Discovery @ Sentosa on 9 Feb 2009

Eighty Seventh Discovery Posting:

On the just past Monday, together with G, we visited Sentosa. Actually this was suppose to be some sort of a reece trip for an upcoming eco-camp, but I used this chance to also to take a long-awaited look at the shores of Sentosa again. Especially the area where the construction of the Sentosa IR is going on nearby (picture below).
If you look closely at the photo, you will spot a huge barrier like object. I suppose that is a barrier set up by the developers of the IR to prevent silt and other particles from destroying the life found on the side I was exploring. And I have to say it is working to quite a good extent, as most of the corals which I have seen before the development began are still around (I might be wrong in this, so do feel free to amend on what I have written here).

And first 'discovery' is two different species of hard corals (picture below). Despite going through some training on the ID-ing of corals, I still suck at it...anyway, Discovery Note:
1. Corals are animals.
2. They belong to a group of ancient and simple group of animals known as Cnidarians (pronounced as "nai-day-rians") Jellyfishes and sea anemones are also from this phylum Cnidaria.
3. Cnidarians are aquatic and they share a common and unique feature of having stinging cells used for protection and catching of prey.
4. They are generally composed of more than one tiny animal, probably tens / hundreds / thousands of them in one coral structure, that's why you have heard of "Coral Colony".
5. These tiny animals are called polyps which feed on microscopic plankton or small organisms.
6. Coral hosts colourful zooxanthellae algae in them.
7. These algae form a symbiotic relationship (one which they help one another) with the corals.
8. Through photosynthesis, these algae generate "food" for themselves and pass the extras to the coral which will help to the coral to grow into a larger colony. In return, the coral provides a "home" for these algae.
9. Thus, corals are usually found in clear and shallow waters, as sufficient sunlight is essential in photosynthesis.
10. Read more about hard corals @ http://www.wildsingapore.com/wildfacts/cnidaria/coralhard/coralhard.htm.

As I walked around the area, I soon came across a little heron (ID made known to me by Nov, thanks!) and it's second 'discovery'.
Discovery Note:
1. Little herons' diet mainly consist of small fish and crustacea (mainly crabs). That explains why I saw one at Sentosa.
2. They also feed on amphibians and insects and any other edible tidbits, including small mammals.
3. They tend to roost alone (stay alone) and are highly territoral.
4. Read more about them @ http://www.naturia.per.sg/buloh/birds/Butorides_striatus.htm.

A surpirse find of the day would be two sand dollars, third 'discovery' (picture below).
Discovery Note:
1. Living sand dollars are coated in fine, harmless spines that made them very velvety.
2. The spines are movable and are used to dig into the sand or move around.
3. The dense layer of spines also helps to keep off sand and silt so there is a flow of oxygenated water across the body.
4. Read more about them @ http://www.wildsingapore.com/wildfacts/echinodermata/echinoidea/sandollar/sandollar.htm.

I especially love walking along this stretch of the Sentosa shores... (picture below)
Reason being that I can look at the interesting rock structures created by the waves and the weather (picture below). After walking pass one of my favourite parts, we came to another part of the natural shore on Sentosa and bumped into two teachers from RJC who were reecing to check if the place is suitable for a biology class session. It's heartening to hear that they are thinking of introducing this part of Singapore to their students, as not many students know that our waters are actually very much alive.

The exploration soon continued and soon came the fourth 'discovery', a fan worm (picture below).Discovery Note:
1. They are segmented worms like earthworms.
2. The feathery things are actually its modified tentacles which helps it to gather food.
3. They feed on detridus and other micro organisms in the seas.
4. Read more about them @ http://www.wildsingapore.com/wildfacts/worm/polychaeta/sabellidae.htm.

Although there was no slugs sighting, there were a number of crab sightings though, fifth, sixth and seventh 'discovery' are crabs.

A Hairy Crab (picture below)
Discovery Note:
1. The hairs of the hairy crab traps sediment so it blends 'almost' perfectly with its surroundings.
2. We also call this crab the ‘teddy bear crab’. =)
3. The hairy crab eats seaweeds and poisonous zoanthids, which makes the crab mildly poisonous too!
4. This is NOT the same hairy crab you eat as a seafood.
5. Read more about them @ http://www.wildsingapore.com/wildfacts/crustacea/crab/pilumnidae/pilumnidae.htm.

A red egg crab (picture below) Discovery Note:
1. Red Egg crabs are highly poisonous and contain toxins which are not destroyed by cooking.
2. Since other animals don't particularly want to eat this crab as it is poisonous, it is slow moving and doesn't really bother to hide.
3. Read more about them @ http://www.wildsingapore.com/wildfacts/crustacea/crab/xanthidae/integerrimus.htm.

A mosaic crab (picture below)Discovery Note:
1. This is one of the most poisonous crab in Singapore.
2. Thus, I give the strongest advice not to eat this, although biologists say that everything can be eaten once, but they do not mention what will happen to you after that meal...
3. Did I mention that the toxins cannot be 'destoryed' by high temperature...
4. Read more about them @ http://www.wildsingapore.com/wildfacts/crustacea/crab/xanthidae/pictor.htm.

As they always say, time flies when you're having fun. Thus very soon, it was time to leave the inter-tidal zone to avoid being washed away by the waves and also the time to enjoy a beautiful sunset (picture below).PS: Thanks to G for the company and making the trip laughter-filled. =D

Sentosa Walk with NHC on 6 June 2008

Sixty Second Discovery Posting:

Today is the first anniversary walk for the Naked Hermit Crabs and we were back at the place where we conducted our first guided walk, the natural shores of Sentosa!

I always enjoyed the view of the natural shore of Sentosa (picture below). Today's tide was also really low that I could see parts of the shore which I've never seen exposed before. Wow!
Anyway, my role was a guide today and two fathers, David and Edwin (if i remembered your names correctly) with their kids (Daniel, John and Madeline) was in my group.

Here are the kids with a 'wave constructed' cave around the area (picture below).
We were really lucky today to see a pair of coastal horseshoe crabs which were most probably washed up by the waves (picture below). First 'discovery'!
Discovery Note:
1. Horseshoe crabs have known to 'roam' the earth since days even before the dinosaurs was around, so scientists calls them 'living fossils'.
2. Although they are called horseshoe crabs, they are not related to crabs. They are actually more related to spiders and scorpions.
3. There are two types of horseshoes crabs which we can find in Singapore, the mangrove one (circular tail) and the coastal one (the trianglar tail)
4. The tail is not venomous and is not used as a weapon. It is merely used as a lever to right itself if it is overturned. If you see an upside down horseshoe crab struggling with its tail waving around, do give it a helping hand. It will not hurt you.
5. The blood of the horseshoe crab is blue, as it is copper-based.
6. Their blood is able to clot easily when it detects bacteria, so their blood was harvested for these purposes until a team from NUS's department of Zoology has cloned a substance to replace using horseshoe crab's blood. Read more about it here.

Second 'discovery' was a find by our hunter seekers. A flat worm (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.

And we also saw lots of turban shells. Here's one of them, third 'discovery' (picture below).
Discovery Note:
1. The door to the shell opening (operculum) is thick and rounded.
2. The hemi-spherical operculum is called a 'cat's eye'.
3. These ‘cat’s eyes’ are sometimes used as buttons.

During our walk, we also spotted lots of hairy crabs, red, green egg crabs and a mosaic crab which are all poisonous! We also saw a few black sea cucumbers and of course barnacles! But I forgot to take photos of those. =P

Anyway, here a group shot of everyone, inclusive of guide (picture below)And as our walk came to an end, the tide was also rising. Wow, look at the difference compared to the first photo (picture below).Finally, it's thanks to David, Edwin and the kids of course for making this trip another interesting and fun outing. And of course, everyone who turned up! =)

Sentosa Walk with NHC on 27 Oct 2007

Twenty-ninth discovery posting:

The NHC (Naked Hermit Crabs) were out in action again, of course with our clothes on. =P

This time, we made our presence on Sentosa!
Where were we heading, here?
Nope, this is where we were heading with members of the public who signed up with us for a guided walk at the natural shore of Sentosa.
But my role for the day was not a guide, i was holding the role of "If you don't see any thing, blame me" tag aka hunter seeker... which means i was to look for interesting things for the visitors to view before they appear. Here's one of the things i do if i found something. (picture below)
A headache which most inter-tidal hunter seekers face is that the tide has not gone down to a level which i could easily spot things. This was the case, thus if any participant who was there on the day and wondering why we were taking a long time before you came to the shore. It was because that the tide hasn't reach a level which was low enough and i only managed to find a couple of beautiful shells due to the same reason.

Second headache for hunter seekers is, "I cannot find anything", thus a never-give-up approach and "i need more help" plea. hahaha.

Thus, Helen was on the scene to help me out. And look what she found. First 'discovery', a copper-banded butterfly fish! (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. They have a long snout with brush-like teeth to suck up coral polyps and small prey from crevices.

And the kids on the family trail led by Marcus found this, second 'discovery', a mosaic crab! (picture below)
Discovery Note:
1. This is one of the most poisonous crab in Singapore.
2. Thus, we give the strongest advice not to eat this, although biologists say that everything can be eaten once, but they do not mention what will happen to you after that meal...

As we found more things, one swimming crab, one leaf slug, one discodoris nudibranch, a hairy crab (which ran away), the groups on the adventure trail (longer route which led participants trek on the rocky shores of Sentosa) soon arrived to what i was (picture below).
And hearing them say, "Hey, an octopus!", i went over to take a peek. Here's the third 'discovery', an octopus (picture below)

Discovery Note:
1. Octopuses are characterized by their eight arms (not tentacles), usually bearing suction cups.
2. They have a relative short life span, and some specials live for as little as six months.
3. They have three hears! Two pump blood through each of their two gills, while the third pumps blood through the body.
4. They are also highly intelligent, probably more intelligent than any other order of invertebrates (any animal without a spinal column).

The participants also spotted another leaf slug amongst the seaweeds, fourth 'discovery' (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…
4. I wonder what will happen to us (humans) if we can do the same thing as the leaf slugs, would we turn green…hahaha

Anyway, by this time, i was kinda of free to move around and some Crabbies in action. Here's Ron (in the centre) in guiding mode (picture below).

And as this was a evening walk, we were treated to the wonderful scene of a sunset (picture below). What a way to end the walk!

Thanks to everyone who came for the walk, all NHC who were presented and of course, Helen, who made my job a whole lot less stressing... =)

Extra: You can read Sijie (new naked crabbie) 's bog entry on his OJT and many other things he saw on the adventure trail, just click here.

Naked Hermit Crabs goes on an adventure on 7 June 2007

Ninth Discovery Posting:

Unlike yesterday, today looked like a splendid day for a walk on the Sentosa shores (picture below).
Today's the third day straight for the Naked Hermit Crabs on Sentosa and this morning was a guides and friends day and exploring the adventure trail was our objective of the day.

As I walked towards the starting point of the adventure trail, a peahen and its chick was also doing their morning walk (picture below). Hey, my first 'discovery' of the day.
Discovery Note:
1. Do you know that the male is called a peacock while the female is a peahen?
2. So instead of using peacock as a term to refer to both sexes, use peafowl.
3. Peacocks are best known for their extravagant tail, which it displays as part of courtship.
4. There are generally 2 species of peafowl, the Indian Peafowl and the Green Peafowl.
5. The Indian Peafowl is the nation bird of India.
6. The Green Peafowl is listed as vulnerable to extinction due to hunting and habitat lost.

Before we descended to the starting point, the walk had already unofficially began with Robert giving an introduction on the flower of Sea Poison Tree (picture below) and the tree itself. Second 'discovery'.
Discovery Note:
1. It is a large tree that grows on sandy and rocky shores.
2. The flowers are delightful puff balls of white stamens tipped with pink. They open at night and attract large moths and nectar-feeding bats with their heavy scent.
3. The next morning, the flower stamens are usually found strewn beneath the tree.
4. The seeds and other parts of the plant are pounded, pulped or grated to release the poison which can be used to stun fish in freshwater streams. But please do not do that.
5. It is among the plants that host the magnificent Atlas Moth.

And just nearby was a kapok tree (picture below). Third 'discovery'!
Seed pod of the Kapok Tree (picture below).
Discovery Note:
1. The Kapok tree is an emergent tree of the tropical rainforests, and is often described as majestic as it can grow to a height of 45 meters or more.
2. It is a native plant from South America.
3. The brown seeds are round like peas and are found in pods.
4. The seed pods are woody, smooth and pendulous, with a light green colour. They will burst open while still on the tree after the leaves have fallen. Inside a whitish cotton like fiber surrounds the brown seeds.
5. These white cotton like fiber can be used in pillows and mattresses.

Note:
These trees actually play an important part within the ecosystem of the forest. Click here to find out more.

Here was almost everyone (minus me) on the shores heading towards the branching corals found nearby. Corals so near the city, is it possible? Read my previous entry to find out.
As we headed towards the branching corals, this attracted our attention. A carpet anemone (picture below)! Fourth 'discovery' of the day.
Discovery Note:
1. Carpet anemones of the same species may have different colours. These colours are caused by the symbiotic algae that live in their tentacles.
2. At low tide, the oral disk shrinks greatly to reduce the area that is exposed to the drying air.
3. When it is really hot and dry, the entire oral disk can be retracted completely into the ground. 4. This can also happen when it rains heavily at low tide.

And lying nearby was a moon snail (picture below), let me count, this is the fifth 'discovery'.
Discovery Note:
1. Moon snails are able to inflate its body with seawater as it emerges from the shell and the fully expanded body can be much bigger than its own shell.
2. The Moon snail is able to warp its huge body around its prey to suffocate it.
3. It can also secrete an acid to soften its victim’s shell. A hole is then eventually created in the shell with its radula.
4. The Moon snail generally feeds on snails and clams.

Continuing our trail, this staircase (picture below) came into view. What is it?
Ron then said that this might be a old jetty. Evidence? Look at the picture below.
Walking on , i then saw this Angsana tree (picture below) which i missed during my trip here yesterday. Sixth 'discovery'.
Discovery Note:
1. The Angsana tree is native to the southern part of the east coast of Peninsular Malaysia and was introduced into Singapore in the early 19th century.
2. However, mature trees are known to have a weak structure, and break easily, especially during stormy weathers. So don’t stand near to an Angsana tree during a storm.

Well, the Angsana tree was actually an indication that the trail from there on will start to get rocky (picture below).
Some people might think what life can we find amongst the rocks. Well, my seventh 'discovery' would be one example. The dwarf turban snail (picture below).
Bottom view of the dwarf turban snail (picture below)
Discovery Note:
1. The door to the shell opening (operculum) is thick and rounded.
2. The hemi-spherical operculum is called a 'cat's eye'.
3. These ‘cat’s eyes’ are sometimes used as buttons.

With a ratio of guides outnumbering friends by 3:1, naturally our progress would be slow, as everyone was exploring the flora and fauna along the shores. We were behind schedule for about 20 minutes before hitting the second part of the trail where some have went there earlier to look for things. Here are some of the things they've found.

Eighth 'discovery'. A polka-dot nudibranch (picture below).
Discovery Note:
1. There are 3000 described species of nudibranchs worldwide.
2. They can be found from the lower inter-tidal zone to depths of over 700 meters.
3. They can be found all over the world, from the British Islands, the tropics and even the Antarctic.

Ninth 'discovery' was a unknown fish (picture below).
Discovery Note:
1. This fish has a false eye near its tail.
2. This fish was able to change colour from a electric blue to a almost black colour. We are guessing that it changes into the almost black colour when disturbed or when it senses danger, so that it can escape easily.

Note:
A photo of the same fish when it is in the electric blue colour (picture below).
Tenth 'discovery' was a mosaic crab.
Discovery Note:
1. This is one of the most poisonous crabs we can find in our waters.

Seeing that the tide was coming in, all of us had to leave the shore reluctantly.

but, We, the Naked Hermit Crabs would be back at Sentosa! So it's see you soon, Sentosa~

Final entry words: Thanks to all the Naked Hermit Crabs, friends of NHC and participants for making these three days an wonderful experience. The waves will wash away our footprints but memories will remain. =p

Adventure with Naked Hermit Crabs on 6 June 2007

Eighth Discovery Posting:

(Entry @ 8 June 2007: Managed to get the ID for the unknown nudibranch. Thanks CH!)
(Entry @ 7 June 2007: Added information about the polyp. Like to thank Ria for the info. thanks, Ria)

First of all, i apologize for the mistake made for the last discovery entry, the date should have been 5 June not 6 June. Must have been the excitement and tiredness from the walk yesterday. =p

Anyway, back to this entry.

This morning when we reached Sentosa, low hanging clouds enveloped the sky and the wind was blowing stronger than usual. It looked like it would rain anytime and everyone was hoping that the weather would hold and not rain.

Very soon, the participants arrived and with the weather in a stasis mode, we proceed to our different trails. Today, I was heading for the adventure trail with Ron being the head guide and Robert and Andy being hunter seekers cum co-guide.

As we descended upon the shore, Robert soon spotted a rare find. A ghost crab (picture below and First 'discovery') seen during daytime? Upon observation, we found that one of its pincers was caught onto a stray fishing line or net line. With some effort, Ron, Robert and Andy managed to free the crab and it 'disappeared' from sight with the first sight of 'freedom'.
Discovery Note:
1. These crabs are called ghosts because of their ability to disappear from sight almost instantly, scuttling at speeds up to 16 km per hour, while making sharp directional changes.
2. Ghost Crabs live in deep burrows above the waterline.
3. They come out of their burrows to feed at night.
4. They are known to eat small particles of dead plants, animals, algae and micro-organisms.

Although being so close to the city (picture below), we actually have shores filled with life.
These branching corals (picture below) were actually growing very well even being so near our city area. Second 'discovery' of the day also made me ponder about that if the development on Sentosa would rob us of these wonderful nature sights.

People have been talking about saving our forests, how about saving our corals too. They are forests also, the forest of the sea.
A closer up shot the corals (picture below)
Discovery Note:
1. Branching corals are characterized by having numerous branches, usually with secondary branches.

As we walked the shoreline, Ron pointed out some flora which were along the way. Here's a sea hibiscus (picture below). Third 'discovery'.
Discovery Note:
1. This fast growing tree commonly grows along the seashore and back mangroves.
2. The yellow flowers open in the morning (after sunrise, about 9 am) and turn orangey brown before falling on the same evening or the following day.

Since it was an adventure trail we were going on, the walk naturally would be a bit more 'challenging'.

We had to navigate our ways through rocky paths, looking twice on where we step to ensure that we don't kill any life and an objective of reaching the other part of our trail on time.
(2 pictures below to record the trail we were on...)

Soon we came to one of our stops. A cave (picture below)!!! Fourth 'discovery'!
Hey, how often do we get to see a cave in Singapore anyway. =p
Discovery Note:
Tool of construction: waves
Estimated Time of construction: Over hundreds of years
Method: Constant ‘attention’ from the waves on the cliffs everyday
Progression: Little nooks to Caves!

As we passed the numerous small tidal pools along the way, our hunter seekers pointed out this cowrie (picture below) in one of them. Fifth 'discovery' of the day.
Discovery Note:
1. They have shells but it is usually covered completely by their mantle.
2. This mantle prevents algae and encrusting animals from settling on their shell.
3. They feed on algae and seaweed.

Moving further down the trail, we soon came to another wonderful creation by the waves of the sea (picture below).

On the sides of another tidal pool, volcano barnacles were spotted. Here's one of them (picture below) and this is the sixth 'discovery'.
Discovery Note:
1. These animals actually start life as free swimming larvae.
2. When it finds a good spot on a rock to settle down permanently, it will glue its head down on the rock and produce a shell around itself.
3. Volcano barnacles are usually found where there is greater water movement.

Reaching the second part of our trail, we were treated to the sights of more corals. A leathery coral or sometimes we call this, 'Dead man's fingers' (picture below). Seventh 'discovery'!
Discovery Note:
1. Leathery soft corals are made up of a colony of animals.
2. These animals are called polyp. They look like a very tiny sea anemone with a long body topped with tentacles.

The picture below shows a close up shot of a polyp (picture below)
Note:
Not all polyps look like this, this is just one example of many.
By the way, their tentacles will only come out if under water.

Addition Note on picture above (from Ria):
1. Hard coral polyps have smooth unbranched tentacles usually 6 or multiples of 6, while soft corals have branched tentacles, usually 8 or multiples of 8.
2. So the picture above shows polyps from a hard coral.

Ninth 'discovery' was star barnacles (picture below) which were everywhere on the cliffs we walked past.
Discovery Note:
1. When not under water, a set of plates shuts the opening in the middle of the shell of the barnacle, forming an airtight seal.
2. When under water, the barnacles will open their plates and extend their feathery, segmented legs for feeding on plankton.

And very soon, we came to the 'famous tourist spot' on Sentosa (picture below).
Approaching the last station of our trail, we were treated to a galore of finds by our hardworking hunter seekers.

Tenth '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.

Eleventh 'discovery', a unknown nudibranch (picture below) to me. Could someone tell me the ID of this nudibranch? Thanks!
(Entry @ 8 June 2007: ID for this is phyllodesmium briareum nudibranch. Thanks to CH for providing the ID!)
Twelfth 'discovery', a pair of marginated glossodoris nudibranch (picture below).
Note:
Discoverers, can you recall what are some facts about nudibranches?
Test yourselves and read my other discovery entries for discovery notes on nudibranches to check your answers.

Thirteenth 'discovery' was a brittle star (picture below).
Note:
This brittle star is about 1cm in diameter!

Discovery Note:
1. Like sea stars, they have five arms, spine and tube feet.
2. The brittle star may purposely throw off an arm to distract predators. They can regenerate their arms, but slowly.

After viewing all the discoveries, our hunter seekers released them back to where they were found, back to the wild and their homes.

Finally after a two hour plus walk, we managed to complete the adventure trail in one piece and still full of energy. Prove? Look at our group shot together (picture below). We've done it!Lastly, it's thanks to everyone who joined us today, all Naked Hermit crabbies and of course the weather for making our walk a 'sweat' free event. =)