"It's only when you get the potential for hundreds or thousands of them to start biting you, for a long period, that you get the type of injury that Sam had", he told the BBC.
Sam Kanizay, 16, said he felt stinging on his legs while soaking them at Dendy Street Beach in Brighton, Australia, shortly before 6:30 p.m. after participating in a soccer match, The Independent reported. And they left doctors stumped. He tried to wash off the blood, but the bleeding didn't stop.
Sam Kanizay's legs after sustaining bites from the lysianassid amphipod.
Local swimmer Paul Duckett said he'd never seen anything like it, despite daily swims at the same spot for the last 16 years.
'You really need your feet for this game so we were advised not to go down there'.
Mr Poore said he was doubtful that this was a particularly aggressive strain of sea lice but suspected that there may be greater numbers in the area than normal - something that may be caused if a lot of dead fish were in the area.
It was most likely a combination of factors, including time of day and cold water numbing Sam's skin, according to experts. "I really just think [Sam] was in the wrong place at the wrong time, probably", she said.
Like any parent would, Sam's father, Jarrod Kanizay, wanted to look deeper into this extraordinarily freaky occurrence.
While investigating the trauma to his son, Jarrod Kanizay put meat in a net in the water and recorded dozens of sea creatures nibbling on the meat.
"We got him in the shower but as soon as we did that, the blood kept reappearing". There was also a massive amount of blood.
Kanizay is expected to be just fine, and the marine scientists who have spoken out about the incident suggest it was just a bit of bad luck. It's just food for them. Because it's a larger area it looks pretty bad. "He hobbled home pretty quickly".
Marine biologist Genefor Walker-Smith examined a sample collected by Jarrod and said the creatures are naturally-occurring scavengers, which commonly bite, but do not usually cause these kind of injuries.
Bloodthirsty sea fleas have special teeth created to shred meat.
In 2015 a father and son were bitten while taking a dip at Sandringham beach, in Melbourne's southeast.
"It's not a parasite I've ever come across", he said.
"If we didn't have them, we'd have a sea full of dead fish and dead birds", she said. They are not just an Australia thing.
The teenager "had to have really really cold, and it is for that that he has not felt", said Mr. Weir, who had already had scratches similar on the front after a diving in the night 40 years ago.