AN INSTAGRAM model was bitten by a shark as she posed in the sea for a bikini pic.

Katarina Zarutskie, 19, was left with blood pouring from her arm after a sea beast took a chunk out of her flesh.

The moment the stunning nurse student was dragged under the water was captured in a series of pictures taken by her boyfriend's dad.

In one scene she is floating in the crystal blue water and the next she has disappeared in a cloud of froth as the giant fish attacked.

Other snaps show her climbing out of the water with her injured arm raised, and she later showed off the scars of the ordeal.

“I leaned back, and then that shark he came and he bit down on my arm and pulled me under," she said.

"I was pulled underwater for a few seconds and then ripped my wrist out of the shark’s mouth as fast as I could."

Katarina, from California, US, was posing in the Bahamas when she was grabbed by the nurse shark.

She added: "I am lucky to have my hand."

Katarina, who attends the University of Miami, had been on vacation with her boyfriend and his family.

Having grown up a surfer, she felt comfortable approaching the submarine predators.

But they were having none of it.

David Hocher, who owns the marina, told NBC: "These animals are considered quite docile but can and do bite on occasion.

"Normally when they mistake a hand or fingers for a piece of food."

Doctors have told Katarina she may have pieces of shark teeth in her arm.

She added: "I will forever have a scar.

"I am so fortunate that I still have my arm and my life."