The sponge is massive, rounded and often grossly bulbous. It grows up to 30 cm in greatest dimension. The surface is smooth. There are 3 intergrading kinds of oscules (A. nsp-close-up): 1) slit-like often meandering and branching invaginations, 1-3 mm wide, up to 5 cm long; 2) more or less circular oscules, occasionally coalescent, 2-7 mm in diameter, irregularly scattered and rather widely spaced, usually with sharp, flush rims; and 3) smaller, more regularly scattered and numerous oscules, circular to elongate, 1-2 mm wide, often clustering, sharp-rimmed, flush. The consistency is firmly spongy, somewhat resilient.
The color is reddish brown to walnut-brown.
The species seems to prefer the reef community. From the drop-off to 50 meters depth. Sponge brittle stars (Ophiothrix suensonii ) often live inside the sponge.
The distribution is uncertain caused by taxonomic problems.