The ache wasn’t too dangerous, he stated. The whipping sensation felt like a moist towel, and he has skilled worse stings from Bluebottle jellyfish, he stated.

Nonetheless, he thought it was finest to pack up the tent and return to their resort to observe the lash, which left clearly seen crimson marks, and ensure it didn’t worsen, he stated.

As a volunteer lifeguard for a few years, he would usually counsel the sting be handled with vinegar, he stated. However since there wasn’t any accessible on the resort, they had been pressured to improvise with one other acidic substance: His stood within the tub whereas his spouse poured soda down his again, he stated.

“The stinging sensation went away virtually immediately,” he stated.

Octopuses, that are often solitary animals, have been captured on video winding up and punching fish. Peter Ulric Tse, a professor of cognitive neuroscience at Dartmouth Faculty who studies octopus cognition, stated they “can specific what we might name aggression after they really feel threatened or after they really feel their territory is beneath menace,” he wrote over e mail.

“My guess is that the octopus right here is sending a warning which means ‘again off,’” he stated after watching Mr. Karlson’s video. “Octopuses will lunge or shoot an arm out after they really feel a fish, one other octopus or a human is of their house. I believe that is typically pre-emptive aggression, meant to sign ‘don’t mess with me,’ somewhat than aggression severely meant to hurt the ‘invader.’”

He recommended the whipping conduct would possibly even be “playful.”

Since sharing video of the octopus, Mr. Karlson has skilled the ups and downs of viral fame, together with receiving imply feedback from strangers on Instagram and cellphone calls from reporters around the globe.

His principal hope now, he stated, is that his story is taken with good humor and never used to sow worry of octopuses. He plans to return to the identical seashore and swim in the identical water, he stated.