Bohadschia marmorata

Lore & Background

Bohadschia marmorata is cylindrical in shape and grows to about 35 centimetres long. Its body wall is tough and leathery with a rough texture due to calcareous spicules. It is covered in translucent papillae up to 1 centimetre across and a few short spines. The anterior end is somewhat narrowed with a mouth surrounded by retractile tentacles; the posterior end is rounded with an anal opening. Adjoining the anus is the cloaca, through which defensive white sticky threads (cuvierian tubules) may be ejected when the animal is stressed. The cloaca also connects to the respiratory tree, into and out of which water is pumped for gas exchange. Body colour is cream or orange partially obscured by variable numbers of dark brown speckles and blotches, with a wide pale longitudinal stripe on the underside and many short, slender tube feet with knobbly tips.

It is found in the Indo-Pacific Ocean, from the Red Sea and east coast of Africa to Japan, the Philippines and Australia. It lives on sandy or gravelly bottoms of shallow water areas and seagrass meadows at depths down to about 36 metres, often semi-submerged in the sand.

As a detritivore, it uses its tube feet to move around and scoops sand, mud and debris into its mouth with its oral tentacles. After processing this material in its gut, it voids the remains, leaving a characteristic trail of sand on the seabed.

Reader's Guide

Bohadschia marmorata is significant as a detritivorous sea cucumber that plays a role in processing sand and organic debris on the seabed, leaving characteristic trails. Its defensive mechanism—ejecting sticky white cuvierian tubules from the cloaca—is a notable adaptation against predators. The species is also distinguished by its tough, leathery body wall containing calcareous spicules, and its variable coloration of cream or orange with dark brown speckles and blotches. Its range across the Indo-Pacific, from the Red Sea and east Africa to Japan, the Philippines and Australia, and its habitat in shallow sandy or gravelly bottoms and seagrass meadows down to 36 metres, underscore its ecological role in these environments. The species is often semi-submerged in sand, and its tube feet and oral tentacles are used for locomotion and feeding. The respiratory tree connected to the cloaca facilitates gas exchange. These features collectively highlight its adaptation to a benthic, detritus-based lifestyle.

Did You Know?

• Bohadschia marmorata can eject defensive white sticky threads (cuvierian tubules) from its cloaca when stressed.
• It grows to about 35 centimetres (14 in) in length.