Bukkit

Let's say I catch a big tuna; bragging is ok but what about cutting it into pieces and getting a large amount of food instead?

My suggestion is simple: put the special fish in the crafting table to get a number of Raw Fish equal to its weight (so, for example, a 15 libs Tuna can be turned into 15 Raw Fishes).

This would be OP and easily abusable, so big fishes should be very rare and more difficult to catch. For example, you can only get them in the Ocean biome; the fishing stick wears out much more; you lose fatigue (food level) while catching them; and so on.