Sunday, July 31, 2011

Back to the Great Reef: Terumbu Raya

What a GREAT way to start a GREAT day at the GREAT reef, Terumbu Raya!

Raya means great in malay. Terumbu Raya is a submerged reef off Pulau Semakau and it never fails to amaze me. This is my third trip here.

Just within a minute after the safe landing with the help of the ever skilful Jumari, I found this pretty Purple-spotted yellow flatworm (Pseudoceros laingensis)! It is only my second time seeing it, the first was at Semakau.

Another flatworm spotted during the trip will be this Blue-lined flatworm (Pseudoceros sp.).

Also found just moments after landing will be this tiny juvenile Kite butterflyfish (Parachaetodon ocellatus) poking around in the tide pool.

Near the reef edge, I stumbled across yet another charismatic fish. This is the Longhorn cowfish (Lactoria cornuta).

Another yellow fish but a very special one as well is this Spotted-tail frogfish (Lophiocharon trisignatus)! It is quite small, thus of course Chay Hoon was the one who found it. It looks less green than the usual ones that we have seen.

The reason why we saw more fishes on today's trip than our previous Raya trips is because this is our first time surveying this shore before sunrise.

In addition to fishes, there are also a couple of these Pencil squids (Family Loliginidae) which may be in the process of hunting down smaller animals for food.
There is a good variety of hard corals on this reef. I especially like the corals found along the stretch facing Pulau Semakau. One of the uncommon hard corals encountered would be the Moon coral (Diploastrea heliopora).

I hardly see the tentacles of the moon corals extended outwards from the corallites even though they are known to do so at night. I was pleasantly surprised to see some tentacles slightly coming out from a few corallites of this colony. It is not very obvious from this photo though.

It was nice to come across this huge colony of Lettuce coral (Pavona sp.)! What are the white rounded structures among the corals?

Here is a closer look at the rounded structures. I believe they are eggs sacs of cuttlefishes.

Here is a colony of the Carnation coral (Pectinia sp.) with the long tentacles extended outwards as well (not very obvious in this photo too). It is my first time seeing their tentacles.

The tentacles of this brightly coloured Favid hard coral (Family Faviidae) are fully exposed when submerged in water as compared to the top part.

It's great to spot the tentacles of the different hard corals during this morning's trip. Hard corals can use their tentacles to trap supsended food particles in the seawater to feed themselves.

This small colony of hard coral is a mystery to me. I have not seen it before do not know its identity. Is it some kind of a Cave coral (Tubastrea sp.)?

Terumbu Raya is known to have many sea anemones such as this Bulb-tentacled sea anemone (Entacmaea quadricolor). I came across several of them today and some of which are homes for Tomato anemonefishes (Amphiprion frenatus).

Russel shared with me his find of the Fire's anemone (Actinodendron sp.) which is probably quite common on Terumbu Raya.

I also spotted this lone Swimming anemone (Boloceroides mcmurrichi) near the reef edge. Usually these anemones are found near seagrasses.

This large snail is a Noble volute (Cymbiola nobilis) and it can be commonly found in most of our northern shores and some of our southern shores.

These snails were previously abundant in Singapore but is now considered vulnerable due to habitat degradation and overcollection for food and for its attractive shell.

This wavy shell belong to a living Scallop (Family Pectinidae)! It immediately shut its two valves / shells when I drew closer.

Another bivalve of a larger species will be the Fluted giant clam (Tridacna squamosa). Unfortunately, I only have bad news to share. Mei Lin's tagged fluted giant clam has died with only the two shells left beside the marker. :X

Slugs! It's always a joy to spot them on shore trips. This purplish nudibranch is the Black phyllid nudibranch (Phyllidiella nigra).

Ria found this large Polka-dot nudibranch (Jorunna funebris) with many well developed spots. Indeed this slug is a beauty.

One of the top finds of the day will be yet also another of Ria's find! This is probably a Flabellina sp. that looks similar to one of Chay Hoon's previous sighting at Sisters Island but are different in terms of their features.

It's truly fascinating to hear from Ria that she found this on top of a Garlic bread sea cucumber (Holothuria scabra)! Probably hitch-hiking in process. We have never seen this slug before.

All along, we thought that there was only one nudibranch until I reached home and realized another similar-looking slug of a much smaller size was photographed as well! Can you spot it at the bottom right hand side of this photo?

Here is a closer look at the colour pattern and arrangements of the cerata of this gorgeous nudibranch.

Last but not least, we will end this blog post with some crabby finds. I like this photo of the Swimming crabs (Thalamita sp.) with blue and green branching sponges and also a Stonefish sea cucumber (Actinopyga lecanora).

Near the reef edge, I found this rather huge crab found half hidden in a deep crevice. This was the only decent photograph that I have taken and am not sure of its identity. Ron has later shared with me that this is a Sawedged spooner (Etisus utilis) which I have seen at Semakau before.

Once again, Ria has found yet another wonderful find, this time an unknown crab that we have not seen before too. The striples near the edge of the carapace does make this crab look like a chicken pie or curry puff. Probably also because we were too hungry on the shores?! Haha.

Ron has commented that this is the Granulated Flatfoot (Platypodia granulosa). It is probably the second most poisonous crab in Singapore. Thanks for the id!

This rather docile and gentle crab has pretty brown claws and some nodular bumps on its body.

It's incredible to find new sightings on our reefs despite having visited some many of our shores several times!


Ron Yeo said...

the big crab is a sawedged spooner (Etisus utilis), while the last one is the Granulated Flatfoot (Platypodia granulosa) - believed to be the second most poisonous crab in Singapore.

Kok Sheng said...

Thanks for the ids, Ron!

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