Scientists have discovered that semen from sea lampreys contains a chemical that attracts ready-to-mate females with its smell. Researchers from Michigan State University and Shanghai Ocean University discovered the aphrodisiac pheromone spermine, originally found in humans, in fish semen. In order to mate, male members of the jawless species defend individual nests, while females move between them depositing large numbers of eggs. Scientists found that the odorous compound spermine alerts females to the presence of spawning males - but does not attract those who are not producing eggs. Michigan State University's Anne Scott said: 'We found the semen of sea lamprey contains spermine, a highly specific and potent pheromone, which attracts only ready-to-mate female sea lampreys.
How are the little swimmers doing? Low sperm counts or poor sperm quality are to blame in around a third of cases of couples who can't conceive. A visit to a clinic for a test can be awkward, but a new smartphone-based system lets men determine whether that's necessary by checking their fertility in the comfort of their own home. Men often find it embarrassing to provide a semen sample at a clinic, says Yoshitomo Kobori of the Dokkyo Medical University Koshigaya Hospital in Japan. So Kobori devised an alternative.