Horseshoe Crab Research and Rescue

Source: "A Guide to Mangroves of Singapore", Peter K. L. Ng and N. Sivasothi (editors)

Previous related posts:
http://grasstales.blogspot.com/2009/06/rmbr.html
http://grasstales.blogspot.com/2009/04/coney-island-horseshoe-crab.html

Directions to the nameless track...
1. Take mrt to Kranji MRT station.
2. Take bus 925 from station.
3. Alight at the Chinese Temple.
4. Cross the road to the nameless track.

I am surprised we did not get lost, because it is indeed a god-forsaken place haha.

Anyway a year ago, I was at this Kranji MRT station too, and I was puzzled over the spaciousness of the station.  Only today did I realise the Turf Club is just beside the station.  Oops.

As we reached the nameless track, we happened to double check our location with some people and they decided to show us their pot of Mangrove horseshoe crab (Carcinoscorpius rotundicauda) and that these are on the verge of being slaughtered for food.  It does not look like a crab so how do one eat HSC?

The uncle went on to show us where to cut open the body and eat the unlaid eggs directly after cooking.  I would advise none of you to try because it is said that HSC are toxic.  And besides you are only eating the eggs and throwing the rest of the HSC away which I feel is a waste.  It is like eating shark's fin and throwing away the shark.  SAD!

After a brief chat with them, we headed down to report to the i/c. She went on to give us a brief introduction of this "living fossil" which still looks almost similar to the fossils 400 millions years old. Then we begin our rescue mission (and mini shore clean-up session).

A total of 168 (think that should be the figure) HSC was found. I was told these HSC had to be measured and the males and females counted. But I'm curious to know what happens to the tiny HSC? Are they also measured? And since they are too young to do a gender identification, what were they classified as?

Which brings me to the objective of this mission: to keep track of these HSC from what I gather. Which is why they will search for them, figure out ways to tag them, then search for them again the next month (depending on the tidal conditions though) and analyse them.

But why is HSC so important? Well it is a known fact that their blue, copper-based blood called lysate is important in the biomedical world as a purified version can help detect baterial toxins, important in disease detection as well as ensuring the cleanliness of equipment.

To identify if it is a female HSC, notice the first 2 pairs of legs. For the females, all the pairs of legs are similar.

For a male HSC, the first 2 pairs of legs are like bulbous front pincers which they need to cling onto the females whilst mating.

Barnacles on the HSC. They are encrusters, attaching themselves permanently to a hard substrate.

Which leads me to my next question. As the HSC moults to become 25% bigger, what happens to the barnacles on the original shell? I asked the researcher but it seems that not much studies have been done on it. He mentioned that usually the moult does seems pretty smooth so he is not sure is it the barnacles dropped off and move to the living HSC or that this HSC happened to not have much barnacles. Hmm, sometimes one can really have 1001 questions for Mother Nature but how much she wants to reveal would probably depends on her mood.

The underside of the moult sometimes deceives me into thinking this is a living HSC.

And this is the opening which the HSC will crawl out then hide in some discrete area to be suntanned as it is usually soft after moulting. Note that we are not very certain is it the sun, the water, the existence of both elements or other elements but gradually the HSC shell will become harder and soon it will behave like the typical HSC.

The area we were walking was soft mud and it was indeed tough walking. At one time, my feet were stuck that I had to twist my way out, but I twisted too hard and spewed mud at my friend. Horror! Felt so guilty to her the rest of the day as neither of us had brought spare clothes.

And judging the muddy trails, you can expect how muddy our booties are... Eeeks haha!

Would I go back again? Actually I might although I don't really like walking on the soft mud... and am lazy to bring extra clothings still... Let me think about it till the next time...