Jul 31, 2008

Curious Cucumbers of Changi

This morning, we seemed to have encountered quite a few strange sea cucumbers on Changi. Although the common name is sea cucumber, these are animals and not vegetables. They belong to Phylum Echinodermata which includes sea stars, sea urchins, sand dollars and feather stars.Marcus found this cuke. This is the second time we've seen it, the first time also on Changi. It has an obvious underside and not very long tube feet.

Robin was very interested in having a look at it, but we didn't find it when we went with him. At first, I thought the sea cucumber above was a 'cleaned up' version of the sea cucumber below. But when we went sea cucumber searching with Robin a few months ago, he pointed out that this 'sandy' sea cucumber is not covered with sand. It actually resembles sand in texture and colour!And here was another strange sea cucumber tucked up against a Window pane shell and other debris. It had really long tube feet arranged in rows along the body.And YET another sea cucumber that I can't recognise. It seems to have its long tube feet in rows along the length of the body.There was this elongated sea cucumber with tube feet all over the body. It was very active, moving about in the water, stretching out and contracting. I'm not sure if it's a rather active Ball sea cucumber (Phyllophorus sp.) or some other kind of sea cucumber.Of course, there were lots Thorny sea cucumbers (Colochirus quadrangularis) which have soft 'thorns' on the upperside and a distinct underside with rows of little red tube feet.Less commonly seen is the Warty sea cucumber (Cercodemas anceps). Also seen were lots of ball sea cucumbers buried in the sand bars (Phyllophorus sp.) together with smooth sea cucumbers. As well as one Sandfish sea cucumber (Holothuria scabra).

Changi is a great site for echinoderms!

Today we saw more sand dollars than usual. Usually, we see only a handful. But today, there were quite a few close to one another on several parts of the shores.There were lots of sand stars (Astropecten sp.) of various sizes.And one star with only one complete arm!
There were also tiny ones with a different pattern.
Several of them actually.And here's another one.
We will await Kok Sheng's study to find out whether these sea stars are different species or just different patterns of the same species.

If anyone has ideas of about the identities of these animals, please do share. Constructive views are always welcomed so that we together we can learn more about our shores.

Kok Sheng saw even more splendid stars today at a different part of Changi! More on his wonderful creations blog.

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