Do you know a tough fish?

A little lighthearted here, but there was a time COG preachers were accused of spending too much time fishing. Now I think the complaint is too much time golfing. LOL

Truth fully I was taught to fish by a COG preacher. not my dad!

This comes up because a neighbor who lives on Lake Eustis in Florida, gave us some frozen fish. Some labeled perch the other not labeled. I cooked (based and deep fried) all of them. The perch (called Specks in Florida) were delicious, but the others were VERY TOUGH, a lot like a tough round steak. I was shocked, I have never seen nor heard of a tough fish.

My son said maybe Striper? We have caught and eaten fish from Key West to Alaska and have no idea what these fish were. The neighbor is a snow bird and is gone home so I will not learn for sure until next year, I am just wondering, do you know a fish that can be considered TOUGH? Thanks.....