The wide-bodied pipefish of Aotearoa New Zealand is a unique species that challenges expectations when it comes to mating behaviors. Unlike other pipefish species, where males carry developing babies in pouches, the wide-bodied pipefish has females with a significantly wider torso and brightly colored stripes. The reason for this difference in body shape remains a mystery.
To understand how females use their unique body shape during interactions with other females and males, researchers conducted observations in aquariums. Surprisingly, it was found that males initiated courtship displays with females most of the time, using comical wiggles. This was unexpected considering the female’s ornamentation. Normally, the sex with more ornamentation leads the courtship display, but in this case, males were more active in making decisions about who they wanted to court.
One possible reason for this behavior is that males are selecting the most fecund females, those with the most available eggs, as they are responsible for caring for the developing embryos. This differs from what is known about other pipefish species, where females typically initiate courtship and males reject some females.
This research is just the beginning of understanding how wide-bodied pipefish males and females interact. Further studies are needed to explore whether males court females in groups when there are more females than males, and vice versa. Understanding these unusual fish behaviors contributes to our knowledge of mating behaviors in other species and challenges our expectations of the natural world.
