Let's talk fruits, or devil fruits.
We've known for over a year that fruits respawn after their user dies, into a close fruit, but do we know that it has to be one kind of fruit? That if Kaku died near a bunch of apples, the next Girafe fruit would be an apple, and not the closest banana? I'm guessing that it has to be an specific fruit, because if else, everyone would carry tons of cytrus fruit around, to kill devil fruit users and capture their powers.
Maybe this knwoledge is just available to top scientist, because is the fruit (har) of Vegapunk's research, but eventualy someone would have realized "Oh, I killed the user of the fire fruit, and this mellon I've got turned into a devil fruit, with fire on it!". People die in this world, just not when we are seeing them. So, no one in a pirate filled world has happened upon on killing a devil fruit user while having fruits near and in his or her control? Considering that most battles must be at sea, and if someone boards your ship, you are in the losing side, and you must also have fruit in the hold, even with a devil fruit power, that ship is probably done for.
Or something like Brook's case, but if his fruit was different, the pirates attacked, took all the food and left them to die, so his power would have transfered to the closest ship or island with the right fruit?
Well, if I happened upon this secret, I'd keep it secret.
Acording to the wiki, and my own memory, we've seen 8 devil fruits in the manga and 1 more in a game. (I'll include him, because it was one of those designed by oda, and shares the same weird "pseudocanon" space that Shiki and Z share)
So, fruits and their counterparts:
Gum - Japanesse Melon (the weird green round one)
Bara - Pineapple
Soap - Western Melon? Avocado?
Girafe - Banana
Darkness - ??? Grapes? a giant berry? The leaves on top seem closer to berries
Axotol - Apple
Flame - Japanesse Melon (I think?)
OP OP - Peach
Vampire - Tomato
So, just one bite would transfer the power to the user, leaving the rest to be a disgusting fruit. Let's say that the Ball Ball (one of the weird marine captains) fruit is a Grape, with the Girafe fruit we saw that the bunch of bananas were the 3 of them had the power, so a grape bunch would also be filled with the power, so the conection remains, the grape bunch would be the same, if there was a lone grape who got the power, would it transfer back to it's source, be it a bunch or a tree? If this conection must be physical (as it makes sense), then a whole tree can become devil fruits for a moment, if it's the closest? Or maybe the fruit must be cut off but still fresh?
So, this conection, that there is in a moment multiple sources of the power, but once one is consumed, the rest will be useless, so did anyone try to sell the other 2 bananas, or something similar? The identification process include something more that "it has swirls, it has a weird aura, it taste like shit"?
TLDR: My conclusions on how the devil fruit transfer process work:
- An user dies, the power goes to the nearest compatible fruit, it "infects" every fruit that is still connected to it
- The fruit must be fresh and ripe, maybe cut from it's tree
- The fruit becomes kind of inmortal, until eaten, so it doesn't spoil while it goes on to the sea
- Or The fruit just becomes re-transferible, so if it destroyed, or just spoils, it transfers to the next available fruit
- The leftovers of the fruit, once eaten, spoil and rot very quickly (maybe that hour)