The world's abalone are threatened, endangered or otherwise vulnerable in nearly every corner of the planet. If only we could wave a magic wand to know when abalone are ready to reproduce, without even touching them. Scientists have now found that wand -- although it isn't magic, and it only looks like a wand. It's an ultrasound transducer, and it can be used to quickly and noninvasively detect when abalone are ready to spawn, they report in a study this week.