When graphic images of a teenager's bloodied feet were published Monday morning in Australia, it sent shockwaves among the country's beachgoers. On social media, some vowed they would never swim in the ocean again.
Sixteen-year-old Sam Kanizay arrived at a Melbourne hospital on Saturday with his legs bleeding profusely. Photos taken at the scene show Kanizay sitting in a hospital bed while the lower parts of his feet and legs have turned almost entirely red from his wounds.
The teenager had been standing in the water after playing soccer. His legs were sore and he had hoped the cold water would help him feel better. He claims to have felt a numb, tingling sensation, but he chalked it up to the frigid water, telling Australian newspaper The Age, "I wasn't really thinking about being eaten."
Doctors told local outlets that Kanizay has been bandaged, checked for parasites, and given antibiotics. At the time of this article's publication, doctors had not commented on his condition, saying it was too early in the case.
Since news of the teenager's injury, a flurry of speculation has arisen on just what exactly nibbled on Kanizay's flesh.
Sea lice were initially thought to be the cause. The name is broadly used to describe small external, parasitic crustaceans that feed on skin and blood or the larvae of jellyfish. They're more commonly found attached to fish and large numbers can cause severe damage on fish by opening wounds. Sea lice plague beaches around the world from Australia to Florida, where they frequently wriggle inside bathing suits, causing little more than an itchy rash.
Searching for answers about his son's mysterious injury, Sam's father Jarrod Kanizay returned to the same beach spot where his son was bitten. Wearing a wetsuit, the elder Kanizay used a pool net and pieces of steak to fish out thousands of critters.
Skin-crawling video shows amphipods, also referred to as sand fleas or sea fleas, gnawing away at the steak used to lure it from the water.
Jon Norenburg, a research zoologist and chair of the Department of Invertebrate Zoology at Smithsonian's National Museum of Natural History, explained that confusing the two animals is a common mistake.
"Mistaking amphipoda as 'sea lice' is a perpetual problem," said Norenburg in an email with National Geographic. He explained there are hundreds of species found all over the world. Most amphipods are herbivores while others are omnivorous scavengers and "some non-parasitic ones are particularly fond of blood if available."
Marine scientist Genefor Walker-Smith examined the critters captured by Jarrod Kanizay, confirming that they are in fact sea fleas and not sea lice. She believes this proves fleas are likely the culprit.
What Attracted Them?
In an interview with Australian outlet The Age, Walker-Smith theorized that the amphipods were attracted to a cut on the teenager's skin or that he was standing near a fish carcass that had already attracted the flesh-eating creatures.
According to Walker-Smith, these fleas are typically abundant in the region where the incident occurred. She wasn't surprised the boy's father was able to catch so many by sticking a piece of meat in the water. Had Kanizay been moving through the water, it's unlikely the amphipods would have been likely to stay attached to his skin. They typically scavenge on dead fish.
The severity of Kanizay's injury was likely caused by the fact that he intentionally stood still to help ease soreness in his muscles. Some researchers have theorized the amphipods released an anti-coagulant as they bit the teenager, a reaction sometimes seen in bites from leeches and other species of crustaceans.
Norenburg remains skeptical that this is the case. He had never heard of any report that this species of amphipod was capable of causing this reaction, suggesting tests on Kanizay could show a predisposition to poor blood clotting or a particularly bad reaction.
While it's likely the sea fleas were the culprit, there's still room for doubt. The video only proves that sea fleas can frequent the same beach at which Kanizay was bitten.
"We’d need to have seen or caught them in the act on the teenager’s legs," said Norenburg.
In an interview with the New York Times, University of New South Wales associate professor Alistair Poore expressed room for doubt, saying, "You can attract a lot of animals in the sea with raw meat."
In 2015, a father and son experienced a similar but less severe injury when soaking their feet at the same beach. Like Kanizay, they claimed to have not felt any pain, only realizing they were bleeding when they left the water. When hosing their feet off, they noticed "tadpole-like creatures," a physical trait more consistent with sea lice.
A spokesperson from Australia's Department of Environment, Land, Water and Planning said sea fleas were a healthy part of the ecosystem but can be avoided by wearing a wetsuit, protective footwear, or not standing still for too long.