Marine life  /  Sea cucumbers  /  Synaptid sea cucumber
Reviewed 2026-09-05
Species entry

Synaptid sea cucumber

Synapta maculata

Up to three metres of soft body draped over rubble, and it sticks to a wetsuit.

Size
To 300 cm
Depth
0–20 m
Habitat
Rubble, seagrass and silt
Active
Night
Range
Indo-Pacific
Rarity
Lembeh Strait
1 star of 5, found on most dives
SP-01
synaptid sea cucumber · full body · habitat
4:3 · min 2400px

The longest sea cucumber, reaching three metres and occasionally more, but only a few centimetres thick — a soft, extensible tube patterned in brown and cream longitudinal stripes, draped and looped over rubble and weed. The front end carries fifteen feather-shaped tentacles which are swept over the substrate and wiped into the mouth one at a time. It has no tube feet and no respiratory tree, which is why the body is so thin and so flexible.

The skin is embedded with microscopic anchor-shaped ossicles that catch on anything fibrous, so the animal adheres firmly to a wetsuit or a glove and tears rather than letting go — a good reason not to pick one up, quite apart from the damage. Under stress it can rupture and shed a section of body. Grazes detritus, mainly at night. Recorded from the intertidal to about 20 m. Emperor shrimps and small crabs are sometimes found riding along the body.

Where to find:

LocationRarity Best monthsDepthHabitat
Lembeh Strait Indonesia editorial estimate
1 star of 5, found on most dives
Year-round
0–20 m
Rubble, seagrass and silt

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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