A "perfect storm" of conditions has caused a bumper bluebottle season at Queensland's swimming beaches - and possibly brought giant rare bluebottles ashore.
University of the Sunshine Coast graduate research ecologist Letricia Delaney said multiple factors - including warm water, wind direction and huge numbers of holiday swimmers - had aligned ahead of the recent record number of bluebottle stings.
Ms Delaney said that bluebottles were "passive floaters" and their location was entirely determined by wind, waves and currents, with strong offshore winds driving many onshore in the past week, particularly on north-facing beaches.
Bluebottle stings have more than tripled across Queensland this season, with 22,282 people seeking treatment between December 1 and January 7, compared to 6831 in the same period last year.
Another 55 people were stung this morning; more than half at Mooloolaba on the Sunshine Coast.
Twenty-three people have suffered severe stings since January 1, with eight people requiring hospitalisation.
More than 2600 people required first aid on the Gold and Sunshine coasts as bluebottles swarmed beaches in record numbers across the weekend, AP reported.
Australian stinger expert Lisa-ann Gershwin said those severe stings could have been caused by rare giant bluebottles driven ashore alongside the more common smaller ones.
"It does have me scratching my head and wondering if this larger species is to blame," Dr Gershwin said.
"But it is very, very rare. We only get reported sightings every 10 to 30 years, give or take.
"It is much larger and it does come with severe symptoms which would require hospitalisation and are similar to Irukandji syndrome which is often mistaken for anaphylactic shock."
She said the giant bluebottle-like stinger was so rare it had not even been classified.
"It is of the genus Physalia, which is the same as the bluebottle and Portuguese man-of-war," she said.
"It is more like the size of the length of your hand and it has multiple main fishing tentacles compared to only one of the common little guy."
Dr Gershwin said the sting itself would "look like a normal bluebottle sting".
"But then you would get systemic symptoms like severe lower back pains, abdominal cramping, nausea and vomiting, these kinds of symptoms typically associated with anaphylactic shock.
"But the other symptoms like lower back pain, sweating, Irukandji symptoms you wouldn't get with standard old everyday anaphylactic shock."
A Queensland Surf Life Saving spokesman said lifesavers had not reported seeing any of the larger bluebottles.