Friday, December 28, 2007

Coral ID Session @ Semakau (II)

Part 2 of coral ID
Christmas day at Pulau Semakau. A bunch of us were out at the intertidals at a field trip; a coral workshop conducted by Jani. Lets see what kind of corals can be found exposed in the intertidals.

A typical Singaporean will asked: "Singapore got corals meh?" At first glance, it does seemed that the land is barren and lifeless.

But nature always has its way of surviving, even when faced under harsh conditions of Singapore corals. Look at the myriad of colors the corals showed!

A brief introduction of corals. They are classified under the phylum Cnidaria and class Anthozoa. Subclass Alcyonaria has feathery tentacles with multiples of 8 (sea fans, sea pens and soft corals); hence its name "Octo". Subclass Zoantharia has mutiples of 6 tentacles hence "hexa". This is further divided into two Orders, Actiniaria which consists of sea anemones and Order Scleractinia, the hard corals, which is our classroom topic for today.

Family Poritidae
Genus Goniopora

This genus has characteristic long polyps and distinguishable from the genus Alveopora which is similar except that each polyp has 24 tentacles (Alveopora has 12). Remember multiples of 6?

Genus Porites
The corallites of this genus is small and depressed in the coral surface. Danwei also commented that its corallite looked somewhat angular although they are in actual fact, circular (probably the shadow it creates.). Its main growth form can be massive or branching.

Side track. Guess what coral is this?

Hint look at the tentacles.

It belongs to a soft coral. Remember that Octocoralli animals has multiples of 8 as well as pinnate (feathery) tentacles?

Family Pocilloporidae
Genus Pocillopora

A rather common coral in Singapore. Exist in branching form. Its corallites has a circular arrangements of heart shaped depressions on it (cant see here of cos). Personally, I have seen alot of small creatures living on the corals themselves, especially porcelain crabs. Theres even bivalves living inside the coralites themselves, saw their hairy legs extending out filter feeding. Wonder how they get in there in the first place.

Family Acroporaidae
Genus Acropora

This is probably the easiest to ID, at least to me. Just look at the tips of the branch and if theres an axial, cup shaped corallite, wala! Not a common coral here as it thrives under pristine waters, however I have seen one large colony in Semakau before, while diving.

Genus Montipora
Not very visible in this picture, but montipora has granulated protrusions from its coenosteum (the coral surface, not the corallite).

Genus Astreopora (Edited: should be Turbinaria)
Not really sure about this but this coral could be under the genus, Astreopora. Astreopora has cup-shaped corallites too and its walls are granulated. (Might be Turbinaria also, not sure ;p)

Family Agariciidae
Genus Pavona (Edited: should be Pssammocora)
This ID is by gut feeling from its form as well as some suggestions from my seniors. In the notes, it stated that this genus's corallites are separated by prominent septo-costae with poorly defined walls.

Family Fungiidae
Genus Heliofungia
A free living coral. While most corals are colonial in nature, Heliofungia is not. Easily distinguishable by its long and large tentacles with white tips.

Genus Fungia
This genus is also solitary and free-living with shorter tentacles and clear septa radiating from the centre

Genus: Herpolitha
Contrary to the two above, Herpolitha corals are colonial and exist in an elongated form. The septa is arranged in a parallel manner but not continuous.

Genus polyphyllia
Also free-living, colonial and elongated, the septa of these corallites radiates out in a fountain like manner.

Family Oculinidae
Genus Galaxea

Another easily identified coral as their corallites are cylindrical with their extended poky septa making it shaped like a star.

Family Pectinidae
Genus Pectinia

Another genus which I'm more familar with, since my other two fellow friends are doing their project on this coral. It will produce alot of mucus when disturbed, very yucky at times when need to handle them. This species is very brittle due to it thin poky septa.

Another species of Pectinia, which danwei, who is working on coral taxonomy, suggested it to be Pectinia alciornis. But he made a comment that corals shouldn't be really classified down to species levels, due to its unconventional evolution.

Side-tracked 2: The evolution of corals

Veron, 1995 first introduced the concept of reticulate evolution in corals. He hypothesized that due to the synchronous mass spawning of many species of corals, hybridization is encouraged. Ocean currents can also carry these larvaes over long distances, thus reintroducing genes to distant population. In times of weak currents and geographical isolation due to movements in land masses, populations are isolated and natural selection occurs, resulting in new species. And so, the cycle goes... In the picture above shows a stretch of how corals evolve, the highly dispersed branches indicate periods of weak currents and isolation, thus many species; the jointed ones indicate periods of strong currents and strong hybrization. There are increasing new evidences to show that this hypothesis might hold true.

Family Mussidae
Genus Symphllia
This family has very long septa teeth and large corallites. This genus has continuous running septa compared to lopbophyilla that runs in loops.

Family Euphyllidae
Genus Euphyllia

This genus is characteristic of their long tentacles. This species above has anchor like tentacle-ends.

While this does not.

Family Faviidae
Genus Oulastrea
The more easily ID favid corals, distinguished by its zebra colors.

Genus Favites

Genus Montastrea
Look at this beautiful fluorescence! To understand more about this phenomenon, have a look at TC's blog.

Genus Goniastrea

Genus Platygyra

Genus Favia
Danwei told me that this golden colored faviid, Favia stelligera is really rare in Singapore, although there are records of it being seen, he himself have not personally saw it in our waters. Woa...

Family Dendrophyllide
Genus Turbinaria
Have more stories to say about this, since I'm working on it on my project. This species is Turbinaria peltata, easily distinguishable from the rest of tubrinaria species due to its large polyps (not seen here). Turbinaria sp. corals are found dominantly in turbid waters, probably due to their ability in heterotrophy being higher their dependence in their zooxanthellae's autotrophy. Whats more, it is known that some corals can actually "feed" on sediments to extract their organic matter, something of an advantage in Singapore waters especially.

It was proved that Turbinaria mesenteria corals can actually change their morphology in response to light with those in shallower waters having highly convoluted shapes as compared their their counterparts having more planar morphology in deeper waters. This serves to increase their light absorption in deeper waters and protect from photo-inhibition in shallower waters. Somehow, I suspect that Turbinaria peltata and others in the same genus also have the same plasticity, having seen them in simpler convulated shapes in shallow waters as in the pict above.

This must be the longest post I had ever done... Phew. Sorry about the lack of explanation in the Family Faviidae, have to ask more on how to ID it first. Thanks Jani again for conducting this amazing workshop, Luan keng for organising it as well as Danwei for the extra interesting details and help in ID.

Thursday, December 27, 2007

Coral ID session @ Semakau (I)

Just the same as Mr Discovery, I am going to split my post into two parts. This intertidal walk was part of a field workshop kindly organised by LK and conducted by Jani. The aim is to learn how to identify the corals exposed at the intertidals. Will do a separate posting for that since there is too much to cover.

For now, lets look at some of other marine life at the exposed shores.

Stichopus ocellatus sea cucumber. Not the most handsome of the cucumbers I know, probably under going puberty with so many pimples ^^ (with white pus inside too, eeww)

Gymnodoris rubropapulosa nudibranch. A cannibalistic slug which feeds on other nudibranchs =s

Egg capsules of squids?

It was a polka dot season. Think I had at least seen ten or more of them today. You can see them in a hive of activity: Like looking for someone to have sex with...

Or looking for its favorite food, the blue sponge. I wonder how it managed to swallow all those spicules (small pointy skeleton) of the sponge. Imagine eating glass...

A docile blue-spotted fan tailed ray lying lazily on the sand. Why do I say docile? Cos it merely finched abit when tidechaser used his chopsticks to sweep the sediment covering its dorsal body.

And the most bizzare feat of all, males having sex without the pleasure. Male octopi merely pass their sperms down its third right arm (usually) and just deposit them into the female's reproductive organ.

Interesting ritual as the male turned into a beautiful zebra stripped pattern (above) a few times and then approached the female..
Inserting its make-shift penis into it.

Sunday, December 23, 2007

A day out at Ubin

Many nature kakis are out here in Ubin today, Luan Keng and the Semakau guides, kok sheng and his team of garang warriors and also Chay hoon at her CJ guide. For me I was invited by Angie to join her church people at an outing at Ubin.

I had first seen the massive grey heron's nesting at Manta's blog. Finally at the chance to see it myself! The majority of the nests are built on the few dead trees in the quarry. What a magnificient sight. There must be at least 50 nests there. (Click on the picture to see the nests!)

At the drinks stall where we stopped by for a sip in the damn hot afternoon, the uncle was drying out theres roots in the sun.

He told us that its some this small herb called "七叶一枝花" which means that the flower comes out after the seventh leaf. The roots apparently has some medicinal value for diabetes and other ailments.

Update from shun deng, the scientific name is "Paris polyphylla". It is a high altitude plant native to China and the Himalayas. The roots has many healing properties: "treatment of poisonous snake bites, boils and ulcers, diphtheria and epidemic Japanese B encephalitis". It also have anti-bacteria and anti-cancerous properties. More in this webby.

It is even an ingredient in the Bo Ying Compound of the 余仁生 stall.

The next stop is at the Chek Jawa boardwalk. At the coral rubble area, look what they found, many adult catfishes! All catfishes have a sharp spine on the dorsal and pectoral fins. Besides giving a painful sting, they may contain venom too. So don't ever handle them with ur hands!

The only coral we can see from the boardwalk, the soft coral Dendronephthya sp. We also saw tons of snapping shrimps, swimming crabs and some carpet anemones and sponges.

At the floating pontoon, we saw two groups of people out there in the intertidals, the Semakau guides and in the picture above, KS and his team.

A magical panoramic view of Chek Jawa from the 7 storey high Jejawi tower.

Just before leaving Ubin, dark clouds looming, signaling a coming storm. Due to massive freshwater input due to Johor flooding, Chek Jawa experienced a mass death last year. How will it fare in this monsoon season? Watchout for KS's Chek Jawa monitoring blog.

Saturday, December 15, 2007

Kranji Trail and Sungei Buloh Walk

Nearly couldnt wakeup today as I was so tired! Thanx to Juan for inviting me to join the trip and CH for organising. Tidechaser, Mantamola, July was also here. Also finally had the chance meet JT, thanks for the drive to Buloh and back :)

We first walked into the Kranji trail. My chosen attire of 3/4 and sandals proved to be a big mistake. Ended up getting bitten all over by red ants...

Basically, today is a day of macro shootings:

A spiny spider, possibly Gasteracactha hasseltii.

A beautiful butterfly with 5 eyes. Waiting for July, the butterfly enthusiast to ID :)

There were many tiny snails and slugs crawling among the leaf blades.

I was mesmerized by this mangrove big-jawed spider! Look at its colorful back...

and front!

Candid shot of the ramblers

We were puzzling what species of lizard this is. But probably a changeable lizard looking at previous photos.

Before ending the trail, a robber fly perching motionlessly for a great shot. Robber flies feed on other flies and insects by injecting digestive enzymes into their victims and sucking up their juices.

And on the Sungei Buloh boardwalk:

An altas moth (Attacus atlas) just sitting next to the board walk! I kinda like moths over butterflies as they are easier to photograph ^^ and they have their wings spread when at rest. They also have super nice and bizzare wings patterns! For the altas moths, they are so named as their wings resembled maps. And they also have the largest wing area among all moths!

Isn't this adorable? A spider carrying its egg sac. Possibly a huntsman spider (family Sparassidae) as suggested by my friend.

This is perhaps the one that generate the most excitement. Jumping spiders (family Salticidae) is the largest family of spiders with over 500 genera and 5000 species. They are active hunters that doesn't spin a web and of cos the most distinguishing feature is that they jump! They also have excellent vision, even able to see UV light! In fact Dr Li Daiqin, the spider expert in NUS had published quite a few papers on the purpose of UV light on these jumping fellows.

This was the first time I seen such a big jumping spider. This was about twice the size of what I seen commonly. Anyway, we were all trying to take pictures of it but it kept jumping on each other's cameras, think only manta's camera din kena. Later after we finished, I din noticed that it had hitched a ride on my back till someone saw it on the next shelter. And all were happily snapping away on my back after that after telling me to freeze there! poor me...

A ton of waders on the mudflats in the abandoned prawn pond.

This was also an interesting sight. A monitor lizard den, or tunnel (not v visible here). Tidechaser and manta had just seen another monitor slipped into before this too.

Pretty pink eggs of the apple snail deposited on the water hyacinth.

Its been quite awhile since I been out on a leisure walk. Nice day out in the sun and basking with nature. =)
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