UPDATE 14 July, 2016: A similar behaviour was witnessed in 2013 by diver Brent Collins, this time off the coast of Guam. This clip supports claims in this article that the fish was not being eaten, and suggests that juvenile trevallies take to hiding under the bells of both living and dead specimens of this (yet unidentified) species of jellyfish.  

When bizarre photos of a fish "inside of a jelly belly" surfaced this week, they quickly made the rounds online. But after checking in with some jellyfish biologists, we found that these strange snapshots might not be quite what they seem. 

Image: Tim Samuel/used with permission

It certainly looks like the fish was eaten by the jelly (and many media reports have suggested this is the case), but what you're looking at is more likely the end of the road for the fish's jellyfish abode, not for the fish itself. 

"When I saw it, I was filled with amazement and curiosity," says wildlife photographer Tim Samuel, who encountered the strange pair last December. "I had never seen anything like it. It was so strange and unusual, and it was really interesting to see how it would move through the water. The fish propelling the jellyfish, but wobbling around, and being thrown off course." 

Image: Tim Samuel/used with permission

Samuel's description makes sense – and that's because we're looking at what is probably not a living jelly, but rather a segment of the animal's bell that has folded in on itself, the aftermath of the jelly being eaten by a sea turtle or some other predator.

Jellies don't shed pieces of their bells on their own, and the structure still appears in good condition. This suggests that the jelly probably met its end not long before Samuel came across his strange find.  

"As a surfer I've always had a love for the ocean," he says. "Taking photos of wildlife allows me to combine two of my favourite things: photography and the sea. My goals as a photographer are to generate a conversation and inspire people with all the beauty the ocean has to offer. I'm happy my photo has achieved this." 

Speaking with Australian Geographic, University of Queensland ichthyologist Ian Tibbetts identified the fish as a juvenile trevally, one of a number of fish species known to take refuge under the bells of passing jellyfish. It's a behaviour we've seen before in the juvenile shrimp scad:

It's possible that the trevally simply attempted to hide – invisibility cloak-style – inside the bell fragment, and became trapped when the membrane wrapped around it. 

"I didn't witness the entrapment," clarifies Samuel. "I just saw the fish already trapped inside the jellyfish."
Whether or not the fish managed to escape its gelatinous prison remains a mystery, but there's certainly a chance it lived to see another day.
For more amazing wildlife sightings, head to Samuel's Instagram page


Top header image: Daniel Slaughter, Flickr