Final answer:
To store molluscan shellfish in a display tank, you need a variance from the local health department, should not remove shellstock identification tags, and having a self-cleaning filtration system is beneficial.
Step-by-step explanation:
In order to store molluscan shellfish in a display tank, you must obtain a variance from the local health department. This means that you need permission and approval from the health department to store the shellfish in the tank. Additionally, it is important to note that you should not remove the shellstock identification tags as required by law. These tags help to track and trace the shellfish to ensure their safety and quality. Lastly, having a self-cleaning filtration system in the tank is beneficial as it helps to maintain water quality and minimize the risk of contamination.