A Baptist University-led team on Tuesday said it has discovered a new species of box jellyfish in Hong Kong – and it's venomous.

The researchers said it is the first box jellyfish to be found in the city's waters and the species has been named Tripedalia maipoensis, after the family it belongs to and Mai Po where it has been found.

The creature is more than 10 centimetres long. Along with its 12 tentacles, it has 24 eyes.

The researchers have confirmed it is poisonous, but they are not sure how dangerous it might be to humans.

Professor Qiu Jianwen, who led the research team, said their discovery is exciting.

"Previously, we haven't had any records of box jellies in Hong Kong. And (they are) also very rare in China. There were only three records of box jellies in all Chinese waters," he said.

Qiu said DNA analysis has shown that the box jellyfish has different gene markers from other species.

Ocean Park said it has helped to rear around 30 of the box jellies and it might put them on exhibition in future.