Dried seahorses

The aphrodisiac counter is always the most arresting section in the menageries that are Chinese medicine shops. Among the eyes of newts and toes of frogs are mounds of dried seahorses. In traditional Chinese medicine, consuming seahorses is thought to be beneficial for human kidneys, improving memory, reducing swelling, helping women give birth, treating arthritis and even curing breast cancer. But the most important function of the humble hippocampus is the treatment of impotence. Maybe it has something to do with the fact that seahorses are the only known vertebrate species for which males rather than females give birth. Or maybe it's just because they are so exotic.

For most of the past 1,000 years, only the richest Chinese patients could afford to include seahorses in their love potions. But with industrialisation, rapacious modern fishing techniques and China's economic renaissance, dried seahorses have become widely available and are even sold pre-packaged by the dozen in supermarkets across the country.