There are about 1400 known species worldwide. They are classified into six orders and in total 25 families. I’ve so far seen representatives from five families on our intertidal shores. The latest is this one representing the synaptids.
A typical synaptid from the Order Apodida has no tube feet, has a very thin and sticky body wall and has no respiratory trees. Apodids’ oral tentacles can be simple or digitate or, like this individual has so beautifully demonstrated, feather-like.
This species is most probably a Polyplectana kefersteinii. But of course we would have to examine its microscopic ossicles to be 100% certain of the identification.
Picture and video taken at: A southern offshore island, March 2007 and Pulau Semakau, May 2007.
Kerr, A. M., Holothuroidea. Sea cucumbers.
Lane, D. J. W. & D. Vandenspiegel, 2003. A Guide to Sea Stars and other Echinoderms of Singapore, Singapore Science Centre, Singapore.