Saturday, May 24, 2008

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:
'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.
Nudibranchs are related to snails. Little baby nudibranchs are born with shells, but they lose them when they become adults.
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:
Their tube feet are interesting as they are used for walking, handle food as well as breathing, talk about multi purpose!
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.
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:
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.

We also spotted this ocellated sea cucumber amongst a small patch of seagrass, fourth 'discovery' (picture below).
Discovery Note:
The popular Chinese name for sea cucumber is haishen, which means, roughly, ginseng of the sea.
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! =)

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! =)

1 comment:

alicepng said...

Hi July, Just read your write-up and found it to be very interesting. The pixs were good too. A wonderful recap of our walk. Yes, we're the Png family who had asked you to e-mail us some photos.
Would appreciate it if you can do so at your earliest convenience. Thanks so much! Really looking to doing more walks. Semakau was wonderful in that it was in the morning so really felt like a brand new day...although the boat journey was not really memorable and much too long...