The Bowfin (AKA mudfish, dogfish, and grinnel) is a native North American fish. It is widely considered a "pest" because it eats young game fish and is thought to compete for food with adult game fish. It is not a hybrid; it is a genuine species and the only member of its family in North America.
The idea that animals should be destroyed simply because they compete with us or prey on animals we like better is completely anthropocentric and anachronistic. This was the basis of most of the disastrous predator eradication programs (more appropriately "pogroms") of the 1800s and 1900s. Bowfins are part of the natural environment and have every bit as much right to be there as fish that happen to be tasty or "put up a good fight." They've coexisted with the "panfish" for millions of years; if they were going to destroy them, don't you think they'd have done so by now? I hope you'll release any Bowfins you catch in the future and perhaps you'll educate your fellow fishermen to be more respectful of ALL native fish.