ROLE REVERSAL
Seahorses, pipefish and seadragons – otherwise known as syngnathid fish – are famous for their sex-role reversal, in which females court males and males gestate the young. And now female pipefish have been shown to perform another traditionally masculine role.
Like black grouse and kob antelope, worm pipefish, a UK species that breeds in the intertidal zone, form leks in which one sex gathers en masse to display to the other.
Unlike almost all lekking species, though, it’s the colourful females that display to the males. The most flamboyant females are found in the centre of the lek and are actively sought out by males because they lay larger clutches.
“Females consume all their body fat during egg production and maturation,” says Nuno Monteiro of the University of Porto, Portugal. “It is natural that only high quality females have the potential to mature several egg batches that can be passed to many males.”
This behaviour is highly unusual: female leks are otherwise known in only one species of fly, he explains.