Researchers prepare to dissect 'Frankenfish' 0
The northern snakehead. (Geoff Lister, 24 hours)
Off with its head - researchers at Simon Fraser University are expected to slice up the 'Frankenfish' found at a Burnaby pond last week to find the extent of the invasive northern snakehead's threat.
"And pull it out of its cranium," said biological sciences grad student Corey Phillis, one of the experts tasked with dissection. "We're going to take tissue samples, gut content samples, ear bones to age the fish, and find out what it's been eating and where it's been."
The most likely conclusion is that the three-quarter-metre long fish, weighing 3.32 kilograms, was released as a pet or from a fish market. However, researchers can't yet rule out the small chance that the predator - a fast-breeding, invasive species at the top of its food chain - was bred in the wild.
"That would suggest there are others out there, that there's a population or individuals," Phillis said of the worst-case scenario.
"This is the first discovery of a snakehead while in Canada, as far as we know. Where it has become established is the eastern seaboard of the United States. It's become a real problem."
By comparing gut content and tissue samples, researchers can identify whether the spineless creature's food in its last days - believed to be goldfish, koi and other small fish in Burnaby Central pond - is the same as what it's eaten in past months.
An "otolith" bone analysis can further determine the type of water it's lived in throughout its life.
"It's an ear bone. It grows like trees and tree rings, laying down concentric rings, so we can count the rings to get a sense of the age of the fish," Phillis said.
"Each ring that's put down reflects the water history and the food they've eaten at the time. We can look at the early rings and see the water they were in when they're young."
Until last month, the species was relatively unknown by the general Lower Mainland public. That is, until a Burnaby resident spotted and videotaped it - generating a massive fish hunt.
But even if there is a population out there, Phillis said the public shouldn't be overly worried for their pets' safety. Rumours of similar fish swallowing mammals whole are likely unfound.
"The Hollywood image of it getting up, crawling out of the pond and walking into your bedroom is a little far fetched."