How soon can bns be sexed?

My bn is probably about 2 inches long right now, and tiny bristles are visible on his nose. I know male bns get longer bristles than females do, but how soon does that happen? Is there any other way to tell males and females apart?

male

Yep Boy.

Usually around 5-6cm is when they start being sexable. Males develop - as yours have - bumps/stubble... I have not seen a female BN develop any small whiskers before 9cm, even then, it was only once i added another female to the tank - A show of 'top dog' maybe??

I have not been wrong yet with a BN & his 'stubble'

I have three baby albino bristlenoses that are now 2.3 inches long (6 cm) and there is not a bristle to be seen on any of their noses. Since it was posted above that their bristles should show by about 5-6 cm), could that indicate then that mine may be females? That would be great if they're all females as I already have two males and was hoping for females.

Big chances for females. The guys supposed show some already.
Unless they're super-slow developing males

female

Another way is to look for the reddish mark just behind thier eyes. Sometimes you can sex them at an early age this way. On my Albinos and Super Reds it is almost heart shaped and appeared long before the bristles. Males have a broader head than the females also.
At least this helps me sex them earlier.

Have Fun:D 

So i ordered some BN's and i asked for the largest possible male and female (basically just to be sure i got a male and female and not a male with little whiskers mistaken for a female or something) so they got in 6 3.5 inch plecs, 3 fem and 3 male, though they said it's no guarantee (they generally don't carry BN's-they do more out of the ordinary) but said that they were the most likely male and fem the vendor had for them. So my question is will it be very obvious when i go to pick mine out who is male and who is fem? I know they have like a 2 week thing that i can return if need be but i'd rather not if possible. I know it says here that it is obvious prior to this size, but how obvious will it be at 3-3.5 inches?

Very obvious. 3" = serious bristles.

it's still hard for me to tell male and female apart, i don't know what "a lot" of bristles looks like really

ok, go to my gallery, first pic (p3261290) is female;
3rd (p3121157) is the guy, he was about 3,5" at the time, but 3" won't have much less;
my avatar is 4,5"

grngito wrote:

Another way is to look for the reddish mark just behind thier eyes. Sometimes you can sex them at an early age this way. On my Albinos and Super Reds it is almost heart shaped and appeared long before the bristles. Males have a broader head than the females also.
At least this helps me sex them earlier.

Have Fun:D 

Anyone know more about this sexing technique? Red markings/shapes behind the eyes. I'd like to try it on my BN and see how accurate it is.