Monday, January 12, 2009

Changi Beach Over Two Days

Went to Changi beach recently over two days - one was an exploratory trip, while the other was to conduct a shore ecology workshop for MGS.

Been really busy these days, so here's just a quite listing of some of the things we saw.

Ovum cowrie (Cypraea ovum) - a rather common cowrie on our northern shores, and also regularly spotted on our southern shores. It feeds on algae.

Two different sponges competing for space on a piece of rock.

Biscuit sea star (Goniodiscaster scaber) - we regularly see this sea star on our northern shores. Some of the nature guides felt it looked like a biscuit, and thus it had been stuck with this common name.

Hairy sea hare (Bursatella leachii) - Seasonally common, we have been regularly seeing lots of these sea hares usually at the beginning of the year.

Sponge crab (Cryptodromia sp.) - A rather cute crab which carries a sponge or ascidian, nipped to fit onto its carapace to camouflage itself.

Haddon's carpet anemone (Stichodactyla haddoni) - One of the more common anemones in Singapore, and so far I have seen it on most of our shores. The largest population I have seen was at Chek Jawa before the mass death 2 years ago. Even though most of them were gone after that, I guess Chek Jawa probably still has one of the biggest population of these anemones in Singapore.

Swimming anemone (Boloceroides mcmurrichii) - Also seasonally common, we can sometimes find lots of them, and yet at other times, none at all. It is able to drop off its tentacles like a lizard dropping its tail to distract predators.

Pink thorny sea cucumber (Colochirus quadrangularis) - Again a seasonally common animal, and can sometimes be found in huge numbers on our northern shores, though I have seen it once in a while on some of our southern shores too.

Frog shell (Bufonaria rana) - I seldom keep a lookout for shells usually, so I'm seriously not sure if this is common or not. Understand that they found it at Chek Jawa recently too, so guess it can't be really all that rare.

Mangrove whipray (Himantura walga) - These two rays were caught by a fisherman. They were sometimes mistaken for horseshoe crabs, and vice versa.

There were several colonies of hydroids growing on the rocks. Brushing against them could mean a painful experience, as these animals sting.

Coastal horseshoe crab (Tachypleus gigas) - We found this on the high shore actually. Wonder what it's doing up there. We initially thought it's a moult or a dead one, until it turned and headed back into the water.

There were tons of zoanthids on some parts of the shores, looking like a garden full of little purple flowers.

I have no idea what the white ball is. Could it be some egg capsules? The black patch next to it was a hoof-shield limpet (Scutus unguis). It really appeared like a slug since its mantle covered its shell much of the time.

Chitons are quite common at Changi, but you need a lot of patience to find them since they are usually rather well-hidden under rocks or dead shells.

Sand stars (Astropecten sp.) - Probably the most common sea star in Singapore, you can sometimes find them in the hundreds. So far I've only seen them on shores of the main island northern islands though, but not the southern islands.

Spotted seahorse (Hippocampus kuda) - I was rather happy to find a seahorse despite the not-so-low tide.

Salmacis sea urchin (Salmacis sp.) - This sea urchin is also seasonally common on our shores, and we can sometimes find hundreds of them along the northern shores.

Noble volute (Cymbiola nobilis) - This huge snail can be regularly found on many of our shores. It feeds on other seashells.

Orange striped hermit crab (Clibanarius infraspinatus) - Thought it was rather interesting to see this hermit crab using a land snail's shell.

Lined moon snail (Natica lineata) - A very pretty moon snail was found by RH towards the end of the workshop. This is another predator of other snails.

Will be having more workshops at Changi soon. Sure hope to see more interesting stuff! :)


Anonymous said...

some great finds as ever. I love the ray and the horsehoe crab.

As for the white ball it looks similar to something we get on our shores, which are the eggs of a whelk. (A whelk is a largish predatory gastropod/sea snail, just in case you dont know). there a photo of one laying eggs here

and one of the eggs here

hope that helps

Ron Yeo said...

Thanks Neil for the info! :)