hermit crab @ terumbu raya 09Feb2009

hermit crab 1 @ terumbu raya 09Feb2009 from BeachBum on Vimeo.


hermit crab 2 @ terumbu raya 09Feb2009 from BeachBum on Vimeo.


hermit crab 3 @ terumbu raya 09Feb2009 from BeachBum on Vimeo.


hermit crab 4 @ terumbu raya 09Feb2009 from BeachBum on Vimeo.


hermit crab 5 @ terumbu raya 09Feb2009 from BeachBum on Vimeo.

The movement of this hermit crab caught my eye as I scanned the rubble. I thought i saw a rock move and went over to investigate. This was a rather large hairy hermit crab...not commonly seen on our shores...and more rarely seen on submerged reefs like Terumbu Raya.

It seemed at home on the 'dusty' sand. and went on picking at the sand and sargassum for morsels of food. Video 4 shows it's ability to right itself up. Almost the whole body comes out of the protective shell (a snail used to formerly inhabit it) and the crabs pulls itself the preferred way up. Strong wave action can frequently turn the shells and it is important for hermit crabs to be able to set themselves under cover soon enough.

For more on hermit crabs see :-
http://www.wildsingapore.com/wildfacts/crustacea/anomurafi.htm
http://www.wildsingapore.com/wildfacts/crustacea/othercrust/anomura/hermit/veryhairy.htm

See also http://nakedhermitcrabs.blogspot.com/ !

nemos & giant carpet anemone @ t raya 09Feb2009

nemos & giant carpet anemone @ t raya 09Feb009 from BeachBum on Vimeo.
This medium-sized giant carpet anemone was in a shallow pool with hardly about 5cm of water. I saw a large nemo dive from below the outer folds into a corner of an adjacent rock. It was a small corner and so the nemo stuck out visibly.

On a second look, i realised there was a smaller nemo in the middle of the anemone. It was just at the surface of the water nestled in the anemone and it seemed like it was gasping for air lying on it's side. It must have been hiding in the anemone's inner folds before running out of air and causing it to be near the water surface. Easy prey for a wandering bird. After flapping around a bit, it disappeared into the inner folds safe away from sight.

Find out more about :
Nemos : http://www.wildsingapore.com/wildfacts/vertebrates/fish/pomacentridae/ocellaris.htm
Giant Carpet Anemones : http://www.wildsingapore.com/wildfacts/cnidaria/actiniaria/gigantea.htm

octopus @ terumbu raya 09Feb2009

octopus @ terumbu raya 09Feb2009 from BeachBum on Vimeo.
This small octopus shot out from below a clump of sargassum and swam towards a rock. It's colour effortlessly changed from a dark red to a pale mottled pattern to fit the rock it swam to. It quickly slid below the rock to hide.

My guess is that the one observed in the clip was a two-spot octopus.

Read more about the types of Singapore's octopus here :
http://www.wildsingapore.com/wildfacts/mollusca/cephalopoda/twospot.htm
http://www.wildsingapore.com/wildfacts/mollusca/cephalopoda/smooth.htm
http://www.wildsingapore.com/wildfacts/mollusca/cephalopoda/octopusnoid.htm

chequered cardinals @ terumbu raya 09Feb2009

chequered cardinals @ terumbu raya 09Feb2009 from BeachBum on Vimeo.

At low tide, all the small fish take to hiding in the remaining shallow pools. With a dense growth of sargassum algae, the fish have a good amount of hiding places. This group of cardinals were swimming from pool to pool. Fish are difficult to video as they tend to be more sensitive to movements. However, these cardinals co-operated just fine.

Read more about the chequered cardinals here :
http://www.wildsingapore.com/wildfacts/vertebrates/fish/apogonidae/margaritophorus.htm
http://habitatnews.nus.edu.sg/guidebooks/marinefish/text/275.htm

spooked halfbeak @ terumbu raya 09Feb2009

spooked halfbeak @ terumbu raya 09Feb2009 from BeachBum on Vimeo.

There was a flurry of splashing in a pool behind me and when I turned around, there was a fish jumping across the shallow pools and on to the sand. It was obviously trying to reach a deep pool with sufficient water but it was out of luck as the whole area within a few metres was all devoid of any significant water holes.

I waited for the halfbeak to quieten down before gently grabbing in the palm of my hand and carrying it to a deep pool closer where there was a rocky overhang for it to take shelter away from the passing gaze from the fish eating birds overhead.

Find out more about halfbeaks here :
http://www.wildsingapore.com/wildfacts/vertebrates/fish/fishfi09.htm

purple&pink 'wiggly star' anemone @ terumbu raya 09Feb2009

pink&purple 'wiggly star' anemone @ t. raya 09Feb2009 from BeachBum on Vimeo.
Here is a short clip on the pink-purple 'wiggly star' anemone from Terumbu Raya. It was in less than 10cm of water in a shallow pool.

The tentacles were purple with pink tips except for the vertical tentacles which were all brown. The diameter of this specimen was about 4 cm across.

Read more about it here :
http://www.wildsingapore.com/wildfacts/cnidaria/actiniaria/star.htm

More about the trip here :
http://wildshores.blogspot.com/2009/02/reefs-of-raya.html
http://wildshores.blogspot.com/2009/02/maiden-trip-to-terumbu-raya.html

strange anemone @ terumbu raya 09Feb2009

strange anemone @ terumbu raya 09Feb2009 from BeachBum on Vimeo.
Came across this strange anemone (most of them are new to me anyway!).
Appearing black from far away...it was actually closer to a very dark reddish brown from up close.

my foot, being in the wrong place, was responsible for mucking up the water coming into the pool which contained the anemone...this is evident from all the particles floating into the scene. I decided to abandon the anemone for the time being and looked around for something to mark the spot. The good thing about submerged reefs like Terumbu Raya is that floating rubbish tends to float on with each high tide. There was almost nothing to be seen except for a coke can which had got stuck in the mud. I emptied it and placed in on a nearby rock and moved on.

Later Stephen came by and said he had seen the anemone too but that it had disappreared into a hole. When I went back to the coke can...the anemone was nowhere to be seen....all that remained was a hole in the sand. And it was about time to leave the terumbu.

More about this anemone here :
http://wildshores.blogspot.com/2009/02/strange-anemone-from-pulau-semakau.html

Turns out that this is Actinostephanus haeckeli and it is "known from the western rim of the Pacific."

Cool! that Singapore has them too!

More about the trip here :
http://wildshores.blogspot.com/2009/02/reefs-of-raya.html
http://wildshores.blogspot.com/2009/02/maiden-trip-to-terumbu-raya.html