Dang, it’s been a long while (a month or so, I must say) since I last updated my blog with anything new. Procrastination has been keeping me company all this while and I must say, it’s time to show this fellow to the door. =) Though this site seems to have amassed a large amount of dust bunnies; my life, on the other hand, has been pretty much keeping me on my toes (fingers too!). All the projects and deadlines have been making me real hungry, and lately, cakes have been number 1 on my must-have craving’s list. So here I am, keeping my fingers tap-dancing atop the keyboard while waiting for my cakes to thaw (the 20 minutes should be up any moment now). But before that, let’s take a look at what my trip last month to Sekudu Island had in store for yours truly. ^^
(left): Biscuit sea-star (Gonodiscaster scaber) – aboral side.
Aboral basically means ‘away from (ab-) mouth (-oral)’. The mouth of a sea-star, like so, is situated beneath. According to the “A Guide to Sea Stars and Other Echinoderms of Singapore”, the Biscuit’s surface is sandy brown with black markings scattered in areas between the arms (otherwise known as the interradii). Also, as you can see from this Biscuit, it also has a dense covering of light-coloured, rounded projections. Something like a sprinkle of finely-chopped light brown hazelnuts atop a star-shaped cookie, yes?
(right): Biscuit sea-star (Gonodiscaster scaber) – oral side.
Turn it around, and you’ll see that surrounding its mouth (at the interradii area) is the hue of a dull yellow before becoming white at the edges.
Here’s another Biscuit with its oral side labelled to give readers a clearer gist of what’s what and where’s where before a horde of question marks start having a mass demo in the head (just kidding~). So as mentioned, on the oral side, we have the mouth (right at the center) that’s surrounded by five interradii (coloured yellow) and also five rows of ambulacral grooves. Running along the grooves are numerous squiggly and squirming tube feet. For identification purposes, the Biscuit’s pigmentation around the mouth and partway along either side of the ambulacral grooves is a shade of purple.
(left): Orange-tipped sea-star (Gymnanthenea laevis) – aboral side
With tips a bright orange, it’s obvious why this sea-star has its common name as such. The five arms, like the Biscuit, are blunt. But unlike that ‘cookie’, the Orange-tipped has slightly upturned tips. Usually, a sea-star will curl its tips when it’s out of the water for too long, but I guess it’s different for this particular fellow, even when it’s immersed in salty H2O. Other notable features for rough identification is the obvious spine-like projections on the surface (center, and sometimes at its adjacent).
(right): Orange-tipped sea-star (Gymnanthenea laevis) – oral side
Unlike the squeaky clean oral side of the Biscuit, the Orange-tipped has its own a-scattered with dark flecks. Also to differentiate between the Biscuit and the Gymnanthenea, one other prominent feature that can be used is the pedicellariae that’s abundant on the oral surface of the latter.
Pedi-what, you say?? Pedicellariae (pronounced ‘pear-duh-sur-lair-ee-uh’) is the tiny pincer-like structures that’s common on the surface of starfish (sea urchins too!) used for self-grooming and capturing tiny prey. Talk about killing 2 birds with 1 stone. =) And courtesy from the photographer herself *ahem*, we have a close-up shot on the pedicellariae of the Orange-tipped. So next time, when a Biscuit and an Orange-tipped decides to pull a trick and play the ‘Guess who’ game, just flip over the sea-stars and look for huge, bivalved pedicellariae (or the lack of it). Easy peasy. :)
Next up on the ‘menu’ of Mother Nature’s own patisserie is the Cake Sea Star (Anthenea aspera). Just like a cupcake, the upper surface (or the aboral side) of the Cake is generally slightly convex while the bottom is flat. Similar to the Orange-tipped, the arm tips are slightly upturned. Compared to the no-pedicellariae evident Biscuit and the oral-pedicellariae-d Orange-tipped, the Cake has those structures prominent on both sides of its surface (right picture shows aboral surface).
Though colours and shape seem candy-licious, it’s advisable to think twice (or thrice) before you sink your teeth into any of these echinoderms. Though there are vendors in the streets of China selling starfish like satay, it’s far from being one. Yes, not only is it meat-less (sea-stars have an external body wall of calcite), the body wall of sea-stars (asteroids especially, like the one in the videos below) are chock-full of toxic biochemicals [1]. But true to our nothing-is-inedible nature, the videos below show us why Homo sapiens are kings at the top (albeit precarious) of the food-chain. After all, everything can be consumed at least once. It could be either a gastronomical experience or its bye-bye and off to the pearly gates you go! Wonder what were the fates of the people that ate the fried sea-stars though…
Here are two Cakes (Anthenea aspera) with both a specific hue of their own. If you scrutinize the left picture, you will some tube-feet sticking out from the tips of the arms (nearest to the ruler) of the red-speckled, brown-edged sea-star (left). =)
A look on the oral side of both Cakes (Anthenea aspera). They seem fairly plain compared to the dark-flecked Orange-tipped and the yellow-purple pigmented Biscuit. And as stated above, the oral side, like the aboral side, are strewn aplenty with the sea-stars own grooming device.
Pedicellariae on the aboral side of the red-speckled, brown-edged Cake Sea Star (Anthenea aspera).
The orange Cake Sea Star (Anthenea aspera) has a slightly different version compared to the previous, but they are rather prominent just the same.
Protoreaster nodosus, otherwise more fondly known as the Chocolate Chip Sea Star, no prizes for guessing why. The ones we bumped into at Pulau Sekudu were freaking huge, with a single arm as long as my 15cm ruler! Skimming over coral-reef substrate or meadows of seagrass, the Chocolate Chip satisfies its appetite with the minute organisms that made those areas home sweet home. To feed, the sea star (like many others except a couple) will turn its stomach inside-out over its food. Breaking its food down via the digestive liquid that it secretes, the nutrients are then only absorbed.
Another find of the day was the Brittle star (Ophiothrix sp.) and boy, was it a first of me to see a whole one. Usually, the most I would be able to see is just one limb (or two if it was feeling generous) before it disappears into the dark shadows of a sponge crevice. >_< Even at the gentlest handling, the long and gangly-armed Brittle Star will not hesitate to say sayonara to its one of its limb in attempt to distract any potential predators, kinda like a lizard I must say.
Astropecten sp. or Spiny Sand Star is one sea-star that has rows of spines extending along the edges to give it a comb-like appearance. Astropectinids, unlike the Biscuit, Orange-tipped, Cake, Chocolate Chip etc (we think with our tummies indeed), have the ability to ingest their food whole instead of turning their stomach inside-out to digest their prey. Now a question to ponder upon a rainy day: which came first on the evolution track, sea-stars that ingest internally or the ones that thrust their tummies out? And why the need for such an evolution?
(Left): Apart from the Astropectinids, luidiids like the 8-armed Sand Star (Luidia maculata) also share the ability to ingest their food externally. This critter here was my first Luidia and man, was it the cutest little thing I have ever seen. This lil’ luidiid was so small that it’s only one fifth of my palm, a baby still as indicated by its growth (photo credits to KS).
(Right): And yet another baby which we crossed paths with – the Rock Star (Asterina coronata).
And as we took another step, more babies came into view. This time round, a juvenile Cake Star (left) and a young Biscuit Star (right). Just above the Biscuit is a pretty in pink sand dollar (Peronella lesueuri).
Again another first, and I should be counting my lucky stars since these beauties are not common in Singapore waters. The near-circular and hard protective shell of the sand dollar is the one that’s coloured a cotton-candy pink while its underside (right) is a soft peach. The ‘petals’ (left) as can be seen, extend only halfway out to the edge of the disc.
(left): Though not as gorgeous as the Peronella, the Ball Sea Cucumber (Phyllophorus sp.) is more abundant and is a rather common sight at Pulau Sekudu.
(right): Sandfish Sea Cucumber (Holothuria scabra) – a delicacy at many Chinese restaurants, was also spotted. Even so, it needs to be processed and cleaned off its toxins before it can be served on a platter to the customer.
And last but not least, I present the Thorny Sea Cucumber (Colochirus quadrangularis). Cut it cross-section (or in half), it will look square or quadrangular. Cucumbers like this one are seasonal – one moment there may be none of them and then at other times of the month, a baby boom occurs and the beaches of Changi and Ubin Island will be blanketed by pink juveniles.
In case anyone was wondering (otherwise the wall would do just as well), Pulau Sekudu or the Frog Island was known as such because legend has it that three animals from Singapore - a pig, an elephant and a frog - had a challenge to see who could reach the shore of Johor first. Whichever animal failed to reach the shore would be turned into rock. All three creatures had difficulties swimming, and while the frog turned into Pulau Sekudu, both the pig and the elephant turned into a larger island, Pulau Ubin [2]. For animals so small, they turned into something relatively large. Either they were deities looking for a lil’ fun without having to use their magical powers or they were ginormous creatures to start with… either way, there’s something wrong with the picture here (and I don’t mean the one above.. :P)
References:
1. http://echinoblog.blogspot.com/2008/04/people-eating-starfish.html
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