Back to Big Sisters

Hey all, the low tide season starts again... and the first adventure we all had required a boat ride to an offshore island: Big Sisters Island. Today's Vesak Day and it's good to spend a holiday exploring our natural shores.

Wait a minute, I also realized that my last trip to the Big Sisters Island was also on last year's Vesak Day! So it has been one whole year since I've set foot on this island :-)


Sisters Island has nice accessible reefs for any ordinary Singaporeans to explore if you charter a boat ride there. The corals are colourful especially at night where they extend their polyp tentacle out like this faviid coral.


This greenish Boulder pore coral (Porites sp.) look interesting because it has spots surround with pink pigment on the coral boulder itself. What does this mean?


Another hard coral spotted with be this Carnation coral (Pectinia sp.).


Strangely, the mushroom corals (Family Fungiidae) today seemed to be lesser and I only saw three living ones in total today.


The branching form of this tiny colony of Acropora coral (Acropora sp.) interestingly looks similar to the branching sponge beside it. :-)


It is almost a sure thing to spot this Frilly anemone (Phymanthus sp.) in reefs or coral rubble area.


More frilly animals include the colourful assortment of Fan worms (Family Sabellidae) like this orange fan worm (left most) and the banded fan worm. And at the right most you can see this tiny anemone like creatures in brown and light blue which actually are Corallimorph (Order Corallimorpharia). Most corallimorphs harbour zooxanthellae (symbiotic algae) inside their bodies. The symbiotic algae carry out photosynthesis and may contribute nutrients to the host.


There were lots of worms spotted as well! Perhaps you might not feel comfortable when you hear about worms but marine worms are really pretty! Like this Very long ribbon worm
(Baseodiscus delineatus) which is actually a very voracious predator!


Another delightful wormy find will be this pyschedelic Three stripe flatworm (Pseudoceros tristriatus). It has a pair of erect pseudotentacles at the front made up of folded edges of the body.


Another bluish flatworm spotted will be this Blue-lined flatworm (Pseudoceros sp.). As you can see, it has one blue stripe along the length of the body. The line ends with a little blue circle-dot near the head.


The third flatworm that I found at the reefs will be this graceful Brown striped flatworm (Pseudobiceros gratus). It decided to make a swimming performance for me which was fantastic! Yes, marine flatworms can swim by undulating the sides of their bodies.

How about the slugs? Yes I managed to spot a few of them too!


One of them will be this Ornate leaf slug (Elysia ornata) which is believed to eat the Hairy green seaweed (Bryopsis sp.).


I also spotted a pair of this commonly found Black-margined nudibranch (Glossodoris atromarginata). My previous trip experience seem to tell me that they like to gather in pairs or trios. The starry structure on the body of this sea slug is its feathery gills which have the ability to rotate constantly. This is believed to help improve respiration.


Another nudibranch spotted by Chay Hoon, of course, is this tiny little Pimply phyllid nudibranch (Phyllidiella pustulosa).

Not a very sluggy day at Sisters today but it's ok because there are other surprises too!


Though the Wandering cowrie (Cypraea errones) is commonly sighted, it has a beautiful shell that I enjoy looking at. Unfortunately, their pretty shells are highly prized and thus cowries are overcollected to be sold.


Another snail that I found at the higher shore area will be this stunning orange longish snail that is alive. I wonder what exactly it is.


Kaiying aka Janette had quite good crabby finds like this couple of tiny crabs that look distinctly apart colourwise. She also spotted a mosaic crab handling a sea urchin, probably for a makam (eating) time! Hope she blogs about it soon... heard that Kaiying?


Today was quite a fishy day, as James discovered, and it was nice of Marcus to spot this Painted scorpionfish (Parascorpaena picta). Though they look harmless to you, they are dangerous fishes!

The common name of these fishes comes from the stinging pain that they can inflict. When stepped upon or mishandled, the stout spines on the dorsal fins can inject venom into the offending foot or hand.


Another marine fish spotted among the rocks will be this gentle Carpet eel-blenny (Congrogadus subducens). They are usually mistaken for being a snake. Yet it is not even an eel too. Haha!


More fishy business went on when I encountered a school of Striped eeltail catfish (Plotosus lineatus). Young striped eeltail catfishes are often found swimming together in a 'ball' of hundreds of fishes, constantly moving but remaining in a ball. Andy got a video of it and he'll share with us soon! :-)


Chay Hoon spotted this large strangled Octopus and later released it in a pool of water. Hope it recovers from the stress of being out of water.

Now...drumrolls... for the special finds of the day!


First special find will be this Fluted giant clam (Tridacna squamosa) spotted by Alex! I guess Mei Lin (who does research on them) must be happy that another giant clam has been spotted.


The next special find will be this gigantic mantis shrimp (Order Stomatopoda) that I spotted near the high shores! It looks different from the usual mantis shrimps previously spotted at our shores. The pincers of some mantis shrimp are so powerful that they have been known to break aquarium glass! I definitely will not try to handle this creature will be bare hands!


The next special find is just beside the previous special find. Yes, there was a tiny yet pretty shrimp beside the huge mantis shrimp.


In fact, there is a couple of these shrimps near its burrow. I saw a total of three of these shrimps! I like their pinkish body and they look really cute as cartoon. Wonder what kind of shrimps are these.


And FINALLY I got to see the Yellow-lipped sea krait (Laticauda colubrina) for my first time! All thanks for Geraldine for spotting it. The tide was coming in real quick, thus the water was quite murky.


Nevertheless, I got to follow this snake underwater for a while! The yellow-lipped sea krait has a highly toxic venom but is docile and will not bite unless provoked.


It seems to be being a good place to burrow or hide into. Haha.

The final special find will be by Andy!


Yes, finally I got to also see the Hollow-cheeked stonefish (Synanceia horrida) for the first time too!

I hear of this fish 100 times more than I get to finally see it alive. Why? It is because they have tough dorsal fin spines that can penetrate thick soled shoes. These act like hypodermic needles, injecting a venom that can be fatal to humans. Stonefishes produce neurotoxin that is considered the most deadly of the fish venoms.

How to avoid? Very hard... because it really looks like a stone. So the only solution is try not to step on stones at the shores, which is yet another challenge especially at the coral rubble area.

I thank God for His protection on me that I've not stepped on a stonefish yet. Phew...


This particular stonefish spotted was really small as compared to the ten cent coin.


Very soon, the sun rose, the tide returned and we called it a day.

Today was a great day, with different people spotting different great finds. But these trips are only possible if the weather permits. We had to almost abandon the trip because of the sudden gust of wind and rain that arrived when we stepped foot on the island. Following that were lots of light shows in the night sky (aka lightnings). Thankfully, Sisters Island was particularly not affected by all these and we could continue exploring after waiting at the shelter for 45 minutes. Pray that tomorrow's trip will be filled with fine weather.