Jun 30, 2007


Chay Hoon is the most lady-like person I know. It was thus quite a shock to hear her yell "Basket!" on the shore.

Closer attention to what she said, and I realised what she exclaimed was "Basket STAR!"
And it IS indeed something to get excited about! It's our first ever sighting of this strange animal on the intertidal.
The basket star is a relative of the sea star. At the centre (right closeup photo) you can see the five arms emerging from a central disk. It's just that in a basket star, the arms divide into many curly branches! (left closeup photo). Isn't just an amazing animal?!

We were out very early at Sisters Island on a bright full moon morning.

Shortly after we arrived, Chay Hoon found a baby Razorfish (Family Centriscidae). It was all alone, although she did look around for its friends. Usually, these odd fishes are found in groups. They hang head down, often sheltering among the long spines of large sea urchins, but swim horizontally too.
The halfbeak (top left corner) swims horizontally on the surface of the water. Other little fishes were also sheltering in the pools left behind by the tide.

Another of Chay Hoon's smashing finds was this smasher mantis shrimp. The mantis shrimps we usually see at Changi have spiny arms just like the land praying mantis insect. But this green mantis shrimp has clubs instead of spines on its arms.
These clubs can be used to give a really hard whack! To discourage predators and to stun prey or crack shells.
Unlike Chay Hoon, I am not good at finding spectacular things. Generally I only spot marine life that don't move much or at all. I came across these little Anchor corals.
As well as a sea anemone with bulbous tentacles (Entacmea quadricolor). The Tomato anemonefish usually shelters in this kind of anemone, but I didn't see any of these fishes.
I also chanced upon a busy little octopus hardly bigger than 10cm. It was perfectly camouflaged as it skimmed over the coral rubble in search of breakfast.
It stopped now and then, unfurling all eight long skinny arms in eight different directions, to poke about in nooks and crannies.When it discovered something tantalizing, it immediately flared out the webbing between its arms so the octopus became a little net!
I noticed that many of the living hard corals today were rather brown. A closer look revealed that they were covered with a layer of tiny acoel flatworms!
These very small flatworms are believed to graze on the small animals trapped on the mucus of the host coral, e.g., small crustaceans, copepods, diatoms, detritus. I'm not sure if the worms hurt or help the coral in the process. Here's a closer look at the worms.
I've seen small groups of these acoel flatworms on hard corals, but never so many before.

All too soon the tide came in and the sun rose to a dull and lackluster sunrise (what we call a "power failure sunrise"). But we were still busy checking out the shore. Almost forgetting our breakfast cooler which we left on the shore so the wild monkeys wouldn't raid it.
The cooler nearly floated away! Fortunately, Helen saved it.

Today, the reefs of Sisters were very quiet compared to our previous visits. All the seaweed was gone, both sargassum and bryopsis. The rubble was drab, when usually they are coated with pink, blue and other colourful encrusting animals. And there seemed to be a lot of sand, with many of the hard corals half buried. We're not really sure what is going on and whether we should worry.

This is why I feel it's important to make regular visits to our shores so that we can keep track of what is going and get a better sense of seasonal changes.

Lots of other marine life were sighted too! See these other blogs about the same trip ...
tidechaser blog with sightings of "Nemo" (clown anemonefish), anemone shrimps, strange sea cucumbers,
wonderful creations blog with sightings of colourful crabs, blue-spotted stingray
where discovery begins blog with sightings of land hermit crab, brittle star, marine spider

1 comment:

Anonymous said...

Pretty nice blog you've got here. Thanks the author for it. I like such themes and anything connected to this matter. I definitely want to read more on that blog soon.

Best wishes