find at inter-tidal zones.

First and second 'discovery' are the same (pictures below). Do you think they are plants or animals?

Discovery Note:
1. They are animals called the fan worm or featherduster worm.
2. They are segmented worms.
3. They feed on the tiny particles found in the water.
4. Fan worms live in a flexible and leathery tube which they hide into when they sense danger or they are exposed to the air.
5. Read more about the fan worm on the online Chek Jawa guide.

Third 'discovery' is a giant clam (picture below)
Discovery Note:
1. They are the largest living bivalve mollusc and also known as the bear's paw clam
2. They can weigh more than 227 kilograms and measure as much as 1.2 metres across, and have an average lifespan in the wild of 100 years or more.
3. An interesting symbiosis occurs between a unicellular green alga (Zooanthella ) and the clam. The algae live in the tissues of the clam's siphon and mantle; they are able to obtain the sunlight needed for photosynthesis because the clam lies with its valves opening upward and part of the thick, purple mantle extruding over the shell.
4. In addition, there are crystalloid vesicles on the mantle surface that let in sunlight, thus allowing the algae to live deep within the tissues. The clam uses the algae as a supplementary or perhaps even a major source of food.

It was another great outing as we stayed overnight on the island before the morning inter-tidal walk, and an overnight stay means that we got a chance to see the fireflies! Although it was impossible for me to take a photo of them, it was rewarding enough just to look at them flying around amongst the trees. =)

Changi Beach Inter-Tidal walk on 9 May 2008

Fifty Seventh Discovery posting

Update on 12 May 2008: Upon some feedback, I've modified or added some facts. Discoverers will find a * to a modified or added fact. Thanks to Ria for the info =)

My first time guiding at Changi beach. We had a group of girls from MGS and we were group 'Stingray'. Although we didn't saw ourselves, we did saw lots of other interesting marine creatures.

Here's the sunrise which amazed all Stingrays (picture below), too bad i didn't push the group photo idea further. =P
In this posting, I would focus on a group of creatures called echinoderms. This is because that we saw lots of echinoderms and I was saying the term a lot of times during guiding, so to give a better outlook to all stingrays what echinoderms are, here we go...

Small Warning: This post is a bit info packed, so do be mentally prepared. =)

Discovery Note (Some characteristics of echinoderms):
1. The echinoderms are a group of animals that includes sea stars, sand dollars, urchins, feather stars, brittle stars and sea cucumbers.
*2. They are animals which lack a brain and but possess complex sensing organs.
3. They have a water-vascular system (humans have a blood-vascular system) which pumps water through the madreporite.
4. The madreporite is an opening used to filter water into the water vascular system of echinoderms.
5. And they have tube feet which they use to attach to objects, for protection, as well as to obtain food.
*6. They have 5-sided or pentamerous radial symmetry, this is visible in most sea stars and most can regenerate lost limbs.
*7. Successful regeneration also requires that certain body parts be present in the lost pieces. For example, many sea stars can regenerate a lost portion only if some part of the central disk is present.
*8. The body wall of an echinoderm has a clcium crabonate internal skeleton of dermal ossicles that take many forms. For example, the sea urchin has plate-like ossicles which are fused to form a shell-like test while ossicles in sea cucumbers are reduced to microscopic size.
*9. Another interesting fact about echinoderms is that you can find the presence of a tissue called the "catch connective tissue" which is unknown to exist elsewhere in the animal kingdom. This tissue acts like a kind of molecular Velcro and gives the body wall considerably rigidity. This is the reason why a sea cucumber can feel quite stiff one minute and soft the other.

So our first and second 'discoveries' are sea urchins (picture below).

Discovery Note:
1. Sea urchins belong to the class Echinoidea.
2. Depending on the species, movable spines of various sizes and forms are attached to the body. These spines often are sharp, pointed and in some species even poisonous. The sea urchins use also their spikes to move around.
3. And between their spines are small, pincer-like organs called the pedicelliariae which they use to clean and defend themselves. The pedicelliariae also contains a powerful toxin.

Discovery Note (Ecology and range of echinoderms):
1. Echinoderms are exclusively marine.
2. They can be found in various habitats from the inter-tidal zone down to the bottom of the deep sea trenches and from sand to rubble to coral reefs and in cold and tropical seas.

Discovery Note (Diet of echinoderms):
1. Some echinoderms are carnivorous (for example starfish) others are detritus foragers (for example some sea cucumbers) or planktonic feeders (for example basket stars).
2. Echinoderms are protected through their spiny skins and spines. But they are still preyed upon by shells (like the triton shell), some fish (like the trigger fish), crabs and shrimps and by other echinoderms like starfish which are carnivorous. Many echinoderms only show themselves at night (nocturnal), therefore reducing the threat from the day time predators.

Another type of echinoderms is the sea cucumber, here are two of them (picture below), third and fourth 'discovery'.
Discovery Note:
1. Sea cucumbers belong to the class of Holothuroidea.
2. These echinoderms are generally long and worm-like.
*3. Some sea cucumbers have loaded their body wall with toxic substances to deterrent their predators.
*4. Some sea cucumbers possess sticky threads or tubules, known as Cuvierian tubules, that are ejected through the anus to repel and possibly entangle potential predators.

Discovery Note (Reproduction of echinoderms):
1. Most species of echinoderms are diecious, meaning there are separate male and female individuals.
2. Sexual reproduction involves the external fertilization of eggs by spermatozoa. The fertilized eggs develop into planktonic larvae.
3. The larvae typically go through two stages, called bipinnaria and brachiolaria. They are bilaterally symmetrical and have bands of cilia used in swimming and feeding. As the larvae gradually metamorphose into adults, a complex reorganization and degeneration of internal organs occurs. The left side of the larva becomes the oral surface of the adult, which faces down, and the right side becomes the aboral surface, which faces up. The larvae settle to the sea floor and adopt their distinctive adult radial symmetry.

We also spotted sea stars, a very well-known echinoderm, but before we talk about them further, let us take a look at the brittle star (the small thing below the sea star in the picture below), fifth 'discovery'.
Discovery Note:
1. Brittle Stars belong to the class Ophiuroidea.
2. Related to and like the sea stars, they have five arms and a central disc.
3. As the name suggests, the arms of the brittle stars are rather liable to break. This is actually an escape mechanism. They can regenerate their arms, but slowly.
4. Brittle stars use their arms for locomotion. They do not, like sea stars, depend on tube feet.
5. Brittle stars move fairly rapidly by wriggling their arms which are highly flexible and enable the animals to make either snake-like or rowing movements.

Lastly, let's turn our attention to sea stars (picture below) A knobbly sea star (picture below) A knobbly sea star? A hybrid? Or a totally new species? (picture below)
Discovery Note:
1. Sea stars belong to the class of Asteroidea.
2. Sea stars typically possess five arms that grade into the central disc. There are species which have six or even eight arms!
3. The mouth is located in the center of the underside of the disc and the entire undersurface of the disc and arms is called the oral surface.
4. The opposite, or upper side of the body, is the aboral surface that bears the anus and the ‘madreporite’, which is a small perforated plate through which water is taken into the water vascular system. Another learning point for me!
5. The water is then directed into canals in the arms and then into the tube feet, which extend with the water pressure.
6. The tube feet are very important to sea stars; they are used for locomotion, food collection and respiration. Sea stars move by adhering their tube feet to the substrate and pulling themselves along. They also use their tube feet to catch their prey.
7. Some sea stars are predators that prey on worms, crustaceans and bivalves while some are known to eat decayed plant matters.
8. Many sea stars eat with their stomach outside their body. When doing this, their tube feet will pull the two shells of a bivalve apart. And while still attached to their prey’s body, they extend their stomach out through their mouths into the bivalve shell.
9. They will then release digestive juices which will liquidate the victim and cilia transport the bivalve into the sea star’s body.

It was a great trip as all stingrays were all enthusiastic about everything they saw and attentive when needed =P. Thank you, stingrays, and do note the learning points for me cause they are the mistakes I've made. =)

Reference websites:
1. http://www.oceaninn.com/guides/echino.htm
2. http://www.starfish.ch/reef/echinoderms.html
3. http://tolweb.org/Echinodermata
4. http://animaldiversity.ummz.umich.edu/site/accounts/information/Echinodermata.html
5. David J. W. Lane & Dider Vandenspiegel. A Guide to Sea Stars and other Echinoderms. Singapore Science Center, 2003.

Extra:
a) Read manta's experience to see what his group saw.

Discovery @ St John's Island on 08 May 2008

Fifty Sixth Discovery Posting

While many others were marveling about the stars on Cryene, a few of us decided to pay a visit to the shores of St John's Island. It has been about six months since I last paid a visit to this shore and it was really memorable as it was here that my last camera went swimming and gone with the waves (it didn't got lost, it drown). Anyway...

First 'discovery' was found as we walked down to the rocky areas of the shore. A Flatworm (picture below), one of my friends commented this looked a bit gross (if my memory serves me correct...haha), what do you think?
Discovery Note:
1. Flatworms are hermaphrodite, which means a flatworm has both the male and female sex organs.
2. And certain species of flatworms engage in penis fencing, in which two individuals fight, trying to pierce the skin of the other with their penises; the first to succeed inseminates the other, which must then carry and nourish the eggs.

And if you look carefully on the rocks, you will also be able to spot the onchidium, second 'discovery' (picture below). Can you spot it against the rock?
Discovery Note:
1. They are actually sea slugs, which are molluscs without a shell.
2. They are hard to spot as their skin often match the algae-cover rock, sand and sediment which can get stuck on it also helps to add on to its already great camouflage.
3. They are able to survive out of water as they have lungs which allow them to breathe air.

Another marine creature which you can spot on the rocks is the sea slater (picture below). The third 'discovery'.
Discovery Note:
1. They are sometimes called the sea cockroach due to their appearance.
2. They are not insects, they are actually related to crabs and prawns.
3. They are able to live on the land, as they possess ‘pseudo-lungs’ which helps them to breathe air.

As we walked out nearer to the waters, I spotted the fourth 'discovery', a snapping shrimp (picture below).
Discovery Note:
1. One of their pincers is greatly enlarged. Sometimes, the enlarged pincer can be as long as its entire body.
2. The enlarged pincer has one movable ‘finger’ held apart with a catch. When the catch is released, an explosive sound occurs.
3. When colonies of the shrimp snap their claws, the cacophony is so intense that submarines can take advantage of it to hide from sonar.

It seems that it was a morning of flatworms as we saw around five more flatworms. Here are two of them (pictures below).

The sun slowly rised as we continued our exploration around the shore (picture below)St. John's Island is one of our Southern Islands where one can see coral reefs without having to dive and it is just about a 20 minute boat journey from our business district (picture below). Isn't this something you can't really find around the rest of the world and which we can be proud of?

We also saw slugs. Fifth 'discovery' is a leaf slug (picture below)Discovery Note:
1. Leaf slugs feed on seaweeds by poking a hole in them and then suck out the contents within the seaweed.
2. Due to this feeding behaviour, they also suck in the chloroplast, which helps in photosynthesis for plants. This chloroplast then continues to photosynthesis in the leaf slug which in turn provides the leaf slug with extra food. Talk about supplements!
3. Anyway, that’s why leaf slugs are green; it’s due to the presence of chloroplast.

Sixth 'discovery' was a beautiful copper-banded butterfly fish spotted by HK (picture below).Discovery Note:
1. They have a large ‘false eye’ on its dorsal fin which fools predators into thinking that it is a big fish.
2. And if a predator does attacks it, the fish unexpectedly swim ‘backwards’.
3. Copper-banded butterfly fishes have a long snout with brush-like teeth to suck up coral polyps and small prey from crevices.

What's that someone is taking a photo of??? Let's take a closer look... Oh my, it's a stone fish (picture below) ! And this is the first time I saw this on our shores, seventh 'discovery'!
Discovery Note:
1. As the name suggests, it looks like a stone when it's not moving.
2. This is because it hunts by ambushing its prey. It remains unmoving until one of its preys swim pass.
3. Stone fishes are known to eat small fishes, shrimps and some other crustaceans.
4. They are one of the most venomous fish in the world.
5. Its dorsal area is lined with spines that release a venomous toxin. This venom can cause severe pain with possible shock, paralysis, and tissue death depending on the depth of the penetration. And it can be fatal to humans if medical attention is not given as soon as possible (usually within an hour or two).
6. In summary, you will have a face like it if you stepped on it's spines. =P

Last but not least, the eighth 'discovery', a feather star (picture below).

Discovery Note:
1. These are Echinoderms, Phylum Enchinodermata, like the sea stars, sea cucumbers and sea urchins to name a few.
2. They belong to the class of Crinoidea and one of the most ancient and 'primitive' of ocean invertebrates, with a family tree rooted in almost 500 million years of history!

Another great morning trip thanks to everyone who came and LK for organising. =)

Extra:
a) Check out Manta's blog for many other things which we saw.

Discovery @ Sedili on 1st May to 3rd May 2008

Fifty fifth Discovery Posting

Just the past May day (1st May) till 3rd of May, I was at Tanjung Sutera Resort at Sedili, Johor for a short holiday with friends. It was a place where you could really see NO city landscapes, the horizon and a view of South China sea. Here's a photo of the rocky shores you can find there. This was taken from the resort (picture below).
Here's a closer view of the rocky shores (picture below).
Besides a rocky shore, you can also find mangroves, coastal forests and a sandy beach there. Great getaway for anyone who wants to take a break and those who seek to avoid those very commercialised resorts.

Anyway, for this post, I'll focus on some plants which can be found at the mangroves of Sedili.

So for first 'discovery', we have the flowers of the Teruntum (this common name is for both Lumnitzera racemosa and L. littora, the beautiful flowers you find in the picture below is from Lumnitzera littora).
Discovery Note:
1. Timber harvested from the Teruntum is often used for furniture.
2. You can find this plant usually at the back mangroves (areas which are flooded during high spring tides or very high high tides).

Second 'discovery' is the Chengam, Scyphiphora hydrophyllacea (picture below shows the flowers).
The Chengam's leaves and fruit (picture below)
Discovery Note:
1. This is a shrub that grows both in the mangroves and along sandy beaches.
2. This plant has waxy leaves which reduce water loss through transpiration (A common feature for some plants found in the mangroves, along sandy beaches and coastal forests)
3. This plant has durable wood which is useful for making small, hardy objects.
4. Indigenous people are known to use the warm extracts from the leaves to treat stomach aches.

Third 'discovery' is a butterfly which I think which looks like a Common Tiger at first sight, but after checking, I feel this looks more like a Black Veined Tiger (Danaus melanippus hegesippu), a butterfly I've never seen before (picture below)!Discovery Note:
1. This butterfly can be usually found near mangrove or coastal areas.
2. This species is often confused with the Common Tiger. But if you look closely, the broad submarginal black band in the Black Veined Tiger is broader and this distinguishes it from the Common Tiger. And unlike the Common Tiger, this species has no orange forms. See the difference with a photo of the Common Tiger that I've taken from the NIE Butterfly Garden.

Fourth 'discovery' is the Bakau minyak, Rhizophora apiculata, you can see its flowers in the picture below. A way to tell this species apart from the other Rhizophora species is the red stipule it has and it having dark green leaves (picture below). And of course, the tiny black spots you can find on the underside of its leaves (picture below).Discovery Note:
1. This mangrove tree is a source of timber and charcoal.

Fifth 'discovery' is the Buta-buta, Excoecaria agallocha or more commonly known as 'blind your eyes'. You can see that this tree has white sap and this sap can cause blisters on the skin and even blindness if it comes in contact with the eyes of anyone (picture below)A way to identify this tree is that it has multicoloured leaves where the young leaves are pink while the old leaves turn red. The picture below shows a old leaf.
A 'bigger' picture of the Buta-buta (picture below).
All in all, it was a great getaway for everyone who was there => Thanks to LK for organising this trip and my room mates (RY and SJ) for a fun-filled trip.

Extra:
a) Check out more photos from the trip from SJ's NatureScouter Blog.
b) And for discoverers who wish to find out more about the resort, click here for their website.