Friday, June 6, 2008

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:
Horseshoe crabs have known to 'roam' the earth since days even before the dinosaurs was around, so scientists calls them 'living fossils'.
Although they are called horseshoe crabs, they are not related to crabs. They are actually more related to spiders and scorpions.
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)
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.

The blood of the horseshoe crab is blue, as it is copper-based.
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:
Flatworms are hermaphrodite, which means a flatworm has both the male and female sex organs.
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! =)

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