06 August 2009

Nem surprise at Tanah Merah

I should know better than to underestimate a shore, but I never expected to encounter the Haeckel's anemone (Actinostephanus haeckeli) today!
And not just one, but two! The rest of the team saw another one as well!

Of course, whilst trying to photograph this large and rather intimidating anemone, a flatworm had to swim by in the fast flowing current. I had one shot at it, and it turned out to be Pseudobiceros uniarborensis. The first time I've seen one of these outside of the Southern shores.
"Twas a moonlit night and all was calm and quiet". Was my earlier cheesy intro before all this excitement. The last series of low tides during full moon was very quiet, so I was afraid we wouldn't see much.
Of course I was wrong!

This Ghost crab (Ocypode ceratophthalmus) seems to be snacking on the moult of a swimming crab. There were a lot of crab moults today. I actually photographed some 'crabs' and when I got home realised the eyes were clear. A very good indication that these are moults or empty crab skins. Oops.
Tanah Merah is generally a very fishy place. In the streams of water flowing out with the tide was this ball of rather largish Lined eeltail catfishes (Plotosus lineatus). Are they the same ones I saw the last time I was here? If so, they didn't seem to have grown much larger since.
I saw a lot flatheads (Family Platycephalidae) today! The Fringe-eyed flathead (Cymbacephalus nemathophthalmus), indeed has a fringe of golden 'eyelashes' over its eyes, and this one had colourful patterns on its body too.
But I saw more of these other flatheads without the elaborate 'eyelashes'. And I noticed today, they have patterned dorsal fins, as many of them had erected these fins.
I also saw several of these Brown sweetlips (Plectorrhinchus gibbosus). These fishes are often overlooked as they look and behave like drifting leaves.
In the streams and deeper pools were lots of little fishes and shrimps, often leaping out of the water every now and then. Perhaps to escape the night birds that I could hear out hunting on the shores? Abundant among the throngs of fishies were flashing bright blue tropical silversides (Atherinomorus duodecimalis), halfbeaks (Family Hemiramphidae), whitings (Family Silaginidae) and many more that moved about too quickly for me to get a good look at.

In the shallow pools left behind by the outgoing tide there were a gazillion Shadow gobies (Acentrogobius nebulosus). In all sizes from tiny ones to rather large ones about 10cm long. These fishes are not only tough and able to withstand heat and other poor conditions, they are also poisonous! No wonder there's so many of them.
Not all the small goby-like fishes were gobies though.
The little striped fish in the upper right corner is hardly bigger than the goby in the lower left corner. But a closer look reveals it is a very young grouper: the Chocolate hind (Cephalopholis boenak)! Indeed, sheltered shores like these provide places for young fishes to grow up into our favourite seafood.
A very special find by Chay Hoon was this pair of Estuarine seahorses (Hippocampus kuda) twined around an abandoned drinking straw.
The water they were in was getting low so we moved them to a deeper pool. Here's a closer look at both of them. The female seahorse usually has an anal fin. See the tiny little fin at the bottom of her belly?
The male seahorse usually lacks this anal fin and often his belly is bulging. Almost everyone seems to know that it is the papa seahorse that gets 'pregnant' with the babies. Is that why the males we see are usually brown or well camouflaged? While the females are often bright yellow?
I also came across a little Slender seamoth (Pegasus volitans) . This odd fish has a hard body covered by a bony skeleton of rigid plates. The tail is enclosed in bony rings. It has a long stiff pointed snout that is made up of modified nose bones. The small mouth is found under the snout.
The rest of the team shared on this blogs other marvellous fishes they saw such as scorpionfishes, a moray eel and lots of nudibranchs. I didn't see any slugs today.

I stayed mostly on the sandy places today, which are teeming with life! Showy and colourful animals, however, often distract from others that are less obvious.
I almost missed the little sand coloured goby near the big peacock anemone. And when I got home to process the photos, I noticed the little eyes of a buried Gong-gong snail (Strombus canarium) peeping out of the sand!
And some fishes were really well camouflaged, often bending their bodies and raising their fins and body parts so they appear quite unfish-like. On the left is a filefish (Family Monacanthidae) that looked like a bit of seaweed, while the rabbitfish (Family Siganidae) on the right has raised its dorsal fin so it looks positively prickly.
There was a patch with many large Common sea stars (Archaster typicus). This is the only shore on the mainland where we have seen these animals in such abundance. There were also many Cake sand dollars (Arachnoides placenta). They were all busy burrowing through the soft wet sand.
I saw one large Garlic bread sea cucumber (Holothurisa scabra) and Kok Sheng spotted another. There were also two of these large bobbly synaptid sea cucumbers (Family Synaptidae).
There were very many active Oval moon snails (Polinices mammatus) ploughing the wet sands today. And I finally managed to get a look at the body of this snail. It is usually very sensitive and will retract completely into its shell once it is touched. Its body is as pure white as its shell!
There were also very many of these Pink moon snails that I have yet to get identified. They are more obliging in showing their pretty body parts. I saw about ten of them in one small area.
The rest of the team also found this special Drill on the rocky area. It is probably Chicoreus torrefactus, Family Muricidae. A predator that lives on sandy areas near reefs, it feeds on bivalves drilling a neat hole through the shell. I haven't seen this snail often, so I have yet to start a fact sheet on it. We see new things all the time!
Since we are just coming out of the Anemone Hunts, it seems proper to look out for and document the anemones seen here. Alas, besides the spectacular Haekel's anemone I only saw one Moustached anemone (a tiny anemone that has yet to be identified) and one Haddon's carpet anemone (Stidhodactyla haddoni).
I didn't come across lush seagrass meadows, but there were some patches of small sparse Spoon seagrasses (Halophila ovalis). There was a good variety of common seaweeds though, and those were growing nicely.

I had a few interesting encounters with barnacles today. Like this cluster of very vigorous barnacles on a living crab. It looks like a Mud crab (Scylla sp.) and if so, then this doesn't seem to be its proper habitat. Perhaps the crab was part of an "Animal Liberation" release? Usually only sick and weak crabs get infested with barnacles on their shells.
And I saw this tiny barnacle in a large living boulder-shaped Pore coral (Porites sp.). Small animals find safety among hard corals and among branching corals. But even a smooth boulder-shaped coral like this one provides homes for determined little beasts like the tiny barnacle.
Our shores are rich and amazing because animals live on animals live on animals. The mind-boggling variety continues to expand as far as we are willing to look! We only covered a small part of this vast shore today. Who knows what else is out there?!

It's certainly worth braving the clouds of vicious blood-sucking sand flies to visit this shore.

Tomorrow, another look at this shore. More itching ahead...sigh.

Other posts about this trip