How do fishmen produce water when there is no water around? I was watching the fight between Luffy and Hody, when Hody tries to use the attack where he shoots water bullets (I think it's called Yabusame).

So I was wondering how he can produce so much water when there is no water around him? Is that some quality of the fishmen or am I missing something?

Here's the image from the fight.
As state on wiki, Hody's body under the influence of Energy Steroids can produce water, so he can make a drip of water even when he wasn't soaked


  After overdosing on Energy Steroids, Hody appeared to drip with water even though he wasn't soaked, suggesting that he'd been secreting it.


So I think it's just like sweat, but with greater amount of water