I'm not sure you can over feed a bichir they will sometimes do something called stomach packing where they will actually compress the food in their stomach to make more room here is an excerpt from a sticky in the bichir forum here on MFK about bichir behaviour
https://www.monsterfishkeepers.com/...pterides-and-the-purposes-behind-them.223047/
Stomach packing:
This behavior is seen after the fish appears to have eaten its fill. When the fish's belly begins to show fullness, you may observe it bend it's body from side to side once or twice, using it's muscular body to adjust the food in it's stomach to allow for more space, the same way you would over-pack a suitcase.
In nature:
Being opportunistic predators in their natural habitat, bichirs need to eat all they can when they can. Because they use a lot of muscle to swim, they have a high energy cost to move around and hunt.
If the fish happens upon a large meal, either a fish carcass or some other chance opportunity for a large meal, the bichirs make the best of it by stuffing in as much food as they can.
In the aquarium:
Only the bichirs that are well settled into the aquarium environment, with voracious appetites will display this behavior. Because they don't need to work as hard to get their food, they may become obese if the aquarist does not control how much they are fed daily
