Septifer bilocularis is a bivalve from the Mytilidae family, also known as the Box Mussel. It has a thick, elongate shell that varies in shape, of a deep green colour that gradually becomes brownish and paler towards the umbones, (the highest point of each articulating part of the shell). The interior is a bluish grey to purplish brown.
This species is present across the Indo-Pacific region, from East and South Africa to Japan, Australia, New Caledonia and Eastern Polynesia. Recorded depth range is between 0 to 15m. It is found on exposed areas such as rocky shores, coral reefs that experience strong currents. It can be found living with algal species, Corallina officinalis, in rock pools between tide marks[1].
The conservation status of this species has not been evaluated yet.
This species can reach a maximum length of 5cm.