Deck MusselSeptifer bilocularis

  • Rocky Shores
  • Mollusc
  • Bivalve
  • Mussel


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.

Habitat and ecology

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].


Conservation and management

The conservation status of this species has not been evaluated yet.


[1] ‘Septifer Bilocularis, Box Mussel’.

Did you know?

This species can reach a maximum length of 5cm.