Seattle-native Keith Magnuson thought he had spotted a shark while waterskiing along the shores of Lake Washington. As it turned out, he had happened upon a dead sturgeon floating belly up measuring an estimated 8 feet long.

According to The Seattle Times, the University of Washington School of Fisheries has the dead animal tied up to a post until state wildlife officials can come take a closer look.

"It is not a common fish to find in the lake and rather unique," Annette Hoffman, a state Fish and Wildlife biologist, told the Times.

And while decent in size, Hoffman says it's not the largest she's ever seen, recalling the discovery of another back in 1987 that measured 11 feet long and weighed 640 pounds.

More recently, a sturgeon just over 5 feet was caught in 2005 by a University of Washington research boat.

Hoffman explained that the sturgeon community migrate up and down the Columbia River, while local sports anglers hunt them down near the mouth of the Snohomish River.

Since they live in deepwater, they are not easy to spot.

Older than the dinosaurs, sturgeon belong to one of the most primitive groups of bony fishes that have survived since the Mesozoic era back between 65 million and 230 million years. And although some characteristics have changed over time, sturgeon are essentially the same tody as they were millions of years ago, according to New York's Department of Environmental Conservation.

And while they differ in size depending on their species, some are capable of reaching nearly 20 feet and 2,500 pounds. In the western United States during the 1700s, sturgeon grew as large as 1,500 pounds and commonly lived over 100 years.

All told, there are 26 species found worldwide, though they only reside in the Northern Hemisphere. Today, most sturgeon populations are protected and regulated in order to aid their lagging numbers.  

To see a picture of the sturgeon recently discovered in Lake Washington, click here.