bristlenose question

[Pooks73]

i have recently acquired 4 baby bristlenoses's. i'm not sure of the exact species, and i can't really get a good pic of them or i would post it for help. basically they have a black body with yellow spots and a yellow edging on their tail fin. i know, that doesn't help all that much. i need to get some pics!!!

anyway, my question is about sexing and bristle development. they are growing quickly, already about 1 1/2" from the 3/4" when i got them about 6 weeks ago. they are all fat and happy and eating away. two are obviously larger than the other two, so i'm beginning to wonder about their sex. how large do they have to be before gender can be determined? also, at approximately what size/age do the bristles begin to develop? i do not see any bristles on them yet, but it can be hard to see since they are still small.

thanks for any help you can give!!!

[Chrysichthys]

Identifying the species probably won't be easy, but they could be

Ancistrus dolichopterus

.

Males tend to be larger, and broader across the "shoulders" than females of the same age.

Bristles will likely start to appear when they are 2-3 inches long.

[Pooks73]

thanks for the info. i don't think that's the correct speces only because these plecs have yellow spots, not white. or will that change at they grow? the pics on the profile seem to show them as having yellow spots when younger.

also, any idea on the typicall growth rate of these guys?

thanks again!!!

[Birger]

I have some BN's that I have been measuring every 2 weeks for the last 3 months.Out of interest I started measuring when they were about 60 mm (just under 2 1/2 inches) TL. Every two weeks they would grow 7-10 mm (approx 3/8 ") with the dominant male of course showing the most growth.This is a group of six in a 30 gal. tank and fed tablet food and algea wafers and I have not really been power feeding them so you could probably get faster growth if you wanted to.

Birger