Tuesday, December 18, 2012

Wild abalones at Big Sisters Island!

Unknown to many, we have wild Abalones (Haliotis sp.) in our local waters! And I finally get to find two of them on our weekend trip to Big Sisters Island.

I was surprised to see for myself the two green eye stalks that stick out from beneath the shell of the abalone! They are so cute!

When I attended wedding dinners and casually asked around, many thought that abalones are clams / bivalves. The reality is that abalones are actually marine snails.

The underside of the above abalone looks slightly like a jade. There is a sensory ridge at the margin of their bodies, bearing a series of tentacles.

This is another smaller abalone that I have found with a darker shell. Their shell is loosely coiled with a row of small openings on the left side for respiration.

When overturned, you can witness how they use their muscular foot to flip themselves upright.

The two small wild abalones were first found attached to the underside of rocks. This is how they look like out of water.

Coming back to the trip, the Sargassum seaweed (Sargassum sp.) season is still on where most reefs are ringed by thick blankets of the seaweed.

Here's another look of the reef with lots of seaweed, facing our city centre.

We were fortunate to have the rain stop right after we arrive on the island. That allowed us to explore the shore without having to struggle carrying rain gear.

At some stretches of the shore, thick growths of hard corals can still be seen despite of the thick layers of seaweed.

Seen by Ria on her previous trips, I finally stumbled across this huge anemone which is either a Magnificent sea anemone (Heteractis magnifica) with a pale body column, or a Bubble tip sea anemone (Entacmea quadricolor) with 'deflated' tentacle tips.

At the reef edge, there are a few Bubble tip sea anemones (Entacmea quadricolor) in green.

And there is a tiny Five-spot anemone shrimp (Periclimenes brevicarpalis) living among the tentacles of this anemone!

At the deeper ends, I found this large branch of Stinging hydroids.

For my first time, I found a Winged oyster (Family Pteriidae) attached to the hydroids instead of to sea fans. The shell of this oyster has broad stripes.

The Feather stars (Order Comatulida) are still there though the seaweed bloom made it a little more difficult to find them.

This brown and white version is almost as large as my face! There are some commensals living among the featherstar though it seems almost impossible to document them on photo.

This reefy fish looks like a juvenile version of the Anchor tuskfish (Choerodon anchorago). It was much more steady and less skittish as compared to other fish.

There are lots to find underneath rocks such as this lively Lima file clam (Lima vulgaris) showing its tentacles and siphon in the water. The animal can swim by 'clapping' its valves!

I found a huge flat rock and told Ron that I have a gut feeling that there are surprises beneath it. And true enough we found some awesome finds such as what seems to be a blob of sponge. It is actually a Sponge crab (Family Dromiidae)!

Ron pointed out that this seemingly boring maroon patch is actually a flatworm! Indeed, it moved a little when we were observing it. Unfortunately, its identity is still unknown.

Also on the same rock, there was this black flatworm with yellow and white edges which we don't often see on our shores. It could be the juvenile version of the Orange-white black flatworm.

Looking similar to the previous flatworm, this flatworm that was found crawling among the Sargassum seaweed has its outer edge white in colour. This is the Dawn flatworm (Pseudobiceros uniarborensis).

Also found among the Sargassum seaweed is this Polka-dot jorunna nudibranch (Jorunna funebris) that looks like a white bunny to me.

More sluggish finds on this trip include a pair of these Pimply phyllid nudibranch (Phyllidiella pustulosa).

And also this pair of Black phyllid nudibranch (Phyllidiella nigra). 

What a lovely trip we had with new sightings! I can't wait to revisit Big Sisters Island, preferably when the sargassum season is over. 

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