Siwik had already snagged about 20 silver carp, the invasive species known for jumping out the water. He threw his line out one last time hoping to catch another and quickly hooked a big one.
Siwik realized immediately by the way the fish took a deep dive and headed left it was likely the biggest he'd hooked all day. He didn't know, however, it would turn out to be the most unique fish he'd ever caught — a rare white and yellow bighead carp.
Bighead carp are normally dull grey in color.
"When I first saw it I had no idea what it was because all I saw was white and yellow and I was like, 'Oh wow!,'" said Siwik, a resident of Regan, Tennessee. "The only thing I could think of was, 'I can't lose this fish. So I just let it play out and tire out.'"
After about a 10-minute fight, Siwik, who was fishing from the bank, landed the fish and was even more amazed by its unique pigmentation after getting a closer look.
At first glance it looked a like a koi.
"Then I got a better look at him and said, 'Heck naw, that's a bighead,'" Siwik said.
The fish weighed 41.68 pounds and measured 4-foot-1 in length.
Siwik often fishes for spoonbill catfish and said the bighead carp fight similarly to that species.
"The spoonbills and the bigheads in my experience seem to love to go to the bottom or just take off and that's exactly what it did was just take off," Siwik said.
Siwik estimated he caught the fish in a depth of 5 to 6 feet.
It wasn't the only rare catch Siwik has made recently. Earlier this year, he caught a 200-pound alligator snapping turtle.
"They are super rare in this part of Tennessee and we let it loose because it's protected in this state," Siwik said. "My wife weighs almost 130 pounds and I can pick her up and walk from one end of the house to the other. I couldn't even get this dude off the ground."
Reach Mike Organ at 615-259-8021 or on Twitter @MikeOrganWriter.
This article originally appeared on Nashville Tennessean: Tennessee fisherman catches unique white and yellow bighead carp