Aug 1, 2008

Special snails and strange worms on Changi

4am and we're on Changi! How wonderful to see this thriving shore after having seen the one on the East Coast!

Here's some of the stuff I thought was special. This morning was the first time I saw a living murex snail! This is probably the Rare spined murex (Murex trapa) which is listed among Singapore's threatened animals.It has a long muscular foot, with the tear-drop shaped operculum attached to it which is the 'door' that seals the shell open when the animal retracts.The snail tucks the operculum upwards when it sticks its narrow foot into the soft ground. You can also see the very long eye 'tentacles' that the snail has.

Further along, I saw another living murex which had something clutched its narrow foot.A closer look reveals that its prey is some kind of clam.I'm not sure if the bluish colour is the colour of the clam shell or due to something that the murex shell was doing to the clam.

Just a few steps onto the shore and Chay Hoon spots this sea cucumber... no, wait ... sea anemone... err ... wat IS it?! It was only after we saw the spoon shaped thing on one end of this tubular animal in pajamas, that we realised it was a spoon worm or echiuran (Class Echiura, Phylum Annelida). A spoon worm has a spoon-thing, called a protomium, is found in front of the mouth. The protomium can extend up to 10 times its retracted length, in some species, reaching 2m long! In most, the protomium is used to gather edible bits from the surface.

Many live in U-shaped burrows in shallow water, others in rock or coral crevices. Apparently, echiurans may be important food for some fishes. In a study of Leopard sharks off California, large, meaty spoon worms were found to be their favourite food.

Here's a drawing of a burrowing echiuran called the Landlord worm found in the U.S. east coast (Taken from Barnes' Invertebrate Zoology). Apparently, its burrow is so comfy that tiny clams and crabs quickly settle in with the worm.

I wonder what our spoonworm does? Lots more to find out about our shores!

Here's some tubular stuff that look similar to the echiuran.A peacock anemone retracted into its tube on the lower left, and a long smooth sea cucumber diagonally across the photo.

Another strange worm-like thing was this one.Here's a closer look at the icky, stringy parts on the front of it.Is the smooth pink worm with the yellow hair things eating the segmented bristley worm?

The pink worm looks quite similar to something Marcus found yesterday, also at Changi.It was quite scary looking with lots of transparent strings and a coiling yellow portion.

These worms with strings might be terebellids (Family Terebellidae, Class Polychaeta, Phylum Annelida). These burrowing worms are also called spaghetti worms because the stringy long tentacles on their heads are all that is often seen above ground. Here's more about terebellids on the Polychaetes of Singapore website.

Changi is among the few places where you can be almost certain to see the fascinating black phoronid worms (Phylum Phoronida) that cluster around peacock anemones.This is the largest cluster of phoronid worms that I've seen so far. Kok Sheng spotted it and we both had to sneak up gently to them to avoid scaring them into retraction.I think these delicate spiral pink-and-black feathery worms are very elegant!

Seahorses are so commonly encountered on Changi that we have taken them for granted.Those seen on Changi are often bright orange or even reddish. We saw three seahorses today.Unfortunately, one of them seemed to have suffered some sort of laceration across the body.

The shore has much debris, abandoned fishing lines and even this very large abandoned drift net.In fact, Chay Hoon spent quite some time freeing a horseshoe crab that was trapped in an abandoned net. And she did it without scissors! She improvised and used a clam shell!

Hopefully there will be more love and care of these wonderful Changi shores. So that Changi does not suffer the fate of the shore that we abandoned at the East Coast this morning.

We also saw lots of special sea stars today. Here's more about those stars and other special encounters on Kok Sheng's wonderful creations blog.

1 comment:

Swamper said...

Changi Ferry Road and the last car park along Changi Beach. Look for Changi Ferry Terminal sign boards! FREE parking! Can wash yourself in the toilet right next to the car park! Thanks for all the clues! Fishermen paradise!