Despite their “old man” stigma, these sea creatures are, as one writer puts it, “ʜᴏʀʀɪfɪcally well endowed.” Seriously, they’re pretty huge. When ᴇʀᴇᴄᴛ, a male turtle’s ᴘᴇɴ.ɪs can grow nearly 50 per cent in length, 75 per cent in width and 10 per cent in depth. Considering some species of turtles have shafts that can be nearly half their body size to begin with, that is some pretty formidable growth.
2. Water boatman
The pen is mightier than the sword, and this tiny water bug’s ᴘᴇɴ.ɪs is louder than the rumblings of an African elephant. Or at least it is comparative to size. The water boatman’s ᴘᴇɴ.ɪs actually “sings” when it rubs up against the ridged portion of its abdomen, creating an underwater sound that would be the equivalent of standing 15 meters away from a ʜᴜʀᴛling freight train.
If barnacles seem boring, that’s probably because you’ve never taken the time to get to know them intimately. Not only do these hermaphrodites have ᴘᴇɴ.ɪses that can be up to eight times the length of their bodies (the longest relative to its body size of any animal), but the ɢᴇɴ.ɪᴛ.ᴀʟs evolve to suit its environment. As in, animals living in rougher waters will develop stouter ᴘᴇɴ.ɪses to withstand strong waves, while those living in gentle waters may develop longer ᴘᴇɴ.ɪses designed for maximum reach. Talk about going with the flow.
4. Bean weevil
We feel sorry for the female seed beetle (or bean weevil), because the ᴘᴇɴ.ɪses features on the males are the stuff of horror movies. These organs are complimented with sharp, hard spikes that absolutely inflict ɪɴjᴜʀies during ᴍᴀᴛɪɴɢ. The theory is that the ɪɴjᴜʀies stop the females from ᴍᴀᴛɪɴɢ again, ensuring the fᴇʀᴛɪʟɪᴢᴇᴅ eggs are the ones to survive.
There’s much to fear about these creatures, but it seems like we should add ᴘᴇɴ.ɪs to that list. We could get into it in our own words, but we feel the ɢᴇɴ.ɪᴛ.ᴀʟs are best described in this National Geographic article:
“Here are the highlights: it’s permanently ᴇʀᴇᴄᴛ; it sʜᴏᴏᴛs out like toothpaste from a tube; and it bounces back because it basically has a rubber band attached to it.”
These creatures, which along with the platypus are the last remaining monotremes on Earth, are anything but monotonous in the ɢᴇɴ.ɪᴛ.ᴀʟ area. That’s because the male enchidna has a ᴘᴇɴ.ɪs with four heads. Yup, four-headed ᴘᴇɴ.ɪses are a real thing. The science is still out on why they’re built this way, but one theory is that because the female has two canals, the ᴘᴇɴ.ɪs works like a double-barreled shotɢᴜɴ that fires two heads on one side and two on the other to best increase their chances of procreating. Science, huh?
7. Sea slugs
We’re fascinated by one particular species of sea slug found in Indo-Pacific waters, the chromodoris reticulata. These hermaphrodites feature the world’s only known example of a disposable ᴘᴇɴ.ɪs, which snaps off every time it’s finished ᴍᴀᴛɪɴɢ. Yet somehow, it’s ready to go again the next day. How, you ask? Apparently the ᴘᴇɴ.ɪs is roughly three centimeters long, but only a centimeter of that is exposed at a time. Bulking up the chances of procreating? These creatures happen to have three such ᴘᴇɴ.ɪses coiled up inside of them.
8. Female hyenas
Not only do female hyenas run the show when it comes to ᴍᴀᴛɪɴɢ, but they also tend to be more muscular and larger than their male counterparts. And, thanks to the presence of a hormone called androgen, they also have a ᴄʟɪᴛᴏʀɪs that holds their birth canal, and protrudes about seven inches from their bodies. Obviously, that makes her pretty well endowed.
9. Blue whales
Although there’s nothing particularly strange about the blue whale ᴘᴇɴ.ɪs other than the fact that the ɢᴇɴ.ɪᴛ.ᴀʟ slit is hidden during daily activity, it is the largest sized ᴘᴇɴ.ɪs on the planet and that makes it worth mentioning. Blue whale ᴘᴇɴ.ɪses can be anywhere from eight-to-10 feet long, and can weigh anywhere from 390 to 990 pounds. Yowza.
These (sometimes) predatory animals have a dual advantage when it comes to ᴍᴀᴛɪɴɢ, since they happen to have two ᴘᴇɴ.ɪses, or claspers, as their dongs are dubbed. It’s unclear why they have two, since they only use one at a time, but whatever the scientific advantage there’s no denying they’re pretty impressive to look at.
11. Harvest mice
Scientists theorize that rodents tend to have longer ᴘᴇɴ.ɪses because female rodents are quite promiscuous, so s.ᴇ xual competition is fierce. But by far it’s the harvest mouse that clocks in with the biggest member of the bunch.
“Everything’s relative, of course,” evolutionary biologist Steve Ramm said following a study published in American Naturalist on the subject. “So although big for its body size, the ᴘᴇɴ.ɪs ʙᴏɴᴇ in R. megalotis is still only seven to eight millimeters long. I don’t think the phrase ‘hung like a harvest mouse’ will be catching on any time soon.”