Sea apple at Changi

On a predawn morning, we were out at Changi and for me, I was checking out my sand stars.


Among the seagrasses, I stumbled upon something that has stunning red colour. Upon a closer look, it is a Sea apple (Pseudocolochirus violaceaus) which is a sea cucumber. It's my first time seeing this rare animal, which is listed among the threatened animals of Singapore due to habitat loss and overcollection according to the online Chek Jawa guide by Ria Tan.


Ironically, they do not make good aquarium specimens as they are highly toxic to their tank mates. They are sometimes coined as "tank bombs" for their toxicity.


According to the online Chek Jawa guide, colourful sea apples are sometimes seen on the coral rubble area, clinging to the rubble with their yellow tube feet that emerge in three rows on the underside. During low tide, they retract their colourful feeding tentacles. When relaxed, their normal shape is sausage-like as most other sea cucumbers. When stressed, however, they often inflate themselves into a large round shape.

The Sea apple gathers plankton and edible bits from the water with its branched feeding tentacles. The feeding tentacle is inserted one by one into the central mouth and 'wiped clean' of any edible bits.


The shape of this tunicate looks like the sea apple but it is an ascidian.


There are also many stars like this juvenile biscuit sea star.


And yes, another one of the many biscuit stars.


This juvenile star is highly possible to be a cake sea star.


And I'm so glad that my Astropecten sand stars are doing very well. This photograph was taken in situ in their natural state.


The shore is alive with peacock anemone, phoronid worms and even a seahorse!


Here a close up on the phoronid worms. Ria posted more information about phoronid worms that were seen at Pasir Ris.


These phoronid worms usually can be found beside peacock anemones.


And this is a juvenile peacock anemone which I thought is much cuter. :-)


There were also a number of carpet anemones on Changi.


And it is nice to see the peacock anemone and the carpet anemone side by side, though the former is not a true anemone.

Changi is always full of surprises, the last time the bailer snail, now the sea apple cucumber!