Sea Apple - Pseudocolochirus violaceus
It may not seem much an apple, nor a cucumber, but these are colorful sea cucumbers commonly known as Sea Apples belonging to the species Pseudocolochirus violaceus (Holothuroidea - Dendrochirotida - Cucumariidae), which occurs in the Indian Ocean and the western part of the Pacific Ocean.
Sea apples are about 18 cm long. They usually are purple, but also can be blue, red, white, and yellow. Three rows of tube feet run along the bottom side of the animal. The top side has two rows of tube feet as well as small scattered tube feet. The body is curved so that the mouth and anus point upward. They have ten tentacles which are bushy purple to red and have white tips. The pieces of the body wall skeleton are rounded, smooth plates with a few holes.
When relaxed, the normal shape is short and sausage-like as with most other sea cucumbers. When stressed, however, it may inflate itself into a large round ball.
Sea apples live partly hidden to fully exposed with tentacles expanded, even during the day. They feed continuously, capturing large food particles with outstretched branching tentacles that are lightly coated in mucus.
These beautiful sea cucumbers unfortunately are harvested for the aquarium trade. Ironically, they do not make good aquarium specimens as they are often toxic to their tank mates.
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Photo credit: [Top: ©René Cazalens | Locality: Komodo, Indonesia, 2010] - [Bottom: ©Chuck and Jean | Locality: Manila Ocean Park, Philippines, 2008]