Eye-spotted sea cucumber that fires sticky white tubules and houses a pearlfish.
A large, thick-bodied sea cucumber, commonly 30 to 50 cm and reaching about 60, cream to fawn, grey or pale brown, and covered over the upper surface in dark eye spots — a brown or black ring around a paler centre — which is what the species name refers to. The mouth is ringed by short shield-shaped feeding tentacles. Bohadschia vitiensis and B. marmorata are the same shape and general colour but blotched rather than marked with ringed ocelli; Pearsonothuria graeffei, which has its own entry and was once placed in this genus, is slimmer and has heavily branched black-and-white tentacles.
It is a deposit feeder. Sand is taken in at the mouth, organic film and small organisms are stripped out in the gut, and clean sand is left behind in casts. Its defence is the Cuvierian organ: a mass of fine white threads discharged from the anus when the animal is handled, which lengthen and become extremely sticky in water, entangle a crab or a small fish, detach from the cucumber and are regenerated over the following weeks. The body wall also carries holothurin, a saponin, which is the reason the animal is left alone by most things that could otherwise eat it.
This is one of the productive sea cucumbers to check for passengers, and there are three worth knowing. The sea cucumber crab Lissocarcinus orbicularis, white with dark rounded blotches, rides the body wall and is often near one end. The emperor shrimp Zenopontonia rex occurs on it, pink and white against the spotted skin. And a pearlfish — Encheliophis or Carapus — commonly lives inside the respiratory tree, entering the cloaca tail first and leaving at night to feed; on an occupied animal the fish’s head is sometimes visible at the anus, and that is as much of it as most divers ever see.
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.