Why is careful observation during feeding time non-negotiable for aquarists keeping boxfish?

Answer

To confirm they are actually consuming food rather than being beaten to it by competitors

Due to their slow feeding style and disadvantage against faster swimmers, aquarists must confirm that the boxfish is consuming its share of sinking morsels, as they can easily miss meals.

Why is careful observation during feeding time non-negotiable for aquarists keeping boxfish?
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