We've seen some pretty weird things come out of the ocean recently. Glow-in-the-dark ninja sharks. A fish with legs. Gallon of Milk, the ridiculous bright-white whale. But none have been quite so swollen and quite so pink as this bizarre 'swellshark', encountered by fishermen off the coast of Mexico last week.

Identified tentatively as an albino swellshark (Cephaloscyllium ventriosum) - a species of catfish found in the Eastern Pacific Ocean - the fish has obviously been through some sort of trauma, judging from the photo above of what it should actually look like…

The fish was caught by Jaime Rendon, captain of the Dr. Pescado tourist fishing boat that operates in Cabo, on the southern tip of the Baja California peninsula in Mexico. 

"I was really surprised but what caused most impact were the eyes, so strange," Rendon told the Pisces Sportfishing Fleet. He described the fish as having "raspy skin, three rows of tiny teeth, and three gill slits on each side of the head". 

So… why so fat?

It's thought that the ballooning of the stomach is a defence mechanism used by the species where it bends its body into a horseshoe shape by grabbing its tail fin with its mouth. It then sucks a bunch of water into its stomach and inflates itself to twice its original size, which makes it much harder for predators to bite and swallow it.

swellshark2Jaime Rendon/Pisces

All that extra air causes the swellfish to rise up to the surface, but of course, all inflated things must de-inflate, so when it eventually lets all the air out, it sinks back down, making 'dog-like' barks in the process. 

So that's why it's fat, but why is it so incredibly pink? It's thought that this particular swellshark is albino, so perhaps the odd pink colouration has resulted from altered pigment cells in the skin.

The best part about this incredibly cool find is that the swellfish survived the encounter and was released back into the ocean by the Dr. Pescado crew to live out the rest of its life, fat, pink, and happy (we hope).

The photos have been sent to researchers for further analysis. 

"Alien Fish Mystery Solved - after studying the photos, the experts agree that the strange fish is an albino swell shark - still alive and well!" Pisces Sportfishing Fleet wrote on Facebook. "Thanks Jaime for the great story and for releasing this cute critter."