Currently we are still looking into if it's possible to add aquariums.

There are no plans to add food that uses big fish as an ingredient at the moment. Creating a new meal that offers incredible buffs would in turn have an affect on the balance of battle, so we have to look into this type of thing carefully.

We're currently looking into turning fish into furnishings and adding other achievements for Big Fishing, so please hang in there while we look into these features.