Thursday, June 5, 2008

Zoanthids hunt at Hantu

This morning the zoanthids team accompanied zoanthids expert, Dr James Reimer to Pulau Hantu to check out the zoanthids there. Basically, zoanthids are like colonial anemones with tiny tentacles on a tiny oral disk supported by a tiny body column. We don't really know them so it's really great to have Dr James with us.

We were told that some zoanthids contain powerful toxins where minute quantities of palytoxine within zoanthids can paralyse or kill predators.

This is called Palythoa tuberculosa and they can form mats in the reef.

They can incorporate sand into their bodies so if you are brave enough touch it, it can be rough. Somehow, this one has sand on top of the zoanthids.

And this is what is meant by forming a rubbery mat. Look at the scale of the zoanthid colony as compared to the ape-y Vyna. :-)

There are other types of zoanthids that are more colourful.

These are Zoanthus sansibaricus. Unlike Palythoa tuberculosa, this one generally don't incorporate sand in their bodies so if you touch it, its smooth feeling.

The zoanthids here are Palythoa mutuki.

Also noted are zoanthids with a pink and and green centre and a black stripe. They say the pink is a hello kitty pink =_=

I was too sleepy to note what is it though. But nevertheless, we have learnt a great deal from Dr James today. He really shared a lot of interesting stuffs along the way and indeed is a very nice guy.

To know more about zoanthids, Ria has done a great post on them, check out her post from yesterday's Kusu zoanthids trip. She will also post more of today's findings soon.

Along the zoanthids hunt, we also saw a lot of other marine creatures.

Been some time since I've seen Acropora corals and they only can be found at good reef conditions.

This Acropora coral has tentacles out which I've not seen before.

Look at the tentacles coming out from the polyps, wow!

During low tide, this mushroom coral was exposed.

Soon, we realized we were surrounded with really a lot of mushroom corals!

I'm still not so pro at hard coral identification. I think this is a Merulina species.

Is this hard coral a Pachyseris species? Anyway, they are rarely seen, so Hantu really is a good place to find these rarer corals.

Yuchen found this bulb-tentacled anemone which I can't see any resident tomato clownfish though.

Beside rocks with zoanthids also include this stonefish sea cucumber.

There are a number of barrel sponges that look stunning.

But there is this one with wormy stuffs on it. Hmm, wonder what is it.

At another less visited lagoon, there are quite a number of these ascidians that look pink and white.

There are also a number of octopus in this very rich reef. Glad no stonefish encounter today for any of us though.

This filefish was trapped on dry land so we tucked it back into the water.

Yuchen found this Denison's nudibranch that is bigger than the usual smaller ones.

Yuchen is indeed a great hunter seeker as he also found this seahorse mama.

As well as this pregnant sea horse papa nearby. Wow, look at the stomach size!

Somehow, today is also a crinoid day, with many different types of feather stars encountered. Enjoy looking at the six different colours/patterns I've posted below :-)

Here is part of the team checking out the other part less visited. And to our surprise, there are also a lot of zoanthids.

It was a good morning out at Hantu today. On the way back, I saw this signboard on one of the patch reefs. First time seeing this danger signboard, looks interesting.


juanicths said...
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juanicths said...

Dearie, I don't think that's a Neptune's cup sponge. It looks more like the barrel sponge (likely Xestospongia testudinaria) we see both intertidally and subtidally. It's a common mis-ID that we have been doing. Have cut-n-pasted an email that Swee Cheng sent to us in Nov last year, enlightening us about this.


"Hi xxxxx,

Found a photo of a sponge that is labelled "Neptune's cup sponge" at the link below.

It looks like a Xestospongia testudinaria, or what many people commonly referred to as "barrel sponge" from the maroon red colouration. The Neptune's cup sponge is reported to be pale yellow in colour.

The Neptune's cup sponge, Poterion patera (Hardwicke, 1822) is the first sponge described from Singapore, in 1822, 185 years ago. The title of the paper is "Description of a Zoophyte, commonly found about the Coasts of
Singapore Island". Haha... It was commonly found here! The sponge had a shape of a cup or wine glass, 37 inches in height and 17 inches in diameter. I have seen specimens more than 1m in height and 60cm in diameter in the Amsterdam Zoological Museum.

It was very popular with the British and the Dutch who collected numerous specimens from Singapore, Sumatra and Java. Several specimens can still be found in the British Natural History Museum, Naturalis Museum and Zoologisch Museum Amsterdam. However the enigmatic sponge might be extinct according to Dr. Rob van Soest, the editor of Systema Porifera, who has also worked extensively in Indonesia to be extinct as the last record of this sponge was in 1908. There were several major expeditions and surveys in Indo-Malayan since 1908 but none was sighted.

It will be great if we can find this sponge in Singapore. Hope you can help to keep a look out for this sponge when you are diving in Singapore water and pass this information to fellow divers who might be interested to help. If you think you have found the sponge, please cut a 2cm cube fragment, put
it in a plastic bag and freeze it as soon as possible. This will allow me to make a skeleton section and spicule preparation essential for identifiying the sponge. Thank you very much.

You can find see photos of the Neptune's cup sponge dried specimen, the Hardwicke, 1822 paper, and figures of the different form of the sponge specimen at the link below.

Hope these information are useful for the search of the sponge. Please let me know if you have any questions.

Swee Cheng"

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