camel bladders

Can bladder capacity be built up? Or is it innate?
When I was in high school chemistry classes, one of the (sensible) rules was "DON'T DRINK FROM THE LABWARE". Being (insensible) teens, my best friend Mike and I decided to ask if it was ok to bring our own containers and drink from them. The teacher consented, and in our (not-very) boundary pushing way we made a point of consuming these vast sports bottles full of water.
Chemistry was the final two periods of the day, and then I had to catch a school bus home... by the time I made it home my bladder would be practically bursting. (Being, as I said, an insensible teen, I would time the length of passing water with the stopwatch built into the side of my yellow "sports" walkman.)
So you know, mostly harmless juvenile shenanigans. But I wonder, could there be a benefit? So many of my friends seem to have teacup bladders! But my capacities are vast... holding urine among them. Do I have my dorky faux-rebellious teen years to thank? Or is it just one of those things?
(In retrospect I do suspect there are some dangers to pressing bladderly limits, so I'm not making any training recommendations but still)
Bruce the (malfunctioning) Animatronic shark in Jaws: