Florida graduate student reveals wild shark discovery

• The team fished all night, and by dawn the weather started to deteriorate. Storms gathered.

They checked their lines again. One had something on it, but the experienced fishermen knew immediately it wasn't a tiger shark. Too sluggish.

• When the creature surfaced, it looked old — ancient, even. Blunt snout. Small pale blue eyes.

"I knew it was something unusual and so did the fishers, who hadn't ever seen anything quite like it in all their combined years of fishing," Kasana told FIU.

• She guessed it was a sixgill shark, known to inhabit deep waters. The waters off the Belize reef, some 800 miles southwest of Tampa Bay, reach 9,500 feet.

The shark was released, but Kasana texted a photo to Demian Chapman, her advisor and director of sharks and rays conservation research at Sarasota's Mote Marine Lab.

• He knew it wasn't a sixgill.

What they did: After talking to experts, they determined the animal was in the sleeper shark family — and due to its size, it was most likely a rarely seen Greenland shark.

• That's a virtually blind species of shark known to swim very slowly in frigid Arctic waters, feed on the carcasses of polar bears and live to 400 years — the longest-living vertebrate known to science.

• What was it doing down here? It's five o'clock somewhere?

Driving the news: The team's surprising findings were published this month in Marine Biology.

The big picture: The find — the first time a shark of this kind has been seen in western Caribbean waters off the world's second longest barrier reef — means there's a lot left to learn about these creatures.

What's next: One of the top experts on Greenland sharks gave the team four satellite tags to use in case they find another.