Friday, January 9, 2009

St John's northern shore

This hot and windy afternoon, I took some time to explore the northern sand lagoon of St John's Island during low tide alone. The rest of the gang were star tracking at Cyrene Reef instead.


Singapore is well known for its high population and every where you go in the mainland, there are crowds especially near shopping malls or tourist attractions. As for today, it was a totally different feeling. Alone in this vastly exposed sandy lagoon I felt it was peaceful. Nothing like the busy hectic lifestyle that many Singaporeans lead their lives everyday.


So what is so nice about this lifeless looking sand lagoon built for people to swim during high tide? If you bother to take a closer look, there are star marks on the ground! No, the stars from the sky didn't fall into this lagoon, but there are starfish aka sea stars!


There are several common sea stars (Archaster typicus) that created those star marks on the sand.

Also on the lagoon are soldiers of tiny creatures scurrying around.


When I got closer, all went to hide and this one was in the midst of hiding from me.


Indeed, they are the soldier crabs (Dotilla sp.) that are often moving around in large groups at low tide. This habit of 'trooping' in numbers gave these crabs their common name.


This is their typical burrow with small and big sand balls around the opening.


How about other crabs? There are of course many of the cute fiddler crabs.


This one has a much bigger claw (bright orange coloration) used to attract their female counterparts.


This is a female fiddler crab, because it doesn't have a fanciful huge claw on one side. This one has a slightly different carapace coloration, with a tinge of light blue.


Interestingly, there are massive groups of creeper snails seemingly feeding on the algae in the lagoon.


Soon, I took the remaining time to explore Tanjong Hakim, where the natural rocky shores are. Unfortunately, the tide was not as low as ideal so I did not managed to venture too far out, in fear of Mr Stonefish which has been spotted here before.


There are many soft corals around this rocky shore.


Soft corals are different from hard corals in that their tentacles come in eight (or multiples of eight) per polyp. Don't you think the individual polyps looks pretty too?


Hard coral tentacles come in six (or multiples of six) per polyp and there are also hard corals found. Near and on hard corals are other living organisms as seen in this photo.


Can you spot this black long sea cucumber from the previous photo? A closer look reveals a commensal shrimp on the sea cucumber! Cool. I didn't know until I got back home to process the photo.


Another creature growing on top of the coral boulders is this pair of stunning fan worms.

According to the Wildfacts page, Fan worms live in a flexible, leathery tube. The tube is often much longer than the worm. Some fan worms have eye spots on their tentacles to detect movement. Fan worms will slip instantly into their tubes at the slightest sign of danger.


There are also mats of different types of zoanthids found.


How about anemones? Yes there are. This is a giant carpet anemone (Stichodactyla gigantea) that are known to house nemos. Unfortunately there were no nemos in this anemone.


I also sighted several of this Frilly anemones (Phymanthus sp.).


During the day, most mobile creatures are hiding from the sun so you really need to look closely to find them. Just like this bristleworm that was crawling from underneath the rock.

Would love to come back again to this shore during a lower low tide the next time. :-)

No comments:

Related Posts Plugin for WordPress, Blogger...