Sepiella mangkangunga 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 Indo-Pacific

Indo-Pacific

The Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia...

, specifically off the Northern Territory

Northern Territory

The Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...

 in 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...

 (12°48′S 130°21′E to 13°14′S 130°57′E). It lives at depths from 1.1 to 3.3 m.

Females are on average slightly larger than males. They grow to 59 and 58 mm in 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, respectively.

The type specimen was collected off Stingray Head in the Northern Territory

Northern Territory

The Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...

 (12°48′S 130°21′E). It is deposited at the Museum and Art Gallery in Darwin

Darwin, Northern Territory

Darwin is the capital city of the Northern Territory, Australia. Situated on the Timor Sea, Darwin has a population of 127,500, making it by far the largest and most populated city in the sparsely populated Northern Territory, but the least populous of all Australia's capital cities...

.