A SUNSHINE Coast high school teacher needed surgery after being bitten by a wobbegong shark, but Shane Hilder believes his attack was a case of mistaken identity.

Mr Hilder told ABC Sunshine he was taking his 10-year-old daughter Molly for a swim when something hit his leg.

"I thought it might have been an adult body surfer underwater that banged into my leg, but I knew it was heavier than that," Mr Hilder told ABC.

"It had a lot of weight to it so I knew it was something big and that's when I jumped back and it bit me."
 

At the time, the Maroochy High School teacher was near a crowd of surfers about 50m from the shoreline.

Mr Hilder said he didn't blame the wobbegong, which he thought gave him a nip as a warning.

"It was an accidental bite," he said.

"He just ran into me and bit me to tell me to go away."

Wobbegongs  -- a type of carpet shark -- are known to bite at divers who accidentally step on, poke or touch them.

Their teeth are small but sharp, and can pierce a wetsuit. They are also able to grip on to whatever they bite.