Tuesday, June 2, 2009

Semakau Inter-Tidal walk on 31st May 2009

Ninety Fifth Discovery Posting

A late posting (again). Got to blog faster next time.

Anyway, just the past Sunday, 31st May, leading a group of puffer fishes (the name for my group of participants), we visited the inter-tidal area of Semakau.

Despite the hot and scorching weather, we still manage to see a number of organisms, and our first 'discovery' of our walk is this juvenile mangrove horseshoe crab (picture below).
Discovery Note:
1. I forgot to mention to the puffer fishes that horseshoe crabs are actually not crabs. They are more related to spiders and scorpions.
2. They are really ancient creatures as they have been around even before the age of the dinos. Wow.
3. Although horseshoe crabs have exoskeletons like crabs, the make up is different. The exoskeleton of a horseshoe crab does not include calcium but is made up of chitin and protein.
4. Their tails looks dangerous but they are not. Their tails are not used to sting people but used to help turn themselves upright if they are upside down.
5. Their blood used to be harvest as their blood contain a substance which can be used to test the presence of bacteria in human medication and medical tests. However, a team from NUS has managed to reproduce this substance in the labs without using horseshoe crab's blood.
6. Read more about horseshoe crabs @ http://www.wildsingapore.com/wildfacts/arthropoda/limulidae/limulidae.htm.

As the puffer fishes 'swam' across the seagrass meadows, I got them to stop halfway and pose for two group photos (pictures below). After crossing probably the biggest seagrass meadow in Singapore, a colony of common sea stars were there to greet our arrival. Here's one of them and our second 'discovery' (picture below). Discovery Note:
1. It has an interesting way of eating. Instead of putting food into their mouths like us, common sea stars stick or push out their stomach, greenish in colour, which is located on their underside to eat.
2. If possible, leave the sea stars in sea water. This is because like we need blood in our bodies, they need sea water in their bodies to look and be healthy.
3. Read more about them @ http://www.wildsingapore.com/wildfacts/echinodermata/asteroidea/archaster.htm.

The third 'discovery' is another species of sea star. The knobbly sea star (picture below)!Discovery Note:
1. They used to be found in huge numbers before our shores were developed. Nowadays, sightings of them are limited to only a handful of shores.
2. They can come in different colours, but colours usually range in shades of orange, red, biege.
3. Read more about them @ http://www.wildsingapore.com/wildfacts/echinodermata/asteroidea/protoreaster.htm.

And of course, we would not miss a group photo with the 'star' of our walk (picture below). Like previous months, we came across a number of noble volute which were laying eggs or close to their egg mass (picture below). Fourth 'discovery'.
Discovery Note:
1. As you can see, the shell of a noble volute can be really pretty. So people collect them.
2. They are also collected for food. Combined with the loss of habitats, they have labelled as 'vulnerable' in the Red List of Threaten Animals of Singapore.
3. Read more about them @ http://www.wildsingapore.com/wildfacts/mollusca/gastropoda/volutidae/nobilis.htm.

As the weather was really hot and humid, a lot of organism hid or burrowed themselves. So to spot more things, we looked into more tidal pools than usual. And in a number of them, we spotted fan worms. Here's one of them and the fifth 'discovery' (picture below). Discovery Note:
1. They might look like plants to some. But they are actually segmented worms, think earthworms.
2. The fan-like thing sticking out is actually the worm's head. The feathery-like things are modified tentacles called radioles.
3. These radioles help the fan worm to gather food. Food is any tiny food particies found in the water.
4. Read more about fan worms @ http://www.wildsingapore.com/wildfacts/worm/polychaeta/sabellidae.htm.

In other tidal pools, we also spotted the very beautiful red maiden's fan (picture below).
Discovery Note:
1. Another object which looks like a plant. But this is actually an animal.
2. To be more specific, this is a kind of sponge.

Our hunter seekers also manage to find this really interesting 6 armed knobbly sea star (picture below).
And also 2 juvenile cushion sea stars! Sixth 'discovery' (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.

Before i end, I would like to thank all puffer fishes for making this another fun trip out despite the heat. =D

a) Tidechaser's posting: http://tidechaser.blogspot.com/2009/05/filming-at-semakau.html
b) Manta's posting: http://mantamola.blogspot.com/2009/05/semakau-inter-tidal-walk-31-may-09.html
c) Urban forest's posting: http://uforest.blogspot.com/2009/05/semakau.html

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