Monday, May 12, 2008

Moon Snail Feeding

Watch carefully, the Moon snail release a bivalves after consumed and go burrowing! Moon snail have a very beautiful appearance, smooth and gloosy shell actually a fierce predator.




Sunday, May 11, 2008

Helmet Shell at Changi?

I was back at Changi again to catch the low tide before it ended. It was as crowded although it was raining heavily earlier this morning. The shore are packed with swimming, fishing and pick & choose activities.
Due to the rain earlier on, most of the animals had burrowed to stay away from the fresh water. Animals that do not burrow such as fan shells just like sitting duck - have to endure the fresh water and just waiting to be picked by predators (to me, human is their biggest predators).
This sea cucumber was half burrowed when I spotted it.
So as this Moon snail.This lump of seaweed looks like a sea cucumber when I found it near the sea grass bed.After a few wash... yes is a sea cucumber!and another Ball Sea CucumberThe little pink sea cucumbers are the only animals that can be found easily. They just attached to sea grass or anything that is not moving. This sea cucumber extending the tenticles to feed.I have no idea what shell is this but it do looks like a helmet shell.This is the only Striped hermit crab that I saw this morning.Saw this tiny Moons crab swimming from one place to another so I pick it up to take his photo. It dissapear immediately the minute I put it back to water. Moons crab with all leg flattened can swim faster than swimming crabs and burrow in lightning speed!This flower crab almost invisible when it stay motionless on the seagrass bed. There are a few anemones here and there but the colour show that they are not very healthy. Too much fresh water again?

Hundreds of Geographic sea hares that we saw on Friday are no way to be found. I wonder are all of them burrowed into the sands or they prefer to stay at the deeper water?

Saturday, May 10, 2008

Changi Tidal Walk

I was one of the guide for students from MGS sharing with them on plants & animals living in the beach and marine habitat.
There are lots of small sand balls on the beach creation of Sand bubbler crabs. Sand Bubbler crabs eat thin coating of detritus from sands and processed sands are discarded in small balls.

We saw quite a few number and spicies of sea cucumbers.The Ball Sea Cucumber that we saw are usually about the size of tennis ball. This is the first time seeing a Ball Sea Cucumber with the size of a coconut!

There are lots of white sea urchins on the sea grass bed. The pure white sea urchin,

red banded white sea urchin andsome in purple!A beautiful Striped hermit crab. Unlike other true crabs, Hermit crabs have a long & soft abdomen and need a shell for protection. They are vulnerable to predators and drying out without a shell.The hermit crab on the left is too big to stay in his existing shell. Hermit crabs has to move out of its shell into a larger one when they grow bigger. The two hermit crabs above are in the process of what I call a 'agreesive negotiation'. Looks like the smaller hermit crab on the right refuse to exchange its shell.

This is the reason why we should not remove any shells (even is empty) from the shore. Doing so will have a impact on the hermit crabs. They will have one house less to stay in!The Moon crab ( Ashtoret lunaris) with all their legs flattened to help them swim faster and burrow faster into sands in lighting-speed!Elbow crab (Parthenope longimanus) has two super long pincers but are slow moving by nature. They usually hide in mud or sand among the seaweeds and are very difficult to spot them.Unlike other anemones, this Swimming Anemones do not live in tubes and usually found in seagrass bedsA Noble volute (Cymbiola nobilis) can grow up to about 15cm and prey on bivalves.We saw 3 baby Knobbly Sea Stars (Protoreaster nodosus) today. The one on top similar to Knobbly that was found at Semakau and other part of Singapore and 2 more with slightly different colour and the 'knob' arrangement. Check it out on my previous posting on 12 April 08 and 9 May 08. Related to sea stars, Sand Dollar (Arachnoides placenta) usually burried in sand.This fish with a very beautiful and striking dots suddently emerge from the sand. I have no idea of the id.The Geographica Sea Hares (Syphonota geographica) really in the seasons. Every few steps you'll sure to find one. They feed on algae on the intertidal area and like other sea hares, they will release purple ink to shocks and confuse their predator.Only the eyes and mouth partly exposed waiting for small animal that crosses its path.
The eerie face slowly appear after a few rinse by incoming sea waters.The Stargazer suddently open his big mouth and 'spit' out water and sands that was washed in by the tide. This suprise move really send the students start screaming! OMG... the head is as big as a bowl!

Before we knew it, is time to return to shore as the tide is coming in. It was a very enjoyable walk.Capturing that happy moment before leaving this wonderful shore with such a lovely biodiversity.