Saturday, July 14, 2007

Changi Surprises

The tide was at its lowest at 3 am today, and was up and arrived on the eastern part of Singapore at about 2:30 am to meet with the Semakau Guides for a field trip.

First time for me and indeed this place was full of surprises, one of our richest shore and also one of the most poached. In this early morning, we have seen people walking around collecting specimen with net and "changkul" (a mix of shovel and pickaxe). What were they harvesting, this we do not know as it was dark, and this guy had a changkul, we were only armed with flashlight and camera.

Still there were plenty of surprises. Today being a new moon, I was told by my father that crabs (crustacean) tends to shed their old shells (moulting). This was true today, for there were a lot of discarded shells from the Flower Crabs (Portunus pelagicus), and we witnessed one in the process of "undressing". Upon shedding their old casing, the new casing is very soft (the edible soft shell crab) - the crab will quickly gulped in water to expand before the new casing hardened.

First and foremost, this place was filled with sea grasses of the Spoon seagrass (Halophila Ovalis) and Fern Seagrass (Halophia Spinulosa), then among these sea grasses were brittle star, pipefish, flatfish. Well the list goes on, look below for just some specimen.

There were alot of Sand Stars (Astropecten sp), managed to take closed up of the body and legs. From the upper surface, the pattern on the skin is rather unusual.

Moon Crab (Matula Lunaris) - Tonight there were many of them swimming in the water, with 4 pairs of paddle like legs, they are very good swimmers. Not only good swimmers, but also good burrowers. With those legs, they disappeared into the sand very fast.

Pipefish (Family Syngnathidae) - a closed relative of the sea-horse. Looks at the mouth and its side fins, if only the head was shown - it will be difficult to differentiate them. (Seahorse or pipefish).
Flatfish started their fry stage like most fishes, eyes on both side of their bodies. Soon as it grows, one eye will start to migrate to the other side, and soon it becomes a bottom dweller. See the pair of eyes.
Geographical Sea Hare (Syphonota geographica) is a nocturnal creature, and we were fortunate to see them on this shore. Hardly you will chance upon them in daylight, as they will have burrowed into the sand. A very shy creature, but tonight they seems to be out in force. This Striped Hermit Crab (Clibanarius sp) seems to be loaded with passenger. Empty shells on the shore may eventually become homes to another organism, thus the policy "take pictures only". This hermit has make its home out of the Noble Volute shell.
Sanddollar - a relative of the sea star. Burrowing in the sand, but leaving behind round impression giving away their hiding place. We saw plenty of this Sand dollars. Observe the next pictures, and you will understand how they can burrow themselves into the sand.
(the legs of the sand dollar)
The next 3 pictures is an animal, we suspect to be a Sea Anemone with its body outside its shelter (hole). We don't know, maybe you can shed some idea.

(the business end)
(Is this the burrowed and the same one?)
The Moon Snail (Family Naticidae) is a fierce predator. This shot was taken with the snail scavenging for buried snails and clams as it bulldozed through the field of sea grass. We saw a lot of sand collar, which is the sand + egg capsules mixed of this snail.
This Ghost Crab a very shy animal, but for tonight it chose to stay for us to finish taking pictures, and only to demonstrate how quickly it can run, we touched it, and did we witnessed a sprint that even surprised us. Sprint about 5 m and quickly burrowed into the sand.

There are many more happy memory of this morning "foraging"in this eastern shore, unfortunatly time and blog space is limited, till another time. Thanks for reading.

Friday, July 6, 2007

Semakau Landfill Intertidal Walk

RMBR plays host to the Singapore Shanghai International School (school set up by Singapore in Shanghai for expatriates working there). The students are here for 5 days and in their itinerary, Semakau Landfill Intertidal Walk was one of the attraction.

There were 18 of them, children from Asian countries (Japan, Korea, India, Malaysia, China and of course Singapore)

As you can see, they were a curious lot! This was the beginning of the walk and theirs eyes were everywhere.

We came across this baby Mangrove Horseshoe Crab (Carcinoscorpius rotundicauda), it was a juvenile. The Mangrove Horseshoe Crab has a tail that is round in cross section, vs the Coastal Horseshoe Crab (Tachypleus gigas) which is triangular.

In single file, they crossed the Sea Grass meadow, and pulling their shorts and pants along the way. Afraid of getting wet, it will be a vain attempt - for coming back the tide would have raised the level! Surely their pants will be wet.
Demonstrating to the students that Sea Cucumber (Holothuria scabra) will right itself when placed upside down, the picture below shows just that.
We found a bigger than usual Heart Cockle (Corculum cardissa), a bi-valve but open its shell sideway, just like the pincer of the crustacean.
Another view of the Heart Cockle, but the side that lies on the sea floor. Here the parting-line is very obvious.
Trodding along, the Fiddler (that is the name of my group) made it to the Coral Rubble area. Soft and Hard Corals abound, but today the weather was hot and most sea creatures preferred to take their siesta than to come out and display, except for those that are still covered with water.

Below is a hard coral that is easily mistaken for anemone. Even the name gives you that hint - Anemone Coral (Goniopora spp)
Below is a mushroom coral (Heliofungia actiniformis) with its long tentacles.

It must have been the heat, for most creatures just "disappeared". We managed to locate one Knobbly Sea Star which normally should be a couple. Still, a memento we must have, and here you can see the Fiddlers with it.

On our way back, we came across this Noble Volute still in the process of laying eggs (Cymbiola nobilis). The egg capsules is translucent and somehow "mathematically"it does add up. How did those mass of egg capsules come from that shell?

Today seems to be a very odd day - the tide at its lowest should be 0.3m but it seems to be lowered than that, and the tide seems to be in this stage for a long time. We arrive at 8 am, and left at about 10:30 am, and there seems to be no change to the tide. At least the Fiddlers did not get more wet than I have predicted!!!