sgbeachbum: Pulau Hantu walkabout ~ 22Jan2011

It was a dusky sunset evening...

dusky sunset 22Jan2011 from BeachBum on Vimeo.

List of things seen :-

Pygmy Squid : this little guy was floating away from any vegetation cover and it had a whitish attachment on its rear...not sure what that was. The pigment changes from pale to deep purple were instantaneous! Amazing!

pygmy squid 22Jan2011 from SgBeachBum on Vimeo.
Read more about Pygmy squids here : http://www.wildsingapore.com/wildfacts/mollusca/cephalopoda/pygmy.htm

transparent Enhalus ghost slug : this was about 0.7mm long sliding about on an Enhalus leaf. The white stuff could be ingested detritus ready to become poo. The leaf blade was clear of any sediments or encrustations. The slug was performing a vacuum cleaning service!

transparent ghost slug 22Jan2011 from SgBeachBum on Vimeo.
Read more about it here : http://www.wildsingapore.com/wildfacts/mollusca/slugs/anaspidae/seagrass.htm

Swimming crabs
There were quite a few swimming crabs out for dinner. These crabs are named such because their last pair of legs have been flattened to greatly facilitate moving around under water. Generally carnivorous, eating anything that comes within grabbing distance of their sharp claws, they would also scavenge from the reef floor. These seemed to be the blue-spined variety. but many of the swimming crabs look very similar with slight variations in colour tone and patterns on their carapace.

swimming reef crabs 22Jan2011 from SgBeachBum on Vimeo.

Further reading :
Singapore's swimming crabs : http://www.wildsingapore.com/wildfacts/crustacea/crab/portunidae/portunidae.htm
How to tell our swimming crabs apart : http://www.wildsingapore.com/wildfacts/crustacea/crab/portunidae/cfportunidae.htm
More pics on the blue-spined swimming crab :
http://www.wildsingapore.com/wildfacts/crustacea/crab/portunidae/bluespined.htm

Cuttlefish (banded 3-spot) : This little guy was about 1.5cm long and showed fantastic camouflage abilities by moving to below an Enhalus Leaf and appearing to be a decaying leaf sheath nestled at the bottom of the plant. Notice how it uses it's 'legs' to hold itself in that same position.

cuttlefish 22Jan2011 from SgBeachBum on Vimeo.
Read more about it here :
http://www.wildsingapore.com/wildfacts/mollusca/cephalopoda/threespot.htm

Sponge brittlestars
Read more about it here : http://www.wildsingapore.com/wildfacts/echinodermata/ophiuroidea/tinysponge.htm

Peacock anemone
Read more about it here : http://www.wildsingapore.com/wildfacts/cnidaria/others/ceriantharia/ceriantharia.htm

peacock anemone 22Jan2011 from BeachBum on Vimeo.

various hard corals

mysterious black spot on hard coral : which seemed to be oozing out a white 'poo' from within. Is this some sort of anal aperture for hard corals?

coral black spot 22Jan2011 from BeachBum on Vimeo.

snapping shrimp : http://www.wildsingapore.com/wildfacts/crustacea/othercrust/shrimp/alpheidae.htm

ghostly shrimp fry : Huge patches of the shore were covered with an incredible number of tiny transparent shrimp fry. It's easy to see how so many of them will become dinner for another larger organism supporting the web of life. The fry did seem to be attracted to light and congregated towards light from a torch.

ghostly shrimp fry 22Jan2011 from BeachBum on Vimeo.

common sandstars

flatfish (Ovate sole) :

ovate solefish 22Jan2011 from SgBeachBum on Vimeo.
Read more about it here :
http://www.wildsingapore.com/wildfacts/vertebrates/fish/soleidae/ovata.htm

Broadnosed halfbeak : It was about 4cm long and was hiding amongst the sargassum seaweed. It does not do a very good job at it as it has a bright white spot near its dorsal fin.

broadnosed halfbeak 22Jan2011 from BeachBum on Vimeo.
Read more about it here :

http://www.wildsingapore.com/wildfacts/vertebrates/fish/hemiramphidae/broadnose.htm

Octopus : Came across this Octopus heading back to its lair in the seawall. The tide had gone out pretty much and it had to do some quick gymnastics over the rocks to get into its hiding place. Note how the octopus uses its arms to 'see' where it should go before it decides. And also the amazing instantaneous colour changes!