30
October
2007
The monsoon season is here but it’s still quiet down at Hantu. Just as well! The Hantu Blog left with a full boat of divers this weekend and comprised several nationalities - from the UK to US, and India to Western Europe. Of course, most of us were seasoned locals who just couldn’t wait to discover another day of diving at Hantu’s every surprising reefs!
Our first dive of the ay was relatively quiet less a few angry damsels. We encountered a pair of nonchalant Copper banded Butterflyfish which were quite happy feeding and didn’t mind being photographed. I also spotted a patch of algae growing on a coral head (second from left). There’re several factors that could lead to algae blooming, one of the most common reasons along developed coasts is the runoff of fresh water. Speaking of runoff, it was mentioned in a UN report released just this week that there has been “a rapid rise of “dead zones,” where marine life no longer can be supported because pollutants like runoff fertilizers deplete oxygen.” Luckily for us, there’s still lots of corals to be observed and the algae growth around Hantu (at least so far) seems to be in isolated patches.
Can you spot the filefish in the photo on the far left? It’s got its tail facing the camera. What’s amazing camouflage! Another critter that seeks safety amongst coral is a tiny tube worm (2nd from the right). Can you see them? They’re the tiny, salmon-coloured nodes that seem to be sticking out of the coral. They’ve got themselves embedded within this Favia boulder coral and that’s probably where they will stay for a long time, harvesting food from the current and growing deeper within the coral. On the far right, a colony of zoanthids.
As we moved along the dive, we came across two separate schools of razorfish, also called shrimpfish. They comprise four small species of tropical marine fish and can be found in the Indian and Pacific Oceans.
Razorfish are nearly transparent and flattened from side to side with long snouts and a sharp-edged belly. A thin, dark stripe runs along its body. It is from this and their shrimp-like appearance that their name is derived. They swim in a synchronized manner with their bodies pointing down.*
This is the first time I’ve photographed the Three Saddle Cardinalfish in Hantu waters. They appear less common than the other species of cardinalfishes which can be spotted amongst Hantu’s plate corals. This fish may be found in marine, brackish, and freshwater environments and is primarily marine. It is known to be nocturnal and can be commonly found in the aquarium trade.**
On the second dive, we explored the deeper depths and searched amongst the whip corals for interesting lifeforms. We found (L-R) allied cowries, crinoids, and whip shrimp.
I also came across this brilliant coral and I think it is a Black coral - the only coral in the world that has been listed as a threatened species by the United Nations. Usually you’d see them with red or orange-coloured polys. It is called Black coral because unlike most corals, its skeleton is black instead of white, as is observed when most corals die or get bleached. It became a protected species because its trade in the aquarium trade, jewelery trade and collection as a curio has severely threatened its survival throughout its range. How encouraging it is to find this in Hantu! If you dive and come across more Black corals in local waters, please email us and send us your pictures!
Slugs and flatworms are always fun to shoot underwater because they are so colourful but also because they just sort of stay still and let you have a go at them!
Finally, everyone’s favourite and a gem in Hantu’s reef - Tigertail seahorses can be spotted on a regular basis. Similar to slugs, they move slowly (infact, seahorses are the slowest fishes in the sea!) and are easily photographed. Because of that, they are also easily collected for the aquarium trade. Like Black coral, all species of seahorses are prohibited from trade because their use in traditional medicines has severely threatened their survival.
Pulau Hantu has 2 varieties of Tigertail seahorse, above is the mottled variety. But whatever colour they feature primarily, all Tigertails have the distinct striped markings at the tip of their tails that give them their name.
Stay tuned to the blog to check out our cool videos from this dive! Coming soon!
Posted: Blog Dives
1
October
2007
Keeping 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.
Many 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.
There 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.
I’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.
A bright sun-shiny day is always good for appreciating Hantu’s amazing diversity of coral.
Tubeworms 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.
Two 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!
This 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.
Finally, 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!
To 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
Posted: News, Blog Dives
