A Horowhenua Star reader sent in a photo of some unusual jellyfish she found while walking at Waitārere Beach and is curious to know whether they are harmful.

She said the jellyfish looked like giant blobs of . . . jelly.

National Institute and Weather Research (Niwa) has a jellyfish guide put together by marine biologists and biodiversity scientists and, while they say it is difficult to determine from the photograph provided, it is probably Aequorea forskalea, which is not a true jellyfish belonging to the class scyphozoa, but the dominant medusa phase of a class of Hydrozoa (hydroids).

Most are tiny, but during this phase of its life the Aequorea is a giant among hydrozoan medusae and is the largest in our waters. Technically it stings, but the sting is so weak most humans don’t feel it.

Aequorea forskalea commonly appear when the sea temperature is slightly higher than normal. The species is found worldwide and it appears in New Zealand waters during warmer (La Niña) summers.

Meanwhile, the Ministry of Health has a guide about what to do if you do come in contact with an unknown specie of jellyfish:

• Get the person out of the water and reassure them.

• Act quickly to flush the stung area with sea water (or fresh water if sea water is unavailable) to remove the tentacles.

• Remove any remaining visible tentacles using either using your fingers (with gloves if available) or tweezers.

• Immerse the stung area in heated tap water for 15 to 20 minutes to deactivate the venom. Have it as hot as the person can bear without causing skin burns (and no more than 45C)

• Treat discomfort. If necessary, take pain relief such as paracetamol or ibuprofen according to package instructions.