Marine life  /  Sea cucumbers  /  Yellow sea cucumber
Reviewed 2026-09-06
Species entry

Yellow sea cucumber

Colochirus robustus

A small bright yellow cucumber that feeds with branched tentacles, usually in a group.

Size
To about 7 cm
Depth
5–30 m
Habitat
Sponge, rubble and structure
Active
Day and night
Range
Indo-Pacific
Rarity
Lembeh Strait
2 stars of 5, usually seen in a week
SP-01
yellow sea cucumber · full body · habitat
4:3 · min 2400px

A small dendrochirotid holothurian to about 7 cm, bright to deep yellow, the body a stiff tapering cylinder with five rows of pointed papillae running its length and a ring of ten branched tentacles at the front end. It sits upright or leans out from the substrate with the front end raised, which is not how the large sand-dwelling cucumbers behave, and the combination of the colour, the small size and the raised posture is the identification.

The tentacles are the feeding apparatus. They are held out into the current in a bowl, and one at a time each is folded into the mouth and stripped of the particles caught on it, so the animal works through the ring in a rotation. Feeding is more or less continuous where there is water movement and stops when there is none.

They occur in aggregations, on sponges, rubble, dead coral and man-made structure, and a single square metre may carry twenty. Colour is consistent enough that they are conspicuous from a distance despite the size, and they are among the easier subjects on a muck site because they neither move nor retract quickly. Recorded from about 5 to 30 m.

Where to find:

LocationRarity Best monthsDepthHabitat
Lembeh Strait Indonesia editorial estimate
2 stars of 5, usually seen in a week
Year-round
5–30 m
Sponge, rubble and structure
Ambon Indonesia editorial estimate
2 stars of 5, usually seen in a week
Year-round
5–30 m
Silty rubble and structure
Anilao Philippines editorial estimate
3 stars of 5, a good week should turn one up
Year-round
5–30 m
Sponge and rubble
Bali Indonesia editorial estimate
3 stars of 5, a good week should turn one up
Year-round
5–30 m
Rubble and rock
Dauin & Dumaguete Philippines editorial estimate
3 stars of 5, a good week should turn one up
Year-round
5–30 m
Rubble and sponge

Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.

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