Monday, November 08, 2010

Higher Than Expected Tide at Changi

Something seemed to be wrong with the tide table these few days - the tide was somehow much higher than predicted! I went with Robert to Changi Beach today, and was certainly rather surprised to see most of the seagrass meadow still under water. But despite the higher than expected low tide, we still had a surprise find!

Notobryon Nudibranch
We found this slug stranded on the sand. It was about 8cm long. Initially, I thought it was a Melibe, but after putting it back into water, I realised that I was wrong. It didn't have the "hood" that a Melibe used to catch its prey.

Notobryon Nudibranch
When it started to relax and move around, I also noticed that it started extending some branching structures on its back - these were retracted earlier when it was stranded on the sand. While it was not a Melibe, it still looked like it should be from the same suborder, Dendronotina. The general shape, especially the head and rhinophores, reminded me of the Sargassum Slug, Crosslandia sp. Back at home, I searched through my Nudibranch Encyclopedia and also the Sea Slug Forum, but couldn't seem to find any Dendronotinids with such extensive and huge branching structures and also resembles the slug we found.

Notobryon Nudibranch
The closest would be Notobryon wardi from the Family Scyllaeidae, which also happened to be the family that the Sargassum Slug is from. So I guess this is probably a Notobryon sp.

Porcelain Crab (Porcellanella picta)
As we explored the other parts of the shore, we noticed several sea pens being wash ashore, and found Porcelain Crabs (Porcellanella picta) in some of them.

Porcelain Crab (Porcellanella picta)
Here's another one.

Colochirus quadrangularis
We bumped into Peirong who was doing a research on sea cucumbers. There were quite a number of these Pink Thorny Sea Cucumbers (Colochirus quadrangularis) around.

Sand Stars (Astropecten spp.)
As the tide was not that low and only a small part of the seagrass meadow was exposed, we did not managed to find many sea stars also. Most of the Sand Stars (Astropecten spp.) we saw were in fact the ones being washed ashore.

Biscuit Sea Star (Goniodiscaster scaber)
We only managed to find one Biscuit Sea Star (Goniodiscaster scaber).

The little patch of seagrass was only exposed for a little more than half an hour, and it was covered with water again, and hence we ended our exploration early. Well, I guess I will come back again when the tide is better :)

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