A barnacle's penis is long enough to reach his mate 8 body lengths away without moving, often weaving it among others nearby.
Living fixed on one spot has it's disadvantages. It is more difficult to find a partner to mate.
The barnacle has overcome the problem in a really spectacular way.
From its shell the male barnacle projects a penis so huge it is many times the size of the owner.
The barnacle's organ finds its way through the gaps between its neighbors in search of the ideal mate.