Monday, June 02, 2008

Stars and Spikes at Changi

Went to Changi Beach several times last month, and thought I'll just highlight some of my favourite sightings here :)

Knobbly sea star, Protoreaster nodosus
Perhaps the most exciting finds during the trips were the knobbly sea stars (Protoreaster nodosus) that come in various sizes. It's as if you can map out the growth process. The one above is about the size of a 50 cent coin. While it's not very visible in the photo above, we could already see little knobs on its top surface when we were there.

Knobbly sea star, Protoreaster nodosus
This one was a little bigger than a 50 cent coin (will estimate it to be about 1cm wider), and we could already see the knobs rather clearly.

Horned sea star, Protoreaster nodosus
This one was much larger than the two above, about the width of two 50 cent coins. Some how the greenish tint doesn't show in the photo above, probably due to the direct sunlight falling on it's top surface. But when we were there, we could clearly see a bit of greenish tint on its surface, though it's certainly not as green as the two smaller ones above.

Seems like so far the little knobblies we've been seeing at Changi started off as little green stars. Wonder if that's the case in the other places where they can be found...

Biscuit sea star, Goniodiscaster scaber, starfish
Other star finds at Changi included several biscuit sea stars (Goniodiscaster scaber), which looked like little star-shaped biscuit (a bit of imagination required).

Crown sea star, Asterina coronata
But one of the stars that really rocked us was this pretty orange-coloured rock star (Asterina coronata).

Rock star, Asterina coronata
This is how the usual rock stars look like. They are usually found in a rocky shore habitat.

Brittle star
We also saw several brittle stars stranded on the sand due to the low tide.

Salmacis sea urchin
Apart from the starry ones, we found lots of the spiky ones too - the sea urchins. The above is a Salmacis sea urchin (Salmacis sp.). They appear to be seasonally and once in a while, we'll see lot's of them on our northern shores.

Little black sea urchins, probably Temnopleurus sp.
Also seasonally abundant are these little black sea urchins (probably Temnopleurus sp.).

Pencil sea urchin, Prionocidaris sp.
We also found this pencil sea urchin (Prionocidaris sp.) in an upside-down position, with its upper spines stuck in the soft sand. Guess it's probably washed to this position by the waves.

Others than the stars and spikes, we found many other interesting animals, such as the little nudibranch above. Have no idea what nudibranch that is though.

Stichodactyla haddoni, carpet sea anemone
While Haddon's carpet anemones (Stichodactyla haddoni) were rather common at Changi, it's becoming rather uncommon to see one bigger than my face, like the one above. It's just unfortunate that there are poachers who go around collecting the bigger ones...

Thunder crabs, Myomenippe hardwickii
On of of the mornings, we found several thunder crabs (Myomenippe hardwickii) forming little circles, and some of them (females) were in the upside-down position. Could it be that they had just finished mating?

Coastal horseshoe crabs, Tachypleus gigas
We were rather fortunate to find a pair of coastal horseshoe crabs (Tachypleus gigas) too! Note that while one was on top of the other, they were not exactly mating though. Horseshoe crabs practise external fertilisation, and the female will usually carry the male around until she's ready to lay eggs, usually during high tide in a pit she created, and the male will then come down to spread its sperm over the eggs. They may return again during the next high tide and the female can lay up to several thousand eggs!

Well, that's all for now. Hopefully can find time again these few days to post some of the other trips I made last month :P

No comments: