Saturday, 23 June 2007

commensal crazy in Kusu!!!

Was out doing our modified ReefCheck with ReefFriends today, and I must say, this was one of my most fruitful dives at Kusu!! As expected, was relegated to doing LIT with coral genera ID for the deeper transects along with MS. Sadly, when compared to Semakau, the reef slope here hardly has any live coral cover. It made our work a little easier since we could finish the LIT with relative ease and look for stuff to photograph. =^-^=

Haven't really had to explore Kusu underwater recently, so it was really a pleasant surprise to see all these sea fans and whip corals all over the place. Even more amazing were the number of crinoids EVERYWHERE!! Poor HB had to count/estimate the number of crinoids for the mobile invertebrates survey.....


Then there were the HUGE seafans that were sticking out of the slope. I narrowly missed swimming right into one when reeling back the tapes... *phew* That would have been one BIG guilt trip for me man!!

And this was the first time that I have seen SO many brittle stars curled around whip corals. All those little bumps on this whip Gorgonians aren't some kind of disease. They're all little brittle stars!!


BUT, the dive was not just filled with enormous Gorgonians, the REAL highlights of the dives were the macrolife =^-^= Namely, whip gobies, gorgonian shrimps and allied cowries that live commensally on seafans and whip corals. These creatures have absolutely amazing camouflage, and generally, it would be near to spot them if you were just swimming past and they keep incredibly still. Rather difficult subjects to photograph using a point-and-shoot since they are skitterish on top of being tiny and well camouflaged. The first of the many that were pointed out was a pair of sawtooth Gorgonian shrimp (Tozeuma armatum). This fella was probably the largest (or rather, longest) of all the commensals we saw.

Then there were all these tiny tiny shrimp scurrying all around. I only have nudibranch and fish books to help me in ID-ing photos, so will need a little help here in getting these guys ID-ed. Any suggestions would be more than welcome! ^^


Contraty to what I intially thought, it seems like whip gobies are rather common in Singapore. First spotted (and tried to photograph them) during the RF survey trip to Semakau last month. Managed to get a somewhat blurry shot of THREE of them on a single whip coral. And today I actually managed to get a better shot of one when I was in search of more allied shrimps!! *yay*

And then there was another one that was camera shy but seemed to like playing peek-a-boo at the same time. See him/her?


Didn't spot as many allied cowries but here was one really pretty one that MS pointed out. This one's a spindle cowrie.

Sure looks different from the usual roundish cowries that most people know of. Allied cowries (aka egg shells) are closely related to cowries, and they DO belong to the same superfamily. What does this mean to all those non-biologists? Simply put, allied cowries and cowries are kinda like cousins. Unlike their cowrie relatives, these small allied cowries are masters of disguise! They have adapted to look like what they eat (yes, they feed on softcorals and Gorgonians), and there are even some that have polyp-like extensions that resemble the feeding polyps of their host soft corals!!

But soft corals aren't the only ones with their little creatures living on them. Hard corals do too!! Like this coral shrimp (Vir philippinensis) that's living among the bubble-like tentacles of this bubble coral (Plerogyra).


The main reason why I saw as many as I did is my buddy, MS, who is simply AMAZING!!! How he can spot all those little critters on the whip corals and sea fans is really beyond me. Really thankful for his eagle-eyes. woceht has also benefited from his sharp eyes, and they saw wonderful macrolife at Hantu in April as well!! Click here for woceht's account on the experience. ^^

Of course, no dive in Singapore would be complete without nudibranchs!! The Phyllids were just EVERYWHERE on the reef and there were also a couple of blue dragons (Pteraeolidia iathina) out posing for me.

This particular phyllid even looked like it was winking at me with one rhinophore (those stubby stalky looking things) up and the other retracted. ^^


And things just keep getting better!! Wonder what MS is so intently photographing in that hole..

LOBSTER!!! Poor guy was probably freaked out by us swimming up and down and flashing at him while taking photos... Not too sure which rock lobster it is but *think* it may be a painted rock lobster...


Here are also a coupld of interesting things that I simply can't figure out... Anybody know what these are?
(1) Funny looking blobby thing at the tip of the whip coral

Update: possible ID with Nigel's help
Seems like this rather funky looking thing may be a Tubularian, and is actually a kinda of hydroid!!! So hydroids DO come in all shapes and sizes, including some that deposit a calcium carbonate skeleton (i.e. Millepora aka CME that LIT-ers should be familiar with). The very clear close-ups on the following sites do seem to confirm that this is a Tubularian hydroid. Interesting that one of the species is actually "common throughout the British isles". Perhaps this is yet another proof of Singapore's colonisation by the British!! They even brought it along with them to SEA? *okies, am starting to crap here*
New Jersey Scuba Diver
Tubularia larynx
Marine Biological Laboratory, Woods Hole

(2) Anemone-ish looking thing


Yep, we definitely went home a happy troop of people!!

3 comments:

Anonymous said...

Hi Juan Hui,

Great that people are noticing the gorgonians, and also the cool organisms that are associated with them.

The "funny looking blobbything at the tip of the whip coral" is most probably a species of Tubularia.

It was reported (together with other associates of Singapore gorgonians) quite some time back (mid-late 1990s). I can give the references to the publications if anyone is interested. Contact me at nigel_goh@nparks.gov.sg.

Nigel

MS said...

you over-flattered me! i guess the fact that i didn't eat prawn when i was young helps.. they like me!

juanhui said...

no need to be humble, you with the magnifying glass attached to your eyes!! hmmm... maybe I shld stop eating prawns too ^^