The larger males, some with bodies measuring more than 60 centimetres (total length up to a metre), sparkle, pulsate and flash with iridescent colours in their attempts to attract a female.

Males outnumber females by 11 to one and fiercely guard those in their territories.

Competition to breed is fierce, and while one minute these relatives of the octopus are swimming through the water with consummate grace, the next they shoot water through their siphon and take off at speed to engage in a life or death battle with another male.

However, it’s not unusual for smaller males, who have previously changed colour, to mimic a female to take advantage of the combat and sneak in and mate.

All this takes place in relatively shallow water – about four metres – which is ideal for snorkellers. Some areas, such as Stony Point, are even suitable for younger (capable) swimmers; but there are many great spots including sheltered coves where this epic display can be viewed.

Although cuttlefish breeding begins in May, the best time to see them is June and July when the season is in full swing.

Whyalla Diving Centre has maps, directions and information.

You can also swim with the cuttlefish with Experiencing Marine Sanctuaries guided tours from July 7-9. Book your spot before June 7 to receive 33 per cent off (early-bird special) or 66 per cent off for Eyre Peninsula locals.

0466-278-187, www.emsau.org

This story originally appeared on The Senior.