Cross-dressing cuttlefish

How do you woo a member of the opposite sex whilst simultaneously confusing potential rivals? Male cuttlefish have come up with an interesting solution: cross-dress on one side of your body. For the first time, these creatures have been spotted using their male skin pattern to court females, whilst on their other side displaying a female pattern in order to avoid competition from other males.

The cuttlefish – actually a mollusc rather than a fish – is sometimes called the ‘chameleon of the sea’ because of its ability to change skin patterns. Members of the mourning cuttlefish (Sepia plangon) species, for example, sport vivid, dynamic skin motifs – mottled patterns for the females and tiger-like stripes for the males.

While studying wild cuttlefish in Sydney Harbour, biologists at Macquarie University observed strange behaviour. When a male was in a group with a female and another male, he’d often keep his true male colours facing the female, but transform his opposite side to mimic the female patterns, preventing the rival male from challenging him.

As well as showcasing the mollusc's impressive social intelligence, the researchers claim that this behavior can help to ease the romantic strife of a male cuttlefish.

“It can take a while to win the female’s heart,” says Martin Garwood, a co-author of the study. “By deceiving the rival male, the deceptive male can get the job done without being interrupted or challenged.”