What’s really going on here?
Underwater photographer Tim Samuel was in the water off Australia's east coast with a friend when they came across a strange sight: a living fish that appeared to be trapped inside of a slightly larger jellyfish.
According to a report by AFP, Samuel had considered whether to "set the little guy free", but ultimately decided to "just let nature run its course".
The bizarre and incredibly rare image has gone viral, garnering more than 2 million online views.
So what’s actually going on in this photo?
Jellyfish experts were unable to identify the jellyfish with certainty, but a likely candidate is a box jellyfish. Box jellyfish use venom to prey on fish.
"They evolve to kill prey instantly," Luciano Chiaverano, a post-doctoral researcher at the University of Southern Mississippi, told CBC. "This might be a case where the prey is too big to kill it right away, so the fish might have some time to swim around inside."
The fish does appear to be in the jellyfish’s stomach. However, box jellyfish would normally eat prey a third or quarter the size of their bell, making this fish an unusually large target for a box jellyfish.
One of the photos shows an opening near the front of the bell, which Chiaverano says is not typical of a box jellyfish and may be an injury from the fish trying to escape.
The fish is also a bit of a mystery. Experts have not been able to pin down its exact species, but Ian Tibbetts, a fish biologist at the Centre for Marine Science at the University of Queensland, told Australian Geographic it might be a trevally.
Trevally are known to hide under the bells of jellyfish when they are young, and this one may have simply ended up inside of the jellyfish by accident.
And, of course, there is always the possibility that the photo is fake.
You might also like: The Science Behind This Stunning Frozen Tea Photo