Nature is often weird. But sometimes, it’s REALLY fucking weird. I give you the pearlfish:

For those of you who can’t watch the video (though if you can, you really should)… Adult pearlfish are long skinny fish that live in open habitats. In order to not get eaten, they need to find a suitable place to hide. The problem is, they tend to live in places that are missing the typical hiding places like rocks and corals. They are, however, surrounded by lots of large sea cucumbers…so they hide by swimming up a sea cucumber’s butt and living inside of it. Most don’t harm their hosts, but some are parasitic, nibbling away at the sea cucumber’s gonads for nourishment.

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