The path to success in fish sperm

In many animals, males pursue alternative tactics when competing for the fertilization of eggs. Some cichlid fishes from Lake Tanganyika breed in empty snail shells, which may select for extremely divergent mating tactics. A recent study at the Institute of Ecology and Evolution of the University of Bern shows that different male types within a species produce divergent sperm, specializing either in speed or longevity. In the context of reproductive competition, males find different ways to enhance their odds. This may include flamboyant colours, gorgeous feathers, impressive antlers or conspicuous courtship displays. Now a team lead by Michael Taborsky at the Behavioural Ecology Division of the University of Bern found that the harsh competition for fertilizations can result in the production of specialized sperm in dependence of the particular mating tactic pursued by a male. Dwarf males versus bourgeois territory holders .