Robust sea cucumber

Appearance

''Colochirus robustus'' is roughly cylindrical with 5 shallow longitudinal ribs and grows to about 7 centimetres in length. It has an angular appearance and finger-like or thorn-like protuberances on the ribs. At the anterior end is a ring of about eight large, feathery feeding tentacles. There is a slight transverse indentation near the rounded posterior end. There are three rows of tube feet on the underside. The colour is a vivid yellow, sometimes with grey between the ridges.

Distribution

''Colochirus robustus'' is found in the tropical waters of the central Indo-Pacific region at depths down to about 25 metres . Its range includes the Philippines and Indonesia.

Behavior

''Colochirus robustus'' is usually found on rocks and reefs in places with moderate to rapid water flow. It clings to the substrate with its tube feet, spreading its feathery tentacles to catch zooplankton and other organic particles as they float past. The tentacles are then retracted to the mouth where the food particles are scraped off.

''Colochirus robustus'' can reproduce both sexually and asexually. In the latter case, fission can take place with a transverse crack developing halfway along the body and gradually widening until the two halves split apart. The posterior end then grows a new anus while the anterior end develops a mouth and new tentacles.

Uses

''Colochirus robustus'' is sometimes kept in reef aquaria because of its distinctive appearance. It is only recommended for experts however as it may release toxins into the water if stressed and has specialised feeding requirements.