Monday, August 20, 2007

Monitoring Carpet Anemones

Carpet anemones (Stichodactyla haddoni) were one of the most hit fauna in Chek Jawa during the mass death. Before the mortality event this January, CJ guides have to keep reminding the visitors to avoid the landmine full of carpet anemones on the sandbar. Now, there is almost none found on the stretch of sandbar in Chek Jawa.

Does that mean the Chek Jawa is dead???



Nope. Chek Jawa is recovering. What was surprising is that at the south west end of the wetland, next to the coral rubble, there are many and many of unimpacted adults doing very well, near to the seagrasses. And at the end of the seagrass lagoon and the sandbars, we can also see some new and adult carpet anemones, though they are much fewer there. What is exciting is that many baby haddons are coming back at the extreme edge of the north of Chek Jawa. They come in very small to bigger sizes.

The plan to monitor these guys is to mark and follow the growth of 25 individuals from the impacted area and then 5 older and healthier anemones from the south west end. The idea is to measure diameter of the disc and then count tentcles in 1 cm square areas to plot it over time as we continue to monitor in the future.


I was privileged to have Ria as the photographer of these 30 anemones marked for monitoring. Her camera takes really good and sharp photos and it makes counting of tentacles easier. She has also done a great job in labelling the photos, so I can concentrate more on counting the tentacles. After cropping each photo to focus on the 1 cm squares, it is about time to start counting 30 x 2 = 60 squares of tentacles.


How did I count them? Use MS paint to dot each tentacle after counting it so I won't lose count. And after a few, lethargy sets it, it is NOT easy!


Especially when there are more than 100 tentacles in the square. Thank God that Liana helped out a bit too, making the work more bearable. She wasn't as complaining as me though...Haha.

After more than half a day of effort, finally DoNE! :-)

(All photos taken by Ria Tan)

6 comments:

ria said...

WOW! I'm impressed by your dedication!

So how many tentacles does a carpet anemone have in total?

Perhaps we should guess, and the one that comes closest gets a prize?

The prize should be they get to come and do the NEXT carpet anemone monitoring! :-)

Or maybe that's not such an attractive prize...

Well, I'm glad it turned out OK. I wasn't sure if the tentacles were sharp enough. Especially for the Hungry Anemones that tried to eat your square things.

koksheng said...

Haha, whoever is game enough, feel free to guess how many tentacles does the carpet anemone (1st picture of this post) have.

Let's see who is the winner with the closest guess. It will be a mystery prize (simply because I have not came up with the prize yet). :)

ria said...

My guess is 642 tentacles!

koksheng said...

you will be surprised the answer is more than 10,000!

JC said...

Great effort and an interesting one I must say.

However, I seriously doubt the amount of testicles remains the same as the anemone grows.

btw, is haddoni the only species you found in CJ? Any gigantea or mertensii?

koksheng said...

Hi Jenn Chye, yes there is only haddoni in Chek Jawa. Dr Daphne and team didn't find any gigantea or mertensii though.