Sepia plana

Sepia plana is a species of cuttlefish native to the coast of Australia, specifically the North West Shelf (-12.06667°N, 122.98333°W to -17.925°N, 118.26667°W). However, cuttlebones of this species have also been found off eastern Australia, suggesting that it may have a wider distribution. S. plana lives at depths of between 396 and 505 m.

S. plana exhibits sexual dimorphism, as females grow considerably larger than males. They reach a mantle length of 151 mm and 99 mm, respectively.

The type specimen was collected in the North West Shelf, western Australia (-14.25°N, 121.98333°W). It is deposited at the Museum of Victoria in Melbourne.