Lake Macquarie residents are being warned to keep an eye out after a Morbakka Fenneri jellyfish was spotted in the region.
It’s thought to be a rare species of the Irukandji jellyfish and was discovered in the waterways at Mannering Bay.
While the risk is still low at this stage, Council is warning people to be on the lookout.
A sting can cause painful symptoms like nausea, vomiting, severe back pain, breathing difficulties and spasms.
For immediate treatment, vinegar can be placed on the sting but in more serious cases an ambulance should be called.