Australian Giant Cuttlefish

Stony Point, near Whyalla in northern Spencer Gulf, provides shore access to the annual breeding aggregation of Australian giant cuttlefish (Sepia apama). Each winter, usually from May through August, tens of thousands gather over shallow rocky reef and macroalgae habitat to mate and deposit eggs beneath stones. Divers and snorkelers can observe males rapidly changing color, pattern, and skin texture while competing for females; smaller males may conceal typical male markings to approach females unnoticed. The aggregation is internationally significant because it is the only known spawning gathering of cuttlefish occurring at such density and predictability. Part of the breeding habitat is protected within the Upper Spencer Gulf Marine Park.

Fun Fact: Smaller male Australian giant cuttlefish can disguise themselves as females to pass larger guarding males and gain access to a mate—one of the most remarkable documented examples of tactical sexual mimicry in the marine world.