30 August 2011

Cyrene: mainly molluscs with shark!

We met many molluscs on Cyrene this morning. Including the delightful China moon snail!
Also many tiny echinoderm babies, and Ivan finds a shark! Sadly, massive flaring still ongoing at Jurong Island.

Some of the moon snails were 'carrying' little snails on the back of the foot! I saw two carrying Button snail shells! But we couldn't find any live Button snails! This is the first time I've seen so many China moon snails (Natica onca) out and about. First spotted by Mei Lin last year, so far, I've only seen them on Cyrene. They are very pretty with a decorative shell and gaudy foot. The operculum (door that closes the shell opening) is white and shelly with grooves.
We also came across a swarm of Grey bonnet snails (Phalium glaucum)! They were busy feeding on the many large Cake sand dollars (Arachnoides placenta) found on the clean sand bars here.
When I first saw this one, it was half buried with its siphon sticking out of the sand like a snorkel. When I gently took it out, I realised it was stuck to a sand dollar. Here's a look at the underside of these snails, and their very large fat foot! Chay Hoon and Mei Lin also found the Japanese bonnet snail (Semicassis bisulcatum). So far, I've only commonly seen these two snails also at Changi. In many ways, Cyrene is like the Chek Jawa of the South with many animals found here that are only usually found on our Northern shores.
Kok Sheng found this Egg-white moon snail (Polinices albumen) with its broad white body expanded. It's another snail that I've only also seen at Changi.
Just as we were leaving I saw these enormous olive snails next to one another buried in the sand. I think they are Olivia miniacea and so far, I've only seen them on Cyrene.
Today I had some luck with nudibranchs. Saw this black beauty, I'm not sure what it is exactly.
Another nudibranch I found was this Discodoris lilacina which I've so far only seen on Chek Jawa and Pulau Sekudu. Chay Hoon and the rest of the team found lots more nudibranchs! Kok Sheng saw a lot of Forskal's sidegill slugs (Pleurobranchus forskali) too!
I came across several Starry flatworms (Pseudobiceros stellae), and I think the one in the lower row is also a Starry flatworm although it looks rather different.
Today, I came across many baby echinoderms! For the first time, I saw many small Common sea stars (Archaster typicus). They were very much smaller than the usual ones we see.
Here's a closer look at the smallest one I saw, which was about 3cm in diameter.
There were also lots and lots of White sea urchins (Salmacis sp) which are common in the North but not often seen on our Southern shores. On Cyrene, these come in various shades of white, with spines that might be white, greenish or pinkish.
I also came across many tiny White sea urchins!
There was also a young Long-spined black sea urchin (Diadema sp.), its spines are still banded.
James found a nice little heart urchin (Lovenia elongata)! These animals are efficient burrowers (as demonstrated by this animal as we tried to photograph it) and usually seldom encountered above ground.
The rest of the team showed me the Pentaceraster sea star (Pentaceraster mammilatus). It's a young one and seems to be doing fine. We also came across a large Remarkable sea cucumber (Holothuria notabilis) buried in the sand and I saw some small Garlic bread sea cucumbers (Holothuria scabra) in the seagrasses and several Long black sea cucumbers (Holothuria leucospilota) in the rubbly area.
I also saw this odd looking Swimming anemone (Boloceroides mcmurrichi). When I gently waved it off its perch, it shed its tentacles and it did swim. But it was pinkish with spots! Quite different from the Swimming anemones I usually see, which have banded tentacles.
There were lots and lots of tiny swimmin anemones everywhere this morning. Many were stuck on the seagrass blades. Some of them were swimming! I also saw some Haddon's carpet anemone (Stichodactyla haddoni) and two Snaky sea anemones (Macrodactyla doreensis). I saw a tiny Giant carpet anemone (Stichodactyla gigantea) and it was constantly moving its tiny tentacles, a distinctive feature of this anemone!
I also took the opportunity to get better close up photos of some of the special seagrasses seen on Cyrene.
Needle seagrass (Halodule sp.) can be very broad or very narrow. But they have the same 'bat-ear' tips!
Here's a closer look at the leaf tips of Sickle seagrass (Thalassia hemprichi) and Serrated ribbon seagrass (Cymodocea serrulata).
There are many different kinds of seaweeds on Cyrene, but I didn't really look at them today. I did notice that this patch Oval sea grapes (Caulerpa racemosa) had some paler portions surrounded by a greenish 'haze'. Is this seaweed 'spawning'? So much more to learn about our shores!
Cyrene is much too big to check out thoroughly in one trip. I'll have a closer look at the seagrasses when TeamSeagrass makes its next monitoring trip to Cyrene. I didn't have a chance to see the reefs today.

There are still many many Knobbly sea stars (Protoreaster nodosus) on Cyrene, both small and large.
But alas, I came across this Knobbly sea star that was rotting away. It smelt very bad and on the upper side was it was fragmenting with its 'knobs' falling off.
Here's a closer look at the upperside of the sea star and its underside. I don't know why it is dying so dramatically.
We arrived well before dawn, but we didn't need to use our torches for the landing. The area was lit up by the massive flaring on Jurong Island. Apparently dubbed the Eye of Sauron by some. The height of the flame seems almost as tall as the chimney!
In comparison, the flaring on Pulau Bukom seems mild.
In daylight, I realise the big thing in front of the flaring is the dredger. Dredging near Cyrene has been extended multiple times and as of now scheduled to go on until October. These are some of the pressures on Cyrene as it lies in the middle of the industrial triangle.
I wasn't really looking for fishes and accidentally came across a little Slender lined shrimp goby (Cryptocentrus leptocephalus), apparently my first sighting of this fish on Cyrene. Hurray!
But the most amazing fish seen was by Ivan who spotted a large shark trapped in some fish traps left on the shore! Of course Ivan released the poor beast and dealt with the traps. It seems traps are starting to be laid on Cyrene again. We need to constantly keep an eye on this special shore!

More about Cyrene.

Posts by others on this trip
  • Mei Lin with strange fishes, lots more tiny snails and slugs.
  • James with MORE slugs, tiny fishes, tiny crabs and other amazing life!
  • Kok Sheng with slugs, stars, fishes and more!

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