A prawn pound is an item released with Aquariums. It is a possible reward from opening a prawn ball (4% chance). It is a temporary item that lasts for 100 fish, and it increases chance of finding a golden fish egg. The length can be doubled by unlocking the Tier 3 Prawn Perks.
The prawn pound is functionally identical to the prawn penny, but lasts four times longer. Pennies and pounds may be activated up to a total of 1000 charges.
Prawn penny and pound charges are consumed whenever a fish with an associated golden fish egg is caught, even if that fish egg is already found and cannot be obtained again.