Thanks to Brilliant for supporting this  episode of SciShow.

Go to Brilliant.org/SciShow   to learn how you can take your  STEM skills to the next level   this year! {♫Intro♫}. Finding love can be pretty tough  sometimes — even for a human on   the land.

But imagine if you lived in  the darkest depths of the deep sea. Down there, just finding another member  of your species can be next to impossible. Which is why some creatures have evolved some...  interesting strategies to pin down a mate.

For instance, allow me to tell you a deep-sea  shrimp love story. It begins with a sponge,   and two shrimp — and it ends in forever. The deep-sea sponge in this story is called  a Venus flower basket.

Like other sponges,   it’s a sedentary animal that uses its external  skeleton to filter food from the water around it. But this particular sponge almost  seems like it’s made of lace. Except, what looks like a delicate mesh is  actually spiky pieces of glass-like silica   called spicules.

The sponge weaves these  together to make its external skeleton. And as dainty as it looks, this structural design  is actually super strong. In fact, it’s what makes   it possible for these sponges to withstand  the extreme water pressure deep in the ocean.

But that’s not its only role. This  intricate glass skeleton also serves   as a home and a breeding ground for a pair of  deep-sea shrimp in the family Spongicolidae. Once two of these shrimp pair up,   they find a sponge and crawl through  the glass mesh.

Then, they settle in. Researchers think they likely hang out here  because passing food particles stick to the   spicules, so the shrimp can get a steady supply  of food. It’s a pretty great deal for a shrimp.

But this symbiotic relationship  works out well for the sponge, too:  . The hungry shrimp keep its spicules squeaky-clean,  and the sponge feeds on the shrimps’ waste. The only catch is… as the shrimp  grow bigger, they can’t get out.   They’re trapped behind the sponge’s mesh.

Which sounds a little tragic—but is  actually a good thing for the shrimp. As they evolved over thousands of years, they lost  features that would let them live independently. For example, their gills have shrunk  because their sedentary lifestyle   doesn’t require as much  oxygen as a free-swimming one.

Their shells have also become less spiny,   since the sponge takes care of  protecting them from predators. So it’s now impossible for them to live  anywhere but inside a sponge… together. Eventually, the shrimp pair has babies,  and these are small enough to squeeze out   through the mesh and set off in search of a  Venus flower basket sponge to call their own.

Then, finally, the original pair will die,   which will open that sponge up for new tenants  to settle in and continue their symbiosis. As for how the shrimp find their homes? Well, scientists think the  sponges’ spicules actually transmit   light from nearby bioluminescent creatures, so  as young shrimp couples look for a new home,   they’re attracted to these  glowing beacons in the dark.

This unlikely relationship has made it possible   for these shrimp to continue  to survive in the deep sea. And for some humans, it also seems to  have become a symbol of committed love.   In Japan, the skeletons of these sponges  are sometimes presented as wedding gifts. Because there’s nothing  like a deep-sea glass sponge   shrimp prison to say “until death do us part.” So, a big part of research that sometimes  gets overlooked is programming.

It’s not   necessary for all science, but knowing your  way around a code or two can come in handy. And if that’s a skill you want to learn,  you could try one of Brilliant’s courses. For example, they have a course called Programming  with Python, which teaches you one of the most   common languages with Brilliant’s trademark  explanations, quizzes, and hands-on demos.

Whether you’re a scientist by trade  or just think Python sounds fun,   you can find it at Brilliant.org/SciShow. And if  you sign up at that link, you can also get 20%   off an annual Premium subscription. {♫Outro♫}.