Sunday, November 30, 2008

Dragonflies at Ang Mo Kio Lotus Pond

It's been a while since I last visited the lotus pond at Ang Mo Kio. When I went there in February this year, XF grumbled that I didn't meet up with him even though it's just opposite his house, so this time round I decided to drag him along as I explored the area.

Somehow the lotuses did not seem to be doing very well though, and most of them seemed to be dying. Not sure if it's a seasonal thing.

But as usual, there were lots of dragonflies!

Dragonfly, Acisoma panorpoides
Here's a male Acisoma panorpoides, which is quite common in Singapore. I especially like the colour of its compound eyes - don't the eyes look like 2 little pieces of turquoise?

Dragonfly, Brachydiplax chalybea
I often had problem identifying this blue dragonfly, which could be a Aethriamanta gracilis or Brachydiplax chalybea. I assume its the former in this case though, since the dragonfly is not very big, and the latter is supposed to be bigger.

Dragonfly, Orthetrum glaucum
I was pleasantly surprised to see this big blue dragonfly, probably a Orthetrum glaucum.

Dragonfly, Rhodothemis rufa
Other than the blue dragonflies, we saw several red ones too. Had thought the above is a Crocothemis servilia, but on checking again, thought the red is not as bright as the usual C. servilia that I've seen, and it doesn't have a black line on its abdomen, so it's probably a Rhodothemis rufa instead.

Dragonfly, Orthetrum testaceum
Here's another red dragonfly. Looks rather similar to the previous one, but I think it is probably a Orthetrum testaceum as the colour of the eyes looks different. Note sure if I'm right though.

Dragonfly, Orthetrum chrysis
This one looks like a Orthetrum chrysis to me.

Dragonfly, Neurothemis fluctuans
And of course, we also spotted this very common dragonfly, Neurothemis fluctuans.

Apart from the dragonflies, there were several damselflies too. The above is one of them, but I won't attempt to try to identify its species, since frankly speaking, many of them just look too similar to me.

Batik golden web spider (Nephila antipodiana)
With so many dragonflies and damselflies, there are some of their predators around too, such as the batik golden web spider (Nephila antipodiana).

Green-crested lizard (Bronchocela cristatella)
There were also several lizards around, including this green-crested lizard (Bronchocela cristatella). It is now rather uncommon to see these lizards, as they were out-competed by the introduced changeable lizard.

It was rather amazing when you think about it, that there were still so many little pockets of nature among the concrete jungles of Singapore. Just a short walk around a little pond in the middle of the neighbourhood, and I was rewarded with so many interesting wildlife!

Semakau Walk on 27 Nov 2008

It's a low spring tide day again! This time round, we were bringing about 60 secondary school students who were also volunteers for Project Semakau. This trip would give them a good overview of some of the interesting marine life that could be found on the island, and how to identify them. With me was a group of students from Dunman High, and our group name was Octopus.

Rhizophora apiculata
This was one of the mangrove trees at the exit of the secondary forest, probably a bakau minyak (Rhizophora apiculata). It has red stipules, and interestingly, I notice that the seedling had a red collar. Read from one of the online mangrove guide that mature propagules of Rhizophora apiculata has a red collar. This was something that I had not noticed before.

Brittle star
The students found this brittle star, which I have not seen before. Brittle stars can usually be identified by the presence of a circular central disc with 5 long arms attached to the disc. They move by swinging their arms, instead of sliding across the substrate with the tube feet found on the underside of their sea star cousins.

Starfish (Archaster typicus)
At the edge of the seagrass meadow, we found a population of sand sifting sea star (Archaster typicus). These sea stars are able to burrow into the sand to seek food (they feed on tiny organic particles) and also to escape from predators. Like other sea stars, they move with their tube feed on their underside, sliding over the surface of the substrate.

Sandfish sea cucumber (Holothuria scabra)
Another sandy shore dweller was this sandfish sea cucumber (Holothuria scabra). It too can burrow, feeding on the detritus (tiny organic particles) in the substrate. This sea cucumber is usually brownish in colour, sometimes with darker stripes on the top surface, making them look like "garlic breads", which gave it is other common name - garlic bread sea cucumber.

As we headed towards the coral rubble area, we were pleasantly surprised to see this unidentified sea star again, which looked like a combination of both the knobbly sea star and cushion star.

Hairy crab (Pilumnus vespertilio)
Among the coral rubble were lots of hairy crabs (Pilumnus vespertilio). The tiny hair on its exoskeleton traps sand and mud, allowing it to blend nicely into its surrounding.

Noble volute (Cymbiola nobilis)
We had been seeing several noble volutes (Cymbiola nobilis) lately, and it was no exception for this trip. This juvenile noble volute's shell was still very smooth and pretty, without any algae growing over the surface. It has a very pretty body with lots of bright orange spots on a black background.

Dragonfish sea cucumber (Stichopus horrens)
In one of the tidal pools, we found this sea cucumber, which so far we have been identifying it as a dragonfish sea cucumber (Stichopus horrens). It is usually yellowish brown in colour, with a thorny appearance. Will probably need to find an expert to confirm its identity.

Spider conch (Lambis lambis)
The spider conch (Lambis lambis) was regularly sighted in the coral rubble area, and has several protruding spines curving in the same way. Conches have two little eyes on a stalk each, allowing them to keep a lookout for any threats in the surrounding before they exposed their body to feed or move around.

Sunflower mushroom coral (Heliofungia actiniformis)
In one of the tidal pools nearer to the reef crest, we found a sunflower mushroom coral (Heliofungia actiniformis). With its long tentacles, this coral is often mistaken to be a sea anemone. The long tentacles have a white tip each, and the hard skeleton of the coral is round-shaped and not attached to the substrate.

Knobbly sea star (Protoreaster nodosus)
We saw 2 knobbly sea stars (Protoreaster nodosus). The one above looked like one of those juvenile knobblies which we saw during the Project Semakau launch.

Starfish, Knobbly sea star (Protoreaster nodosus
This is one of the adult knobblies which we regularly see during our walks.

Table coral (Acropora sp.)
The table coral (Acropora sp.) is very common in the region in areas with clear water, as this coral requires lots of sunlight to do well. Acropora corals in Semakau's intertidal area are usually small colonies, and both branching and tabular forms have been seen.

Synaptid sea cucumber
Two long synaptid sea cucumbers were spotted today - one in the seagrass meadow, and the other in the coral rubble area near the reef crest. This is a very long sea cucumber, and we have seen those growing up to 2m long.

Funeral nudibranch (Jorunna funebris)
The funeral nudibranch (Jorunna funebris) is one of the most common nudibranch on Semakau. the term "nudibranch" means "naked gills", refering to the exposed gills found on the back of most species.

Stonefish sea cucumber (Actinopyga lecanora)
This is probably the stonefish sea cucumber (Actinopyga lecanora). We have seen many variations of coloration for this species, ranging from completely brown, light brown with dark brown patches, light brown with dark brown spots etc. The area around its back end is usually lighter in colour, and has 5 anal teeth.

Flatworm (Acanthozoon sp.)
There were lots of flatworms in the coral rubble area, though most of them were this Acanthozoon sp. Flatworms are very, very flat, and are usually ovoid in shape. They also have a pair of pseudotentacles at their front ends. Some of the bigger species are able to swim by flapping the sides of their bodies.

Hell's fire sea anemone (Actinodendron sp.)
As we were heading back towards the secondary forest, I found this hell's fire sea anemone (probably Actinodendron sp.) in a small tidal pool. It has lots of branch-like tentacles which can give a nasty sting.

Here's a shot of the students in my group, crossing the seagrass meadow.

Sunset at Semakau is always so pretty...

I certainly hope that Project Semakau will be a success, and we can eventually turn this into a protected marine park! :)

Sunday, November 23, 2008

Seeking Dragonflies at Marina East

It's been a long time since I last went to Marina East, and thus today I decided to join LK and Tang for their dragonfly survey there.

Dragonflies are among my favourite subjects for photography, as the can look really good on photos. It's not always easy to photograph them though, as they are usually very alert. That's because they have very large compound eyes and have very good vision.

Dragonfly compound eyes and ommatidia
Looking at the eyes closely, you will see lots of ommatidia, which are basically visual units consisting of a lens system and a group of light sensitive cells. Each eye may consist up to 30,000 ommatidia, which together form a mosaic image in the dragonfly's brain.

Nonetheless, it's still much easier to take photos of dragonflies compared to butterflies, which hardly stop. Here are some of the dragonflies we saw and I managed to capture on photo :P

Dragonfly (Crocothemis servilia)
A male Crocothemis servilia. Commonly seen in Singapore, they seem to prefer disturbed open habitats.

Dragonfly (Crocothemis servilia)
"What you looking at?" - Managed to capture this photo just as this female Crocothemis servilia turned its head.

Dragonfly (Acisoma panorpoides)
A male Acisoma panorpoides. The females are yellow in colour.

Dragonfly (Neurothemis fluctuans)
An immature male Neurothemis fluctuans. This is one of the most common, if not the most common, dragonflies in Singapore.

Dragonfly (Neurothemis fluctuans)
The mature male Neurothemis fluctuans is dark red in colour.

Dragonfly (Rhyothemis phyllis)
A Rhyothemis phyllis.

We saw this huge dragonfly (Tramea transmarina) hunting a slightly smaller dragonfly, a Orthetrum sabina. Didn't managed to get a photo of the latter though.

Dragonfly (Brachydiplax chalybea)
This is probably a Brachydiplax chalybea.

Dragonfly (Orthetrum luzonicum)
This is probably a Diplacodes trivialis.

All in all, we saw lots of dragonflies of different species today, but sadly, we also didn't managed to find some species which we saw during our previous trips. The development work in the surrounding area probably caused the disappearance of the more sensitive species.

Hopefully, the next time I come here again, things would have improved :(

Friday, November 21, 2008

Pasir Ris Beach

Decided to help KS with his sea star research at Pasir Ris last Monday since I had not helped him for quite a while, and also understood that it's his exam period at the moment, and most of his friends were not able to find time to help him.

Sand stars (Astropecten sp.)
Pasir Ris had a huge population of sand stars (Astropecten sp.). There were hundreds, if not thousands, of these little sea stars lying on the sand when we arrived.

Sand star (Astropecten sp.)
Most of them had the usual five arms, but we found one with only four arms.

After finding the spot with the most sand stars, we starting helping KS with his project. It was a rather tedious job actually, but that didn't stop us from taking photos other other interesting animals we saw them :)

Rock stars (Asterina coronata)
Other than the sand stars, we also saw several rock stars (Asterina coronata), and among them was another surprise find - one with six arms instead of the usual five arms!

Brittle Star
Another star we saw was this brittle star. Can't really remember if I've seen something like this before. It burrowed quickly into the sand as we were taking photos of it.

Bobtail squid
Enough about echnioderms, this little bobtail squid (Order Sepiolida) must be the cutest find of the day! This little cephalopod is said to be more closely related to the cuttlefish than true squids.

Bobtail squid
After a while, it tried to burrow into the sand. So cute right? :P

Orange mud crab (Scylla olivacea)
Most Singaporeans are familiar with the dish "Chilli Crab", but many probably do not know that the orange mud crab (Scylla olivacea), which is the mud crab often used in this dish, can also be found in Singapore.

Elbow crab
Elbow crabs (Family Parthenopidae) camouflage themselves very well with the surrounding mud and sand, and sometimes it can be quite difficult to spot them, even though they are quite common on our shores. They got their name from the long pincers potruding far out from its body.

Moon crab (Ashtoret lunaris)
Like most other sandy beaches in Singapore, moon crabs (Ashtoret lunaris) were rather common at Pasir Ris. Not really sure how did the one above got the seaweed stuck to the sides of its eye stalks.

This shrimp which I have no idea of the exact ID was particularly camera friendly, and hardly moved until I finished taking the photos I wanted.

These two seahares (Suborder Aplysiomorpha) looked like they were stranded together on the shore when the tide receded. Wonder if they were doing anything to prepare for the next generation when that happened :P

Sea pen
Several stranded sea pens (Order Pennatulacea) were also found on the sand.

It was already rather late and the tide was quite high by the time we finished out work, and we also didn't quite have the energy to explore further to seek for more intertidal life. But still, it's a nice change once in a while to help out with research work rather than doing guiding or leisure trips :)