I found out three strategies to last probably until a million. I got 1200 and the image was not worth it cause the other images are a lot hotter.
1. (the biggest cheese) if you jump at just the right time you can force a food to spawn on you. The code in the game gives you your jump ability when you touch food, so this means you get permanent jump. When you touch stomach lining, you lose a little hp but the food can prevent you from touching it like a shell. You can be knocked out of the food if you aren't careful, so the strategy I found was to hide in the lower left portion of the stomach and press jump on quarter second intervals.
2. You can force other prey into a corner, because the game doesn't check if something is underneath you to give your jump back, only if something is touching your hitbox, you can permajump by forcing every other prey into the corner, but be aware as while you won't die, the prey will eventually.
3. While touching stomach lining hurts you, it's not as bad as getting in the acid. The right wall allows you to climb up to the top if you spam jump enough, and so if you ever find yourself in a position with a particularly sadistic pred who only eats prey, you can climb the wall to avoid the acid and wait for more food