Gravid Bowfin spawn in all the major areas of Monster Hunter Wilds, but this specific pond is one of the most reliable. And unlike the larger Monster Hunter Wilds Whopper fish, catching them is very simple - just twitch the line until they take notice, then press R2/RT the moment the Bowfin bites to reel it in.

Here's a list of Monster Hunter Wilds fish and where to find them, including the Goldenfish, Gravid Bowfin, Whopper, and Grand Escunite.

Being the first real fishing challenge in Monster Hunter Wilds, there isn't much information about how or where to catch a Gravid Bowfin in-game.