Monday, March 10, 2008

Semakau Inter-Tidal Walk on 9 March 2008

Fifty First Discovery Posting

Singapore. An island with one of the most busy ports in the world (picture below).
It is also our fortune to be able to view reefs within an hour of boat ride from our city at our southern islands. Yes, we have coral reefs in Singapore! Read more about them here.

Yesterday, we were on Pulau Semakau ,one of these special southern islands, where we can view coral reefs without having to dive (picture below). Do you know that this island is also first offshore landfill island and last landfill in Singapore? Read more about it here.
My job again was a hunter seeker, together with CH, Robert and HW. Basically, we are in charged of finding the interesting flora and fauna for our visitors. Here's us moving past the forest trail(picture below). Upon exiting the forest trail, Robert spotted a net off the side. And a closer look brought a shock for us, as there were two trapped horseshoe crabs which were alive! Immediately, we sprung into action and released the first 'discoveries' from the net (picture below). 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 but 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 triangular 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.

After the rescue 'mission', we proceed to start our seeking. And very soon, we managed to find the resident gigantic carpet anemone (picture below), second 'discovery'.
Discovery Note:
1. For self defence and preying purposes, they have stinging cells in their tentacles which will release or 'shoot' small 'needles' when upon contact. So I won't really advise you to touch them although our skin might be 'thicker' than most marine creatures. This is to prevent you from getting stung.
2. They lack an anus, so they split out any indigestible food through its mouth.

Third 'discovery' is a flatworm (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.

Fourth 'discovery' is something that looks a little like a flatworm. But it's not, this is a kind of sea slug, a Chromodoris 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.

Fifth and sixth 'discoveries' are sea cucumbers, the one above is the ocellated sea cucumber while the one below is the sandfish sea cucumber (picture below).
Discovery Note:
The popular Chinese name for sea cucumber is haishen, which means, roughly, ginseng of the sea.
Being related to the sea stars, sea cucumbers have a soft, wormlike body and range from a few centimeters to 90 centimeters in length.
Unlike the sea star, however, they have no arms but use a cluster of tube-like feet around their mouth to gather food.
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.
The sandfish sea cucumber is the species of sea cucumber which people consume. But they contain toxins, so it must be properly prepared before consumption.

Now after finding a number of interesting things, it was time to look for the icon of the walk, the knobbly sea star. After some hard work from us, here is seventh 'discovery' (picture below).
Discovery Note:
1. They get their name from the knobs they have.
2. Although most of them are mostly red or orange in colour, beige or brown coloured knobbly sea stars have been spotted before also.
3. Can you believe that a knobbly seastar might be larger than your face? It’s about 30cm across! (look at the pictures below to get an idea)

After managing to find the icon, i decided to take a breather and take photos of the groups coming over to have their group photo taken with our icon. Here's ST and HK's group in the progress of taking the photo (picture below)
PY's group posing with the knobbly sea star (picture below)And of cos the beautiful sunset... (picture below)Finally, thanks to everyone for making this trip another wonderful and joyful one!

a) Dr. Yaacob Ibrahim, Minister for Environment and Water Resources, also participated with us for this trip. Read more about it at Nature Scouter's blog.
b) Also check out what did Nature Scouter aka SJ saw during the trip.
c) Read Tidechaser's experience of guiding Dr. Yaacob.
d) And of course Manta's experience.

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