Which animal has the shortest weenie, and which is the longest?

The animal with the shortest reproductive organ is generally considered to be the male bumblebee. The size of its genitalia is significantly small compared to its body size. On the other hand, the animal with the longest reproductive organ is the barnacle. Some species of barnacles possess a penis that can extend to several times the length of their body, allowing them to reach out to fertilize neighboring barnacles since they are sessile (fixed in one place). These extremes illustrate the fascinating diversity of reproductive adaptations in the animal kingdom.