Semakau North with Giant Clam finds

We were back at Semakau last Sunday and surveyed the northern shore which has thick reefs at the edge. 

A lovely purplish sunrise accompanied the start of our trip. The weather looked good from the eastward direction.

However over at the southwest direction were flashes of lightning that made us felt threatened. Thank God the scary elements went away and didn't hit us.

One of the first finds by Ria would be this huge Cushion star (Culcita novaeguinea)! From far, it may be mistaken as a huge rock or hard coral.

Among the different types of sea anemones sighted, this Leathery sea anemone (Heteractis crispa) is not commonly seen. They have distinctive long tentacles with purplish tips.

Mei Lin found this injured Spotted foot nudibranch (Tayuva lilacina). Not too sure how it lost part of its body.

This cute little purple jellyfish was swimming and pushed by the waves at the reef edge. I'm not sure what is the identity of this fellow.

As usual, the edge is thick with corals of all sorts! The sargassum seaweed is not completely gone and we await their disappearance so that we can check out the corals that were hidden beneath the seaweed bloom.

Here's some underwater shots of the coral garden at the reef slope.

And in some of the shots, you may also catch some photobombing fishes! Haha.

The Smooth leathery soft coral (Sinularia sp.) look like underwater fingers sticking out from beneath.

I can't exactly make out how many Black-margined nudibranchs (Doriprismatica atromarginata) are there in this photo- 2 or 3? :)

It's nice to have good friend Mei Lin (aka our giant clam expert) back on our intertidal surveys. And how nice to find a new Fluted giant clam (Tridacna squamosa) that we have not seen on our previous trips here. This large clam was found right at the edge.

Whereas Mei Lin found a really pretty Burrowing Giant Clam (Tridacna crocea)! It is buried deep in the rock or coral rubble. The clam bores into the hard surface with a combination of chemical and mechanical methods. 

If you zoom in, you can notice that the colours on the mantle are indeed very nice. The giant clam harbours symbiotic zooxanthellae (a kind of single-celled algae) in its fleshy body that also gives the clam its mantle colour. The zooxanthellae produce food through photosynthesis which it shares with the clam.

And before we depart, we had a look at this Fluted giant clam (Tridacna squamosa) that we found on our previous trip. Good to see that it is still there!

Here's an underwater shot which clearly shows the giant clam's siphon which allows it to get food by filtering sea water.

More photos of the trip here: https://www.flickr.com/photos/koksheng/shares/P74hD2