This thiaminse thing:
Thiamine, also known as vitamin B1, is a nutrient. It is important for health in fish (and humans).
Thiaminase is an anti-nutrient. It is detrimental to health in fish (and humans).
Unfortunately, many fish and crustaceans naturally contain thiaminase. It does not affect humans so much because we tend to cook fish, which destroys the thiaminase.
Fish don't cook. If fish consume too much thiaminase over time, their health can suffer. Some fish are more prone.
I seem to believe that datnoids are relatively tolerant, as river shrimp are part of their natural diet. They should just not consume it exclusively.
I do not know about tigrinus. They might be less tolerant, especially when young. But they are not allergic.
That is all.