Sepia cottoni is a species of cuttlefish

Cuttlefish

Cuttlefish are marine animals of the order Sepiida. They belong to the class Cephalopoda . Despite their name, cuttlefish are not fish but molluscs....

 native to the southeastern Indian Ocean

Indian Ocean

The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...

, specifically from northwest of Broome

Broome, Western Australia

Broome is a pearling and tourist town in the Kimberley region of Western Australia, north of Perth. The year round population is approximately 14,436, growing to more than 45,000 per month during the tourist season...

 (17°31' S) to Armstrong Point, Rottnest Island

Rottnest Island

Rottnest Island is located off the coast of Western Australia, near Fremantle. It is called Wadjemup by the Noongar people, meaning "place across the water". The island is long, and at its widest point with a total land area of . It is classified as an A Class Reserve and is managed by the...

 (32°0' S). It lives at a depth of between 83 and 183 m.

S. cottoni grows to a mantle

Mantle (mollusc)

The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...

 length of 55 mm.

The type specimen was collected west of Lancelin, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 (31°54′S 114°55′E). It is deposited at the Western Australian Museum

Western Australian Museum

The Western Australian Museum is the state museum for Western Australia.The Western Australian Museum has seven main sites: two in Perth within the Perth Cultural Centre, two in Fremantle , and one each in Albany, Geraldton, and Kalgoorlie-Boulder...

 in Perth

Perth, Western Australia

Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....

.