The black stink sponge (Ircinia arbuscula), is a species of sea sponge in the family Irciniidae.

[1] This sponge is known around the Australian coast and around South Africa from the Cape Peninsula to Cape Agulhas.

It is a black encrusting sponge which forms a mat on rocks.

Its surface is textured, and the sponge is firm and slippery to touch.

[2][3] This sponge lives on rocky reefs subtidally down to 180m.