The only male marsupial with a pouch uses it to "tuck his junk"

I found an adorable new creature to obsess over! Meet the yapok, also known as a "water opossum" — the only marsupial adapted to an aquatic lifestyle. They are cousins to the more familiar Virginia opossum and resemble it, but have short, grayish-white and brown water-repellent fur, as well as cute white stripes on their faces.

Yapoks are semi-aquatic, web-footed (but only their hind feet, as their front feet have long, skinny fingers that are excellent for catching prey) marsupials that live along tropical rivers and lakes from Mexico to Argentina. Their webbed feet make them excellent swimmers, and their long tails help them maintain balance as they glide through the water in search of food. They are most active at night, are terrific climbers who build nests high in trees, and are beneficial to the ecosystem because they help control the populations of the fish, crustaceans, snails, insects, and small mammals they prey on.

It's wild enough that they are the only marsupial adapted to the water, but that's not even the most interesting thing about yapoks. What really blew my mind is that they're the only living marsupial where both sexes have pouches! When baby yapoks are born, they climb into their mother's pouch to nurse, so, like most marsupials, the females carry their offspring. The mom's pouch is also watertight, keeping the babies safe and dry as they move through the water. So what, you might ask, is the male's pouch for? Well, as SciShow explains, it's a place where a male can "tuck his junk." Yes, that's right; the pouch, also known as the "pars pudenda," appears to function, as Animal Diversity states, "to protect the male genitalia while underwater." That way, the male yapok's scrotum can stay nice and safe and dry and warm while he swims. And as a bonus, it also helps keep his sperm at the ideal temperature!

Cute and clever! What's not to love? Enjoy learning more about these curious marsupials in the videos I've included below!