Tuesday, March 2, 2010

Semakau over the last weekend of Feb

111th Discovery Posting

It has been a mini hiatus from blogging recently and now I'm back!

On this recently passed weekend, I visited Semakau twice for two different reasons. Both were for Project Semakau, however the Saturday trip was for a transect monitoring session while the Sunday trip was for a guided trip for schools where I was to be a hunter seeker.

This entry is a summary of some of the things which I found or saw.

First up is something which I managed to spot for 2 days in a row, the spider conch (pictures below). First 'discovery'.
Normally, it is quite hard to spot the spider conch as they are well camouflaged amongst the reefs or rubble area. Their camouflage can come from the algae growing on their shell and even sand which covers it. Once flipped over, you can see that its shell is actually really pretty. That is why people collect their shells and at the same time, people collect them for food. Additionally, places for them to live in are hard to come by in Singapore now due to development. So due to these reasons, they are now considered uncommon in our waters.

Another uncommon marine organism in Singapore is the knobbly sea star. Semakau is one of the few places where one can find a significant number of them. Here are some of the knobbly sea stars I saw on Saturday (picture below). Second 'discovery'.
The knobbly sea star's name is as such because of the knobs present on its body. It is believed that these knobs deter predators from eating them. However, fishes like the puffer fish are known to eat them.

The knobbly sea star is also somehow one of the highlights of Semakau or any other inter-tidal walks. This is because they can grow up to about a width of 40cm wide, so they can be a 'BIG' star.

Beside the knobbly sea stars, you can also find cushion sea stars on Semakau. Here are some juveniles (picture below). Third 'discovery'.
Here's a 'adult' sized cushion star (picture below).It's always a joy to see a big cushion star as they are more commonly seen by divers in deeper waters. For the juveniles, they probably like to hide in the seagrass area before moving deeper into the reefs once they are of the right size/'age'. They have been reported to feed on organic particles found in the sediments, immobile animals and even on corals.

And of course, not to forget the common sea star (picture below). Fourth 'discovery'.All sea stars (which I know) has a water vascular system. This is like our blood circulatory system where blood is pumped all around our body. But instead of blood, the sea stars pump sea water around their bodies. So it is best to handle the sea stars in sea water if you want to touch them.

The last thing I wish to write about is this nudibranch which I have never seen in Singapore. It's a Varicose phylid nudibranch (Phyllidia varicosa). Fifth 'discovery'.The phylid nudibranchs are said to be one of the most toxic nudibranchs. It is said that if they are stressed or feel endangered, they will release a toxic chemical into the waters near them. This toxic can kill a whole fish tank of fishes if ever released into one. So to be on the safe side, don't ever handle this nudi.

That's about warps up this posting. Thanks for reading and everyone who were on the trips on both days for making it another great weekend out.

1) KS's entry for the Sunday trip: http://wondercreation.blogspot.com/2010/02/two-new-nudi-sightings-for-me.html

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