Mosquitofish are efficient lovers

FOR humans sex can be just for fun. For the male Bahamas mosquitofish it is a matter of survival. It seems that these tiny fish have evolved genitalia that are adapted for the quickie.

Justa Heinen-Kay at North Carolina State University and her team caught fish from atolls in the Bahamas. Roughly half came from a group that is prey to larger fish; the rest had few predators.

Males with many predators had significantly smaller gonopodia – the modified fins used for copulation – with longer, bonier tips (Journal of Evolutionary Biology, doi.org/nqg). The small size lets them swim away faster, whereas the rigid tip boosts their accuracy. All in all, it makes for a faster, more productive session.

This article appeared in print under the headline “Impregnate me, and make it quick”