The body and tentacles of the Sea Apple, or Philippine Sea Apple, can be a vareity of colors, but it always has yellow feet. The oral region is usually blue to violet, hence the common name Violet Sea Apple or Violet Sea Urchin.
It prefers an established reef aquarium with room to move about, and large amounts of live rock from which it receives a majority of its food. Once it finds a favorable location, usually in a high current area, the Sea Apple will generally stay there.
Protect all intakes on pumps and power heads, to eliminate any possibility of being sucked in. It is very sensitive to high levels of copper-based medications. Sudden changes in pH or salinity can cause it to shed its oral tentacles.
Do not house these cucumbers in an aquarium that contains any fish that may pick on its tentacles. Generally, any fish that is prone to pick on feather dusters, will pick on the tentacles of the Indonesian Sea Apple. These fish include; Butterflyfish, Large Angels, and any species that is listed not safe with invertebrates.
When feeding, it will extend its oral tentacles into the current to filter out food. As the food is trapped, it will then draw its entire tentacle into its mouth. In the aquarium, it will need to be fed a diet of phytoplankton - frozen, liquid, or dried - on a daily basis.