This species grows to 25 cm in diameter, with articulated plates making the test quite flexible and accounting for its binomen.

It subsists on a great variety of food including algae, coral polyps and bottom detritus.

It is most active at night and is named for the extreme pain inflicted by its spines and its occurrence in the Red Sea.

It is well distinguished from the oceanic A. varium by its spine and test morphology: The IA spines regularly cover the entire aboral side in A. marisrubri, but grouped in rectangular patches, separated by naked areas, in A. varium.

- Diversity and Recent Changes in the Echinoderm Fauna of the Gulf of Aqaba with Emphasis on the Regular Echinoids, Dafni, J., Ben-Gurion University, Eilat Campus[2] It often affords shelter to the commensal shrimps Allopontonia iaini, Periclimenes colemani, and the parasitic gastropod Leutzenia asthenosomae.