The fish belong to a family of rays, including manta rays and devil rays, that are known for their frequent and flamboyant jumping, though the habit remains poorly understood by scientists.
"There are some theories out there [about why the rays jump]," Cowen said.
"One is that they're doing it as a means to shake off possible parasites. It may be a communication among individualsthey slap the water, and that sound can be heard. People have gone so far as to say it's because of a love of life. I don't know."
(Read related story: "Giant Jumping Sturgeon Stir Up Mystery in Florida River" [August 17, 2006].)
But Cowen does believe that when the ray fell into the boat, it was as much a shock to the ray as it was to Bertakis.
"The fish didn't hit the water, so it's freaked out," he said. "It's flapping around, it's jumping around, it's struggling. It's a relatively large fish, and [Bertakis] is picking it up, [so] as the fish was thrashing around, it ran the stinger into him."
The encounter seems even more fantastically random, Cowen adds, considering the elusive, secretive habits of the spotted eagle ray.
Eagle ray stings are extremely rare, he explains, because the rays spend much of their time swimming, unlike the more commonly seen stingrays that rest on the sandy sea floorand often get stepped on.
"[Eagle rays] swim a lot more than typical stingrays, so you would not normally get them in a situation where they're feeling threatened. You're not stepping on them, you're not poking them, you're not biting them as a predator might, where they would have a need to use their stinger.
"What happened to Steve Irwin and what happened to this guy [yesterday] in particular was just a fluke."
The scientist stresses that stingrays only use their venom-tipped tails in extreme circumstances, and even then as a defensive reflex rather than as an attack.
"They're really quite safe," he said. "Particularly the eagle rays are very docile animals when they're swimming around."
As for the likeness that yesterday's event bears to the encounter that felled Irwin, there's nothing to it beyond mere, if somewhat uncanny, happenstance, Cowen says.
"We're not going to see eagle rays jumping out of the water attacking boaters," he said.
"If it happens a third time then we have to start worrying about it," he added with a laugh.
"But I really think it's a fluke."
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