We're often told that males are eager and females coy. But the story is not quite so simple if you are a two-spotted goby, researchers from the Norwegian University of Science and Technology's (NTNU) Department of Biology have found.

Two-spotted gobies are tiny fishes with a remarkable sex life amongst the seaweeds. Snorkeling in chilly Nordic waters, PhD candidate Lise Cats Myhre and her colleagues at NTNU followed several hundred female gobies as they played the fish version of the mating game. The team saw a complete change in sexual eagerness in the two sexes as the season progressed, which they report in the June issue of American Naturalist.

Whilst spring shyness was the rule amongst the fish ladies, mid-summer females were anything but coy: they almost always took the initiative in love affairs, and very rarely rejected a male mating offer. For goby boys it was it was exactly the opposite: they were eager to mate in the cold spring waters, but seemingly had no interest in ladies and sex in high summer.