A great start to 2010 at Pulau Semakau!

The first exploratory walk on 2 Jan 09 marked a fantastic start to the year at Pulau Semakau. Despite a rain cloud that seemed to follow our boat in heading towards Semakau, we enjoyed great weather throughout the walk. Not only so, it was a self-declared Sea Cucumber day, because there were not one, but THREE new records/ first sighting of them at Semakau! LK also successfully located her rare plants. In summary, everyone was simply overjoyed!

While some of the RMBR guides explored the usual area where we conduct our walks, I followed a few others to the extreme left side of the intertidal area, near the southern point. Hmm.. what were the guys looking at?

The Hell's Fire Anemone (Actinodendron sp.) ! There were quite a few of them in this area. The HSBC volunteers had conducted a transect at this column before, but I don't recall seeing so many of them, then. This anemone like all others, have stinging tentacles, except that it's sting is probably much more painful, to be worthy of its name. A clear distinction of this anemone is the white stripes radiating from the anemone's mouth, as well as the distinct trigular-shaped branches.

Did you think that this is a snake at first glance? Nope, this is not a snake nor a worm, but the Synaptid Sea Cucumber (Family Synaptidae). This is the longest Sea Cucumber that can grow up to 3m long! It has feathery tentacles at one end that lashes in water to feed on the detritus. Their body wall is very thin, thus very delicate so its important that we do not handle them. Instead of tube feet, they have hooked spicules to stick to things just like how the velcro works.

Although we have been seeing these Sand-sifting Sea Stars (Archaster typicus) on almost every trip, I needed to remind myself not to take them for granted. They are still vulnerable to the rapid loss of habitat or the sudden influx of freshwater like the rest of the marine life. Deriving their name from their ability to sift and burrow into sand, they actually are 'heartless' and 'brainless'!

I have a sudden affinity with Turban Shells recently, even when I wasn't looking out for them. This is likely a Turbo intercostalis since it has a smooth trapdoor which is its operculum that can completely seal the entrance of the shell. This dome-shaped door protects the occupant from unwanted guests, and looks quite like a cat's eye!

I didn't see as many Tube Anemones (Order Ceriantharia) as I did at Chek Jawa 2 weeks back. The Tube Anemone lives in a tube made up of mucus and sand, thus its name.

July spotted 2 photogenic Bigfin Reef Squids (Sepioteuthis sp.) who were very cooperative in posing for us. Interestingly, Squids are not fishes, but are molluscs and are relatives of clams and snails but do not have a heavy outer shells. They have lightweight internal skeletons and can zoom off by jet repulsion. They are actually not so blur and 'sotong' and can change their colour to communicate with each other or hide from predators. When alarmed, they may go to the extreme of squirting a cloud of 'ink' which contain substances that affect the senses of other marine animals. The clouded water also allows it to make a getaway. This is just like smoke bombs that humans use, perhaps its inspired by the Squids!

Wish answered and fulfilled! I was really hoping to see the Knobbly Sea Star (Protoreaster nodosus)before we started the walk, since I never seem to have any luck with them. Although I only saw 3, it was heartening to hear that July saw 25 of them! (see what I mean about my lack of affinity with them?). Named after the distinct knobs on their body, this species is actually endangered on our shores largely due to the loss of habitat, and in other countries to the aquarium trade. Even on Semakau, if we do not conserve their habitat by perhaps having a marine park, I wonder how long will the population persists.

I caught sight of the Hairy Crab (Pilumnus vespertilio) moving as fast as it could (although still relatively slower as compare to its swimming crab relative). While it cant' quite compete in the speed arena, it is a champion in camouflaging especially underwater when its hairs causes it to puff up and breaks its outline. On land, it blends into the surroundings too!

Speaking of the devil, 2 Swimming Crabs (Portunus pelagicus) were hiding discreetly in the seagrass meadow. The female was about to moult, and the male crab was waiting faithfully and patiently behind it, preparing for procreation.

While its not distinguished in this photo, the Noble Volute (Cymbiola nobilis) has a really pretty shell, in addition to its bright and colourful foot. Although a fierce predator that suffocates its prey with its strong foot, the Volute is often overcollected for its shell, and as food too. Nonetheless, we have been sighting egg-laying Volutes, like this one, and this is clearly a good indicator of the good health of our shores - that is if we continue to keep it this way.

It was mission accomplished when July spotted the first Galloping Sand Star (Stellaster equestris) of the day. Just last month, this star was a first record for Semakau! Marcus spotted the second one, but both seems to be in bad shape, looking fairly pale. The second we saw actually had 2 injured arms. These stars are more easily identified by its underside which has dots/ dark pigments near its mouth. Not called the Galloping Sand Star for nothing, this star can actually move by leaping or jerking. Really hope that they can nurse back their health, and we can witness them in action on our future trips.

First-records-on-Semkau galore! This was certainly beyond expectation but we are all not complaining! The first new record was the Ball Sea Cucumber (Phyllophorus sp.) that Ron found. This sea cucumber is usually buried in sandy areas, showing only their branching feeding tentacles lashing in the water for detritus.

I was near the reef edge when Ron's cries filled the air - 'Another new record', he exclaimed. Just as I arrive at the spot, he found another one of this species (*Holothuria notabilis) a few metres away from the first one, covered beneath small hills of sand.

I was delighted with my luck to have this Sea Cucumber lying in my path! I meekly asked the others what this Sea Cucumber was, fearing a kok on my head if its one that I was supposed to know, and was overjoyed that this is yet another new record! I'm not quite sure of its ID (*Bohadschia vitiensis), but we thought it looked like the Golden Pillow. =)

The entire body is covered with papulae which is said to have some sensory functions.

The trip ended on a high note with July's find of a Pentaceraster Sea Star (Pentaceraster sp.), which was sighted only once, 1 year ago.

This is certainly one of, if not, my best trips to Semakau, being treated to the exciting first records, as well as the usual beautiful sunset. What really struck me on this trip was that the RMBR folks have been there for 5 years now, and yet there is an neverending list of first records at Semakau. With such rich marine life on this island, it will really be such a waste if the habitat is lost to the development of the area.