How to achieve "non-toxic level" of cultured puffer fish

Tetrodotoxin (TX) is a neurotoxin, which exists in halophilic bacteria, algae or shellfish in the ocean. The habit of puffer fish is to live on the bottom of the sea and eat fungi, algae or shellfish on the bottom of the sea. It is because of eating these toxic marine life and accumulating in the body through its own transformation that puffer fish produce tetrodotoxin. The toxicity of fugu rubripes is low, and the principle of poison control culture is to choose pure fugu rubripes and high-quality chilled fish bait. Wild puffer fish live on the bottom of the sea, and the algae and shellfish containing TTX on the bottom of the sea are the objects that puffer fish eat, while the cultured puffer fish do not sink to the bottom of the sea, so puffer fish cannot eat and produce fungi, algae and shellfish containing TTX. But it needs to be tested.