It is among the sea cucumbers harvested for food in Madagascar.
Here's a closer look at it.
It had a distinct underside; flatter and more plain.
This sea cucumber was also seen on Cyrene Reefs in July.
Both the Changi and Cyrene sea cucumbers were found buried in sand at the mid-water mark near seagrasses, with only a little bit of their body sticking out.
It was also seen at Chek Jawa as shared by Kok Sheng on his wonderful creations blog.
According to the UNEP-WCMC website (United Nations Environment Programme and World Conservation Monitoring Centre), the distribution of this sea cucumber is Australia, Indonesia and the Philippines.
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And we'll keep looking carefully to find more of Singapore's little known marine life.