Blog Log! September 30!

Lee WenKeeping my fingers crossed during the week seemed to work. Bright sunshine and great visibility meant first timers on our trip were lucky to experience Hantu at one of its best. Above, diver Lee Wen descends into the depths.
Blue dragon nudibranchBlue dragon nudibranchBlue dragon nudibranchMany on the first dive got to see lots of nudibranchs Reef Xplore guide Ming Sheng quoted “11 species” of nudibranch! I didn’t get to see that many species, but surely they seemed in a higher density than usual. Perhaps it was the sunlight that brought them out; not just illuminating them, but an organism called zoxanthellae that it ingests when feeding on coral produces sugars with the suns energy, much like plants and photosynthesis.

Icon SeastarIcon seastarIcon seastarThere were also several Icon Seastars – a rare and threatened species that occurs often in Hantu’s waters. The one above seems to have a parasitic mollusk attached to the surface of its body. These beautiful seastars became threatened simply because of the way they look. Unregulated and unmonitored harvesting for sale and collection as curio threatened this species survival. To be sure you don’t contribute to the trade, don’t buy any marine souvenirs wherever you are.

Paradise whiptalI’ve not photographed this critter for a long time – the butterfly whiptail is one of my favourite fish on Hantu’s reefs. It’s curious nature often brings it close to divers, especially when you remain absolutely still. Similar to another fish found on our reefs called the Paradise (White-shouldered) whiptail, the Butterfly whiptail is more strikingly coloured despite its more modest name.

GonioporaCoral reefCoral reefWhip coralA bright sun-shiny day is always good for appreciating Hantu’s amazing diversity of coral.

Tube wormTube wormTube wormTubeworms are another favourite of mine. Although they don’t have a very attractive name, their patterns, colourations and even behaviour can be fascinating to observe. One should take note that observing tubeworms requires ALOT of patience! If you settle along one for long enough, you will see how it orientates its feeding appendages to siphon out food from the passing water most effectively. Today I saw a truly tiny and adorable tubeworm just a few millimeters in diameter. It was easier to startle than its larger counterparts and so I was unable to photograph it.

GymnodorisGymnodorisPhyllida seaslugTwo of the “11 species” of sea slugs Ming Sheng accounted! On the left is the Gymnodoris nudibranch is “known from Indonesia and Singapore and recently reported from Hong Kong and Tanzania, this species has a wide Indo-West Pacific distribution. It has similarities in colour pattern to G. ceylonica but the orange spots are much larger and more densely arranged, the body is more elongate and the gills relatively small. There are also major anatomical differences”* On the right is the Phyllida seaslug, a common sighting on Hantu’s reefs. Some inidivduals have been found as large as a clenched fist! One wonders how many hydroids and years it took to create such a monstrous size!

Longfinned BatfishLong finned BatfishLong finned BatfishLong finned BatfishThis is just one of the 3 batfishes we saw today. Two of them were sighted just at the surface of the water near our boat. I cam across this individual just as we began the second dive. It was so conspicuously places above a crop of whipcoral that I just had to take a picture. However, my approach was poorly timed and I startled the resting fish which swam into the distance promptly (far left picture). Towards the end of the dive, as we reciprocated, I noticed the same individual had returned to the same coral outcrop to rest in the same position it had earlier. This time however, I timed my approach and kept taking pictures as I approached it. It was a wonderful experience to have been granted to opportunity to photograph it.

Tigertail SeahorseFinally, everyone’s favourite! The seahorse. Everyone wanted a seahorse today, and it was extremely stressful! No doubt most of our dives are blessed with seahorses, you never quite know when you are going to see one. Thanks to tips from the other reef guides though, I managed to find this one, clasped tightly onto coral, facing away from the camera. It’s not visible in the picture but this individual was “expecting”. Male seahorses are the ones that carry and “give birth” to young seahorses. Chay Hoon said he spotted another “expectant” dad on another location, which might mean it’s Spring time in the sea! Time to have lots of babies!

Picture 2Polyclad FlatwormTo round it off, I saw this shy and solitary Kite Butterflyfish (left) swim right past me as I was exiting the second dive. The above is a frame grab from a video I shot, hence the low resolution. It may look similar to the Copperbanded (Long beaked) Butterflyfish, but it differs with its “triangle shaped body, four brown bars on sides and a black ocellus (spot) on soft dorsal fin.”** It occurs solitary or in pairs, over reefs and also in estuaries, feeding on coral polyps and small invertebrates. It is a popular aquarium fish. The Kite Butterflyfish is less common than the Longbeaked, and while it is reputed to be found in pairs it is more often sighted solitary in Hantu’s waters. Don’t buy marine fish from aquarium shops unless it is certified that they have been farm reared. The picture on the right is a brilliantly-coloured polyclad flatworm strikingly contrasted against a red encrusting coral.

Stay tuned to the blog to see cool videos of underwater Hantu from this weekend’s dive!

* Source: The Sea Slug Forum

** Source: A Guide to Common Marine Fishes of Singapore

1 thought on “Blog Log! September 30!”

  1. It’s actually 8 spp. I said after the first dive 🙂 but after the second dive and combining everyone’s sightings, it’s more than 11 slugs!

    Pteraeolidia ianthina
    Phyllidia pustulosa
    Phyllidia varicosa
    Phyllidia ocellata
    Gymnodoris rubropapulosa

    unknown orange Gymnodoris?
    Hyselodoris bullockii
    Chromodoris lineolata
    Glossodoris atromarginata
    Chromodoris lineolata
    Bornella stellifer
    Ceratosoma trilobatum
    Chromodoris fidelis
    Jorunna funebris

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