can merman even eat fruits?
I can't think back to any devil powered one.
I think that they negate devil fruits since they are cretures of the sea themselves.
edit: check ch69page08. they say that Arlong is as strong as Jinbei, that's not so tough. I can proove it with science (
it works, bitchs):
Beating Arlong boosted Luffy's bounty to 30mil (his previous bounty was less than 10mil). beating Croc gave him 100mil (70 more), and beating Rob Lucci jumped him to 300mil (but we should also take Enel into account for bounty exp). and luffy still didn't get any bonuses for beating up Moria.
Luffy now is ten times the pirate he was when he beat Arlong. the crew is whooping almost 700mil in bounty (300+100+80+79+44 = 600? and then there's brooke, Ussop, Nami and chooper, who give another 100 mil), which is almost 20 times the bounty they had when fighting arlong.
even if arlong wasn't roughly as strong, but only the first mate (and an extraordinary strong one, like Zoro) the math is still against Jinebei (Zoro has one third of Luffy's bounty, so Jinbei should get around 90mil, which is pathetic next to the SH crew).
the math works, sort of, well, if you agree to my terms and subject to my calculatuions and choose to accept my explanation.
still, unless Junbei reached a massive power up (or what Yosaku said was very, very, very not true), I don't see a way for him to win. or for anyother shishibukai (maybe MIhawk, on a 1vs1 fight with zoro)