Probably a daft question but???

I read somewhere that if male and female bristlies grow up in the same tank (not related) they wont breed...
Is it true???

I wouldnt think it was true, If they feel the need, they will do the deed

I did wonder as it sounded a bit hokey!
Having said that, being new to all this, you never know whats right and whats not lol!!!

I can tell you from personal experience, that a male and female BN who grow up in the same tank WILL breed. Years ago I bought my first little BN juvi.; it went into my 55 gal to eat algae. It did such a good job a month later I bought 2 more. One went into the 55 gal with the first and the other into a 29 gal. All were tiny and unsexable. The original one turned out to be female and the subsequent two turned out to be male. The pair in the 55 gal began to breed not long after the male began to show bristles and even today they keep that tank carpeted with fry. Thank goodness the local LFS is happy to get the offspring!