Behold: the Damselfly penis.
Damselflies are interesting insects as far as the evolution of sexual reproduction. Males will grip onto females for hours during copulation to “protect” the females from other males.
Perhaps more interestingly, the damselfly penis has a neat little morphological adaptation visible in the above scanning electron micrograph that allows the male to manually scoop out the sperm of previous males from the female reproductive tract. From an evolutionary perspective, such an adaptation ensures that the successful male’s genes only are passed onto the next generation, improving his reproductive fitness.
Image Credit: Science Photo Library