A family of 11 are fighting for their lives after tucking into a dinner of one of the deadliest sea creatures.

The Souza family of Rio de Janeiro, Brazil, have fallen seriously ill after unwittingly cooking up and eating a puffer fish last week, the London Evening Standard reports.

A friend had caught the fish during a day’s fishing and the family thought it looked so tasty that they fried it up.

The puffer fish is considered the second-most poisonous vertebrate in the world, after the golden poison frog. It harbours a toxin 1200 times more powerful than cyanide, a drop of which can kill within 24 hours.

The Souzas became violently ill seconds after they took a bite of the meal. After one mouthful, they all began to vomit and lost the feeling in their face, arms and legs.

All of the family members, which included four children under the age of six, became totally paralysed.

“My husband was the first to say he couldn’t feel his tongue, then his face, and then his arms, Christiane Souza told Brazil’s RJ TV.

“Then his legs went dead and he couldn’t stand up anymore. It was terrifying.

“My brother-in-law was the same. He didn’t even make it out the door. We had to carry them out and rush them to hospital in a car.

Grandmother Maria do Carmo, who didn’t try the fish, said her grandson, daughter and son-in-law were all in a critical condition.

“We’re paying for a miracle, she said.

“We put the fish on the table in the yard outside and everyone dived in (sic). They were all saying how delicious is was.

There is no known cure for the poison, which eventually suffocates the victim while they are still awake, Metro reports.

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