Hey, I just caught what I'm fairly sure is a western Ribbon snake two days ago. He's only 5 inches long and very thin so he can't eat large things yet. He did eat a minnow I gave him yesterday, but then it turned out to have been a flathead which I'm now aware can be harmful. Since I live in the south I have a lot of family members that go fishing. Often they catch shrimp, flounders, and other gulf fresh or brine water fish that could probably be cut up into steaks until he gets bigger, but I'm not sure which fish have thiaminase other than catfish, goldfish, and flathead minnows. My local pet store doesn't carry guppies or any other species of minnow, but I currently do have a frozen flounder that I'm never going to eat, so would that be alright to feed him with?