JACKSONVILLE BEACH, Fla. -

A 44-year-old Westside woman wading in thigh-deep water at Jacksonville Beach Tuesday morning was bitten on the foot by a shark.

Mihaela "Mimi" Cosa, who was at the beach with her mother, was bitten just before 11 a.m. near 34th Avenue South. She was taken to Baptist Medical Center Beaches, where she was treated and received 21 stitches to close her wound.

Cosa told rescuers she didn't see what bit her -- she just felt something bite and shake her foot. She said it felt like knives slicing through her foot. Medical personnel later confirmed the injury was from a shark bite.

Stitches on foot for shark bite “I was just standing, and I felt the bite, and it didn’t want to let go,” Cosa said. “I don’t know how big it was, but I felt that he didn’t want to let go.

"I finally turned and I lifted up and I saw the skin hanging.”

Cosa said she was able to flag down beachgoer Frank Costantini, whose dog "Ozzie" was splashing nearby. He helped her out of the water and called 911.

"I thought it was a jellyfish or sea urchin or something like that, typical, but once she pulled it out of the water it appeared to be a pretty bad shark bite," said Costantini. "It was pretty nasty, actually. Maybe 6-8 inches in radius.

"I'm not a fisherman, so I don't know how big of a shark that translates to, but probably at least 3-4 feet. Pretty severe wound."

Blood on beach Cosa's bloody footprints could be seen in the sand for a while after she had been rushed to the hospital.

Costantini, who lives just a few hundred feet from the shore, said what he saw Tuesday was unlike anything he's ever seen.

"I'm in the water every day, surfing or boogie (boarding), just going out there swimming, playing with Ozzie," Costantini said. "It's pretty troubling, it's disconcerting when you see it in front of you. You hear about it, it's very rare, we know that. It would never prevent me from going in the water, but it still kind of shakes you up a bit."

Experts believe the shark that bit Cosa might have been a 3-4 foot dogfish shark or sandbar shark, which tend to swim in shallow water.

Cosa will have to return to the hospital later this week for a check-up. She said she still can't feel her pinky toe, which is something doctors told her could require surgery.

“I hope I don’t (permanently) lose any feeling in my toes," she said. "We’ll see what happens.”

Cosa said she's focusing on healing now and warns others to be mindful at the beach.

"Guys, be careful out there, especially the kids, because they’re helpless, they can’t realize it’s so close," she said.

The captain of Jacksonville Beach Ocean Rescue, Robert Emahiser, said there are some precautions you can take to stay safe.

"If you have any open wounds, we don't recommend swimming," Emahiser said. "Or if it's dark. We don't recommend swimming at night because sharks like to eat at night."

This is the first reported shark bite of the year in northeast Florida. There were three last year.

But the attack didn't deter some people from going in the water Tuesday.

Michael Kesslar said he went to the beach to try out his new surfboard.