Violet Sea Apple

Overview

The Violet Sea Apple (Pseudocolochirus violaceus) is a vibrant, rotund sea cucumber known for its striking coloration and unique defensive behaviors. Native to the Indo-Pacific and the east coast of Africa, this echinoderm is frequently observed attached to hard substrates like coral reefs and rocky rubble where water currents are present.

Appearance

This species typically reaches lengths of 10 to 20 cm. Its body is often ovate or sausage-shaped, featuring five rows of bright yellow tube feet used for movement and attachment. The coloration is highly variable, often displaying shades of red, lilac, and white, with a mouth ringed in blue. When fully extended, the animal displays a crown of feathery, branched tentacles that are often tinged with purple, yellow, and white.

Biology & behavior

Sea apples are known for their ability to inflate their bodies with seawater, allowing them to swell significantly and drift with currents to new locations. If threatened, they possess several defense mechanisms, including the ability to expel their internal organs or release a toxic substance called holothurin into the water. They are often found partially hidden or fully exposed, keeping their tentacles expanded to feed even during daylight hours.

Feeding

As suspension feeders, they rely on water currents to deliver food. They use their mucus-coated, branching tentacles to capture plankton and organic particles from the water column. Once a tentacle is coated with food, the animal curls it into its mouth to scrape off the nutrients before resetting the tentacle to continue feeding.