In its native Pacific waters, the sea slug Siphopteron makisig looks tiny and delicate, like a bud of colored glass. But in reality this slug is a mirror-image mating machine, as modeled by the pair ...

Courting is as unique to a species as dietary habits or dwelling. Some mating rituals seem almost aggressive, while others are dance-like and graceful. They can even be beautifully intimate, mimicking ...