Semakau Inter-Tidal walk on 23 Aug 2009

103th Discovery Post:

As I left my house at about 4+am on Sunday morning, it was still drizzling and lighting flashed in the distance. The scene got me a little worried as we were heading out to Semakau yesterday morning (Sunday) and we would not be able to conduct an inter-tidal walk if a lighting alert has been given over the area.

Luckily for all of us, the clouds held on to its water droplets and this resulted with a cool and over-cast sky for a walk at the inter-tidal zone of Semakau.

Here's my group, puffer fish, standing on the trail which brings all visitors to the area through the sea grass meadows (picture below).
After crossing the meadow, we came across this creature staring at us with its pair of eyes (picture below).Our hunter seekers have managed to find us a spider conch, the first 'discovery' (picture below). Discovery Note:
1. As a result of their really nice shells, spider conches are not only collected for food, they are also collected for their shells.
2. Due to this collection, spider conches have been labelled as a 'vulnerable' on the Red list of threaten animals of Singapore.
3. That aside, the movement of spider conches is quite interesting. They make use of a curved, knifed shaped operculum or in short, a 'leg' or 'pole' to pole vault around.
4. The spikes that are found on the shell helps to prevent the spider conch are rolling around after making a 'hop'.
5. Read more about the spider conch @ http://www.wildsingapore.com/wildfacts/mollusca/gastropoda/strombidae/lambis.htm.

The following 'discoveries' of this posting will be star-filled. What do I mean?

First off, our second 'discovery', a juvenile cushion star (picture below) which we have been spotting for the last 2 to 3 months. Hopefully, we will continue to see it in our future visits. =D
Discovery Note:
1. They are more often seen during diving, so it is always a treat to spot them in the inter-tidal areas.
2. They have been found to feed on some species of hard corals. Their diet could also consist of immobile animals, organic particles found on sediments and sea weeds.
3. Read more about them @ http://www.wildsingapore.com/wildfacts/echinodermata/asteroidea/culcita.htm.

Despite being assigned to guide the last minute, I managed to spot several things on my own. Here's one of them, the six armed knobbly sea star which is slowly becoming the new star of our walks (picture below). Third 'discovery'.
Here are all the knobbly sea stars which we have seen for this trip (picture below).Discovery Note:
1. They can only be found on certain islands on the Northern and Southern side of Singapore, therefore, they can be considered as uncommon.
2. Interestingly, their knob patterns can be used to tell one knobbly sea star from another.
3. Like all sea stars, they require sea water for survival, so do not remove them from sea water if possible.
4. Read more about them @ http://www.wildsingapore.com/wildfacts/echinodermata/asteroidea/protoreaster.htm.

Another interesting find would be this yet-to-be identified sea star on Semakau (picture below). As I turned this sea star to view its bottom side, another surprise sprung on me. A tidy brittle star was on the under side of this sea star. It was a pity that I totally forgot to take a photo in the mist of my excitement. By the way, this is the fourth 'discovery'.It was one of the coolest morning walk compared to many other morning walks. What a great way to end the last morning walk @ Semakau. Next month, the tides will change and our trips out to the shores will start in the evenings... Finally, it's thanks to all puffer fishes for being such an attentive group. =D Here's a group photo of everyone (picture above) with the knobbly sea stars.

Extra:
a) Read Tidechaser's entry on this trip: http://tidechaser.blogspot.com/2009/08/semakau-walk-on-23-aug-2009.html
b) Read Manta's entry on this trip: http://mantamola.blogspot.com/2009/08/semakau-walk-on-23-august-09.html

Nature's Tale: You scratch my back, I scratch your back

102th Discovery Posting:

You would have probably heard of the saying, "You scratch my back, I scratch your back". This saying basically means: if you help me, I will help you; we work in a cooperative relationship, etc.

This kind of relationship exist not only in our context but also in the natural world.

Let's use one classic example from our seas to illustrate this: the relationship between the clownfishes and carpet anemones...

Yes, you might be surprise to know that one can find and see clownfishes in Singapore's waters.
Below is a series of photos taken @ Semakau during today's morning there for Project Semakau (http://projectsemakau.rafflesmuseum.net/)

Clown or Anemone Fishes made famous by the Pixar movie, "Finding Nemo", is one of the few organisms/fishes which can live amongst anemones or to be more exact, the tentacles of sea anemones. This is pretty interesting considering the fact that other organisms/fishes would be stung and most probably killed by the sea anemones.
There are basically two theories to why the tentacles of the sea anemone would not sting the clown fish.

From http://www.wildsingapore.com/wildfacts/vertebrates/fish/pomacentridae/amphiprion.htm:
"One theory is that the fish smears mucus from the anemone all over itself thus preventing the sea anemone from stinging it. Another theory is that the mucus of the fish (All fishes are coverd in mucus) lacks substances that trigger a sea anemone to discharge its stingers."
Now let's dive deeper into the "you help me, I help you" or biologist use the term "mutualism" relationship between the two.

Information from: http://www.wildsingapore.com/wildfacts/vertebrates/fish/pomacentridae/amphiprion.htm & http://clownfishandseaanemones.blogspot.com/

Experiments and observations suggest that clownfishes can help to defend their host anemone from specialized tentacle eating fishes like Butterfly fishes. The "anemones might directly ingest particles dropped by the fish or absorb their wastes, which could provide sources of regnerated nitrogen, sulfur, and phosphorous in addition to small prey and plankton they capture."

The host anemone in turn "help" the clown fish by:
1) providing an enemy free space for clown fishes from its predators.
2) acting as a nest site for an anemonefish: the anemonefish lay their eggs on the hard substrate beneath the oral disc of the anemone, where they are tended by the male fish.

A study on done on this very topic also concludes that the presences of clown fishes affects the anemone's growth, reproduction and survival. Here are some of the details (from http://clownfishandseaanemones.blogspot.com/)

• Anemones that harbored anemonefish grew nearly 3x faster than those that did not.
• The average daily growth increment was similar for those anemones that hosted 1 or 2 adult anemonefish, and both these growth rates were significantly greater than for anemones that lacked fish.
• Asexual reproduction was enhanced by the presence of anemonefish: anemones occupied by 2 fish underwent fission much more often (~2x expected rate) than those containing 1 (~expected rate) or 0 fish (~ ½ expected rate)
• Anemones that harbored fish experienced a much lower-than-expected probability of dying than those lacking fish: of 14 deaths, 11 were anemones without fish, 2 were anemones with 1 fish, and just 1 was an anemone with 2 fish.

So these about concludes this posting. Thanks for reading. =D

For further reading:
1) http://www.wildsingapore.com/wildfacts/vertebrates/fish/pomacentridae/amphiprion.htm
2) http://clownfishandseaanemones.blogspot.com/

Semakau over the last weekend of July

101st Discovery Posting:

Over this weekend (25th and 26th of July), together with volunteers from HSBC, schools and public, we conducted a survey for Project Semakau on Sat morning, had a BBQ and night exploration and an exploration inter-tidal walk on Sun morning.

In this posting, I will feature some of critters we encounter.

First 'discovery' would a knobbly sea star (picture below). I only managed to spot one throughout the trip, maybe it's because we are not surveying the side which has more knobbly sea stars. But still I found it strange, as by observation, the habitat is quite similar so by logic there should be more of them. Hmm... well, either there must be a good explanation behind this or I was just unlucky or 'cock' eye...hahaha. Anyway,
Discovery Note:
1. They can only be found on certain islands on the Northern and Southern side of Singapore, therefore, they can be considered as uncommon.
2. Interestingly, their knob patterns can be used to tell one knobbly sea star from another.
3. Like all sea stars, they require sea water for survival, so do not remove them from sea water if possible.
4. Read more about them @ http://www.wildsingapore.com/wildfacts/echinodermata/asteroidea/protoreaster.htm.

Second 'discovery' is a curryfish sea cucumber (picture below). If you ask me, it really looks like the sandfish sea cucumber turned to the dark side...hahaha...

*Update: this (picture below) may be instead a variation of the sandfish sea cucumber... maybe it's really one which turned to the dark side... too much star wars for me.... =P Discovery Note (this is only applicable for a curryfish sea cucumber):
1. Like the sandfish sea cucumber, the curryfish sea cucumber is also harvested for the restaurant trade.
2. According to wildfacts, this is one of the sea cucumbers that is harvested in Malaysia for 'Air Gamat', a local health tonic which is said to aid healing and other ailments. As a result to this, Langkawi now has low numbers of the curryfish sea cucumber.
3. Read more about this sea cucumber @ http://www.wildsingapore.com/wildfacts/echinodermata/holothuroidea/herrmanni.htm.

The third 'discovery' is something that usually occurs in season and right now, it is in season, and that is the upside down jellyfish (pictures below).

Here's the top side (picture below)Here's the underside (picture below)
Discovery Note:
1. The upside down jelly is usually found in its upside down position.
2. This is because there are algae living in the tentacles of the jelly. And these algae shares its food with the jelly in exchange for shelter and probably minerals.
3. Read more about this interesting jelly @ http://www.wildsingapore.com/wildfacts/cnidaria/others/jellyfish/upsidedown.htm.

Fourth 'discovery' is something related to the jelly, this is a leathery anemone (picture below) Discovery Note:
1. This is related to the jelly as they share the common characteristic of having stings which can leave you with a nasty rash or something even worse if you come into contact with them.
2. Like the upside down jelly, this anemone can harbor algae in its tentacles and the relationship they share is similar to the relationship shared between the upside down jelly and algae in them.
3. Do take note that not all jellies and anemones have algae living in their tentacles.
4. One of the way to ID this anemone is to look out for the pink tips it has on its tentacles.
5. Read more about this anemone @ http://www.wildsingapore.com/wildfacts/cnidaria/actiniaria/crispa.htm.

Fifth 'discovery' is a colony of animals, a hard coral (picture below).A close up view of the same coral (picture below).Discovery Note:
1. In simple words, corals are made up of a group of a particular animal called the polyp.
2. Now if you look at the photo (close up view) above, in each 'ring' lives one of this animal.
3. For your info, corals are related to jellies and anemones. Yes, they have stings too, so don't touch them.
4. Corals, jellies and anemones belong to a group of animals called cnidarians. If you are interested to read more about them, you can go to http://www.wildsingapore.com/wildfacts/cnidaria/cnidaria.htm.
5. Now you may be wondering why some corals have bright colours. This is probably due to bioluminescence.
6. Basically, the idea behind this is close why we apply sunblock when we visit the beaches, to prevent getting sun burnt. To be a little specific, this colouring they have prevents the corals from certain wavelengths of colours which could harm them.

Besides hard corals, you can also see a number of soft corals over at Semakau, here's some of them (picture below).
Finally, the sixth 'discovery' is a firefly (picture below)! I do apologize for the blur picture, I do admit I should have taken more photos of this really interesting insect.
Discovery Note:
1. Fire flies are able to chemically produce 'cold light' which contains no ultraviolet or infrared rays.
2. These lights which they produce are used either for attract mates or prey.
3. Although more commonly called fire flies, they are actually winged beetles and NOT flies.

Living Shores of Semakau

100th Discovery Posting:

Visitors or participants to Semakau with RMBR would always be assigned to a group name (participants to St John Island's inter tidal walk and students participating in other shore walks organised by RMBR would probably get these as well). And if you have ever wondered where these names come from, the names are actually from a series of 18 badges. And these 18 badges features the flora and fauna that can be found on Semakau and also on other shores of Singapore.

In this posting, i will feature all the 18 badges and have tried to at the same time show you how the real animal or plant look like in real life. What do i mean by that? Just look at the picture below to get an idea.
This (picture above) is a land-hermit crab. I have never personally seen it at Semakau, that is probably because I never made any effort to look for one. This particiular individual is from Sister's island. Maybe I should spend some time to look for a land hermit crab over at Semakau when I have the time.

Next up is the mangrove badge (picture below).One can find a great number of mangrove trees on Semakau. The mangrove survey done during Project Semakau (still ongoing) has yield results informing us that Semakau is a home to some of the rarer species of mangrove trees found in Singapore, one example is the Avicennia marina.

And on Semakau and other places, you can usually spot a number of fiddler crabs near the roots of mangrove trees and around sandy areas (picture below). Another animal you might spot near mangrove trees would be the mudskipper (picture below)And sometimes if you're lucky, you might even spot a horseshoe crab (picture below).By the way, it would be good to note that there are 2 types of horseshoe crabs you can find in Singapore. One is the mangrove horseshoe crab, the other is the costal horseshoe crab. The most easy way to tell one apart from another is by feeling their tails. The mangrove horseshoe crab's tail is round in cross-section while the coastal one is triangular-like in cross-section.

Next up is the upside down jellyfish (picture below). They are mostly found in an upside down position as there are algae living mostly in the upside down section of their bodies. The algae would share any extra food it makes and in return, the upside down jelly fish provides shelter and minerials for the algae. This kind of 'you help me, I help you' relationship is also seen in other marine creatures such as corals and ... giant clams (picture below).In our safety briefings for any inter tidal walks, we would always ask our participants to let us (the guides) to walk first and want them to follow our trail. This is mostly because there are creatures out there which can cause one harm if stepped on. One example would be a blue-spotted fantail ray (picture below). It would give you a really bad sting using its one or two venomous sting on its tail.
There are also some interesting and nice looking shelled animals featured on the badges also. One of them would be the noble volute (picture below).The other would be the spider conch (picture below).And if you look closer at the badge and photo above, you would see that the spider conch actually has a pair of eyes!

Besides the two shelled animals, there are also other creatures which we and our participants find them adorable. One example would be a nudibranch, which is a kind of sea slug (picture below).
The seahorse (picture below)And the clownfish aka NEMO (picture below)Next up is the octopus (picture below). You might not know this, but octopuses are actually quite common on our shores. They are just not seen so often as they are more active in the dark.

And of course, how could the stars of any inter tidal walk, the Knobbly sea star, be missed out frmo the series of badges (picture below).
Right now, although I have the whole collection of all 18 badges, I do not have the photos or nice photos of all the them. Some of them inculde the puffer fish (picture below)The great-billed heron (picture below)
And the hawksbill turtle (picture below)You might be wondering if there are any sea turtles in our waters. Let me answer give you the answer to the question. It is a big YES. Some of my friends have actually seen them with their own eyes on Semakau before.

So that is all the 18 badges for you. But before I end this post, you would find a series of group photos from the participants I've lead for yesterday and today. I've uploaded them so they could download them for memories and also as a memory for me. =D

Semakau Inter-Tidal walk on 12 June 2009

Ninety Ninth Discovery Posting:

This morning, I visited Semakau land fill island again with RMBR volunteer guides and participants from various walks of life for another guided walk at the inter tidal area of Semakau.

And like yesterday, the sun greeted us as we walked leisurely towards the forest trail which would bring us to our destination (picture below).
Besides chasing our sleepy moods away, the sunrise also provided us a great photo opportunity (picture below).This scene (picture below) will be the sight and also our destination once one gets through the forest trail. The inter tidal area of Semakau.Today, the group I lead was called Upside down Jellyfish. And here's everyone standing in the seagrass meadow (picture below).
And after crossing the seagrass meadow, our first 'discovery' was marked out by our hardworking hunter seekers, two common sea stars, one on top of another (picture below). Discovery Note:
1. This unique positioning pattern is actually a part of the common sea stars' mating ritual.
2. The male, which is usually smaller in size, will be found on top of the female with its arms alternating with hers.
3. The common sea stars do not external reproduction organs. Therefore this behaviour is to increase the chance of exterior fertilisation.
4. Read more about this and the common sea star @ http://www.wildsingapore.com/wildfacts/echinodermata/asteroidea/archaster.htm.

As the tide today wasn't low enough for us to look at the resident giant clam, we did see the juvenille giant clam around the coral rubble area (picture below). Second 'discovery'.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.
5. Read more about them @ http://www.wildsingapore.com/wildfacts/mollusca/bivalvia/tridacnidae/tridacnidae.htm.

Our hunter seekers also managed to find 2 knobbly sea stars today. And this was after some hard work and much walking around (picture below). Kudos to our hunter seekers. =DWell, we never forget to take a traditional group photo with the knobbly (picture below).Next up, third 'discovery' is the sea slug which most of our visitors use the word 'cute' to describe it. A polka-dot nudibranch (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.
4. To protect themselves, some produce distasteful substances, toxins and even acids. They advertise this with bright warning colours. Others are camouflaged to match their surroundings. Those that eat colourful creatures such as sponges or corals, may themselves be colourful to match their prey. Being small and flat, they can also easily hide in narrow places.
5. Read more about them @ http://www.wildsingapore.com/wildfacts/mollusca/nudibranchia.htm.

Fourth 'discovery' is another piece of finding from our wonderful hunter seekers, a sea horse (picture below). Discovery Note:
1. They are hard to find as they are well-camouflaged.
2. Do you know that a seahorse is actually a fish? Yes, it is, but instead of having scales, they have an inflexible armour of overlapping bony plates.
3. A seahorse cannot swim faster because it doesn't have tail fin and pelvic fins like other fishes, thus it is well-camouflaged. But they can make a short burst of speed if in danger.
4. They may look harmless, but they are actually quite voracious predators. It sits in wait and ambushes on any tiny animals that drifts or wander by.
5. They have a very simple digestive system (no stomach) thus they need to eat almost constantly. Baby sea horses are known to eat thousands of tiny shrimps in a day!
6. And of course, the most well-known fact of the sea horse is that the male can get 'pregnant', this is because the female seahorses lay eggs in the pouch of a male seahorse and it is in their where the eggs will be fertilized and then the male seahorse will carry them till the eggs hatch.
7. Read more about it @ http://www.wildsingapore.com/wildfacts/vertebrates/fish/syngnathidae/comes.htm.

As we headed back, we encoutered this long queue over at the sea grass lagoon. I wonder what was making everyone stop there? After some simple investiagation, i discovered that they were actually stopping to take a closer look at a spider conch. The fifth 'discovery' of this posting (picture below).Discovery Note:
1. As a result of their really nice shells, spider conches are not only collected for food, they are also collected for their shells.
2. Due to this collection, spider conches have been labelled as a 'vulnerable' on the Red list of threaten animals of Singapore.
3. That aside, the movement of spider conches is quite interesting. They make use of a curved, knifed shaped operculum or in short, a 'leg' or 'pole' to pole vault around.
4. The spikes that are found on the shell helps to prevent the spider conch are rolling around after making a 'hop'.
5. Read more about the spider conch @ http://www.wildsingapore.com/wildfacts/mollusca/gastropoda/strombidae/lambis.htm.

Lastly, the sixth 'discovery' is a juvenile cushion star spotted by the participants from KS's group (picture below).
Discovery Note:
1. They are more oftenly seen during diving, so it is always a treat to spot them in the inter-tidal areas.
2. They have been found to feed on some species of hard corals. Their diet could also consist of immobile animals, organic particles found on sediments and sea weeds.
3. Read more about them @ http://www.wildsingapore.com/wildfacts/echinodermata/asteroidea/culcita.htm.

In conclusion, today was another great day out, as the jellyfishes were an attentive and interested group. Thank you, everyone! =D

Extra:
a) Read KS's posting for this trip: http://wondercreation.blogspot.com/2009/06/semakau-public-walk-on-12-june.html