Mantle robust, slightly flattened dorsoventrally. It can be broad or slender; oval, oblong or nearly circular in outline. The anterior of dorsal mantle margin projected forward, not fused with head. Fins narrow which located dorsolaterally on mantle, approximately equal to mantle length; posterior fin lobes free, not connected to each other. Head is robust and slightly narrower than mantle. Eyes are prominent, which covered by a transparent membrane and a conspicuous secondary fold on the eyelid. Mouth surrounded by 10 appendages (8 arms and 2 tentacles). The cuttlefish arms consist of 2 to 4 suckers in transverse rows. Tentacular clubs consists of four or more suckers in transverse rows and tentacles retractile into pockets on the ventrolateral sides of the head between arms III and IV. Internal calcareous cuttlebone was located dorsally in the mantle which underneath the skin and cuttlebone length usually equal to the mantle length. The cuttlebone shape are ranges from lanceolate to oval or diamond-shaped whereas dorsal side is calcareous plate and ventral side finely laminate. Buccal membrane present, with or without suckers; each radula tooth unicuspid (with a single projection).
Genus: Sepia Linnaeus, 1758
Species: Sepia brevimana Steenstrup, 1875
Mantle blunt-pointed posteriorly. Tentacular club is small with 5 to 8 suckers in transverse rows and swimming keel extending well beyond the sucker-bearing. Dorsal and ventral protective membranes not fused at base of club and dorsal membrane much wider than ventral membrane. Cuttlebone very angular with V-shaped anteriorly and narrow sulcus extending along striated zone, flanked by rounded ribs. The dorsal surface flat and the texture uniformly pustulose. Spine is long and present with keels dorsally and ventrally, also with nose-like protuberance in the anterior part of spine. Inner cone limbs broaden posteriorly, thickened, rose-coloured or yellowish orange, outer margin of inner cone forming a raised, flattened ledge posteriorly; outer cone narrow anteriorly, broadens posteriorly.
Sepia rostrata (in part) Férussac and d Orbigny, 1848.
Sepia brevimana Steenstrup, 1875- [Carpenter and Niem (1998): 740; Jereb and Roper (2005): 77-78]
Indo-Pacific: northern Indian Ocean, Andaman Sea, Andaman and Maldive Islands, Singapore to the Gulf of Tonkin, South China Sea, Hong Kong, Java, Sulu and Celebes Seas.
Sepia brevimana has been assessed as Data Deficient in the IUCN Red List. It is caught as by-catch off eastern India and there are fisheries off Thailand and in the South China Seas, but few landing data are available and population trends are not known.