Will Sampson and his friend went out for a full day of fishing in the Toronto Harbour on Sunday, and reeled in something unexpected.

“We were just rolling along. Got a couple [of pike] right off the bat, and as we were jumping around to spots, and when this fish hit–like judging by the weight and how it hit–I can tell it was a good fish,” Sampson tells CTV News Toronto.

“I just assumed it was a big pike, obviously.”

As Sampson reeled in the fish, he initially thought it was caught in the line with how much weight there was. Then he noticed what colour it was.

“Once I saw it was a muskie, my knees immediately became like jello. They just, like, buckled,” he said.

will sampsonA muskie, formally known as muskellunge, is a type of fish related to northern pike, and is typically a light silver, green or brown colour with stripes. The northern pike tends to be darker with lighter markings.

Sampson estimates the catch was 43-and-a-quarter inches and weighed just under 20 pounds, though he adds he didn’t have the necessary equipment to safely weigh the fish. While it’s a decent size, he notes muskies can reach the mid-50-inch range.

“We knew it was a unicorn like obviously there’s muskie in Lake Ontario, [but] in Toronto Harbour it’s super unheard of,” Sampson said, and later added you can typically find bowfin and the occasional walleye in these waters

Sampson, a sporting fish guide who says he has been fishing his entire life, tells CTV Toronto he has caught muskie before, but this is the first, ever, in this particular area.

He couldn’t pinpoint why there was a muskie in the Toronto Harbour, but notes there are a lot of them at the mouth of the Niagara River and at the other end of Lake Ontario, near Kingston.

Muskies once thrived in the waters surrounding the Toronto Islands about 200 years ago, according to the City of Toronto.

“After the arrival of Europeans, a host of changes resulted in the destruction or deterioration of fish habitat,” the city’s ‘Fishes of Toronto’ guide reads.

“A total of 15 exotic fish species were either intentionally introduced for food and recreation, or invaded through navigational canals or ballasts of ocean-going ships. Today, populations of most native fishes have declined dramatically and 10 species have disappeared entirely.”