Needle cuttlefish are recognized by three circular markings on their body - the rear one consists of a ring of white spots. The mantle can change its shape to resemble spines.

This species is common on coral reefs and areas of sand in shallow water. It walks along the bottom, using its third pair of arms and back mantle flaps. It is active at night when it hunts small fish and crustaceans. It is often found close to echinoderms where it finds prey easily.

This is a solitary species but they can occasionally be found in pairs. They are found mostly during the day, walking on their lower arms and with their back mantle flapping along the sandy bottoms of the Strait. They hunt for small fish and crustaceans. Their flamboyant colours are displayed when alerted to warn potential predators of their toxicity. The toxins contained in their muscles have the same lethality as those possessed by their cousin, the blue ring octopus. They can be observed laying eggs under empty coconut shells from January to July.

Broadclub cuttlefish are usually found free swimming in reef areas. They are active during the day and can often be seen hunting for fish and crustaceans. They are the most common species of cuttlefish on coral reefs. They are capable of rapid color change, usually into a spotted white and brown pattern, and their large eyes have a bright yellow rim. Their common name is derived from the broad club-like feeding arms. Can grow up to 10kg in weight. Second largest Sepia cuttlefish species.