Unraveling the Secrets of Extended Pairing!

The average #pairing duration for each age flies was ~39 minutes for 3-day-old flies, ~33 minutes for 4-day-old flies, ~32 minutes for 5-day-old flies and ~26 minutes for 6-day-old flies.

Clearly, the duration varies with the #age of the mates, i.e., with older flies engaging in shorter pairings.

Age may influence the quality of #males #sperm and #female choosiness in #mating. Whether this connection between pairing duration and age is a result of flies’ bodily constraints (e.g., less energy) or adaptive strategies (e.g., aging) employed by male/female remains unclear. It also raises the question of whether a specific sex hold #control over the pairing duration, e.g., do males use their #hooks to hold females during pairing, with younger males having more energy for such interactions?

One subsequent question arises: Does a longer duration of pairing imply a greater transfer of sperm from males to females?

According to Manas et al. (2023), the answer is surprisingly: #No.
The number of sperm found in the female’s body (after dissection/cutting up) is neither related to the age of male, nor with their #size. This also means that, enven though #largerfemales and smaller males engage in longer pairings, males transferred the same number of sperm as their bigger peers!