Saving Changi Crabs

On this very morning, something upsetting happened at one of the beaches in Changi. Just as my friends and I were about to end our intertidal survey, we found a 50m driftnet. It is unsure how long the driftnet had been laid.

Looking at the driftnet after we brought it in in sections.
[Photo from Project Driftnet]

It took us plenty of patience and skills to untangle and cut free the trapped marine animals from the net.

Working hard and carefully to free the tangled flower crabs from the net.
[Photo from Project Driftnet]

In total, we counted 40 flower crabs, 1 stone crab, 1 stingray, 1 horseshoe crab, 1 flounder and some decomposed fish.
I tried to remove a very agitated stone crab, probably stressed from being trapped in the net and unable to free itself. It took me many attempts to cut free the crab before my hands were unable to hold its powerful repel.

Me attempting to cut free the stone crab.
[Photo by James Chua]

Unfortunately, I could not remove all of the nets tangled in the crab before it escaped.

Changi beach is not all about driftnets and trapped, dying animals. The intertidal shore is full of life too. On the rocks, there are numerous lined bead anemone (Diadumene lineata) lining among various nook and cranny on the rock surface.

Lined bead anemone

In the sheen deep part of the shore, there were spare distribution of these colourful cerianthids in their bright neon colours. They are also known as peacock anemones but they are not true anemones.

Cerianthid (Peacock anemone)

On the water surface, a broad-nosed halfbeak swam by but was rather shy and quick to swim away after this shot.

Broad-nosed halfbeak

The seagrass meadow is not all that dull and boring. If you stop and take a closer look, you can find marine animals everywhere.

Geographic sea hare (Syphonota geographica)

Biscuit sea star (Goniodiscaster scaber)

Painted sand star (Astropecten sp.)

Flowery sea pen

Oh.... Whose siphon does this belongs to?

Who am I?

It is a noble volute (Cymbiola nobilis)! This is my first time seeing a buried noble volute, with only its siphon visible.

Noble volute

This ornamented snapping shrimp (Alpheus sp.) looked rather lost on the seagrass patch. Snapping shrimps poor vision and they require the help of a goby "partner" to help find its way back to its burrow by keeping one of its antennas in contact with the fish.

Ornamented snapping shrimp

And with the latest hype about large emergence number of tropical swallowtail moths (Lyssa zampa), I found the sea version. Presenting the "sea zampa":

It is just part of the wings of Lyssa zampa.

Now for the interesting finds of this trip.
Chay Hoon found a cute juvenile knobbly sea star (Protoreaster nodosus), or so we think it should be the juvenile. It is greenish.

Overview

Underside

Tube feet on one of its arms.

Moving on the silty bed of seagrass was a cerberilla nudibranch (Cerberilla sp.), spotted by Chay Hoon. I found another one later in the trip.

Cerberilla sp.

There was also the tiny black gymnodoris nudibranch (Gymnodoris sp.).

Overview

Side view, with a glimpse of underside

The mini carpet anemone (Stichodactyla tapetum) were scattered everywhere on the seagrass meadow. I noticed that they have a stalk body column, which made them look like sprouting tiny sea mushrooms.

Mini carpet anemone

Side view, with the body column visible.

The most interesting find for this trip has to be this swimming acorn worm. We usually see the buried form of the worm with evidence of it through its strings of "poop" coming out of the ground. However, the one we saw was swimming in the sheen deep water and we gently scooped it up. The acorn worm was moving so fast that I could not get a proper full shot of the worm. I only managed to capture a half length shot of the worm.

Acorn worm

Despite the unhappy end to the trip, it was a great morning to spend at Changi beach and seeing so many interesting animals.

Best of all, I made it to school on time for morning assembly.

Posts by others:
Chay Hoon on her Facebook
James Chua on his Facebook
Kwan Siong on his Facebook
Ria Tan - Changi with colourful slugs