At what size can you sex bristlenoses?

yhbae

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Aug 5, 2003
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I purchased 4 months ago at 1.5 inches. Now they vary between 2 and 2.5 inches. For some reason, one of them started to accelerate in growth and is the most aggressive one (i.e. chases away other bristlenoses near food). I'm trying to look for bristles but still not very noticeable. Hmm...

Do I have 4 females with one super aggressive one, or am I supposed to wait longer to find out if I have a mixed group?
 
hey dude, if you are talking about Ancistrus sp.(1) "Bristlenose Catfish" then they grow to about 12 cm, but if yo uahve a male, the bristles on the noses of htem should be noticeable by now. basically, if i were you i wouldnt be disappointed if you ahve 4 females, because you need more females than males. jsut go to the lfs and pick up a male, and your sure to be breeding in no time. the only other hting i can think of is if they are in with other cichlids, the brisles may have been eaten ff, i ahve seen this before, and it makes them look like females. if they are in their own tank, im sure htat they are all females if they have no bristles.
goodluck dude
Krusty
 
Yes, these are Albino Ancistrus, not sure of the exact sp. The largest one is around 7cm, and from what I have read so far, they are supposed to show some sign of bristles around this age, if it is a male... My LFS only carries the small 1 inch albinos so I'm not sure if I want to get 4 more just to see them turn into females again... :D

They are in a community tank so no other fishes dare to touch them - they are the most "aggressive" if you can call that at Ancistruses... :D

Grrr hopefully the largest one turns out to be a male... Still hopeful!
 
Grrr... all of mine are at least 2 inches, so does that mean I have 4 females?

Man, I am now really afraid now, just imagine getting 4 more 1 inchers and end up with 8 females! :D

Unfortunately for me, I don't have much of a choice since I want albino fries and I only found one ship who carries them and they are always 1 inch or less...
 
For what it's worth, I have a bunch of fish that were previously packed into a 55 (I think there was something like 30 fry, along with several adults, and a bunch of other fish as well). I only kept 4 of them, and added them to my 40, where there were 3 other BN--one large male, and 2 smaller young ones. The big male was the only fish to have any bristles, and the others ranged from less than an inch to about 3 inches. Now, about 8 months later, there are 3 very bristly boys, and 4 that still have either no bristles, or very small ones. Maybe most males will show bristles at 2 inches, but mine did not.
 
Hmm... that is very hopeful indeed... :D

For some reason, only one started to grow MUCH faster than the rest. She/he is much fatter too, chases away the rest when vegetables are provided. I was assuming this is the male and the others are females but the bristles are still kinda puny... And at 2.5 inches, he/she ought to show some by now!

OrionGirl, what was the size of your fish when your bristles (um, I mean you fish's bristle :D ) showed up?
 
Hmmm...I think the largest was about 3.5 inches when it started getting bristles, and they are now long and branching.
 
Hi

My two parents (bristlenoses) breed all the time, and I supply my local fish shop. He hasn't had to get any in for about 8 months now cos I'm over run with the little sweeties.

My nursery tank is full with babies rangeing from 0.5" to just under 4". the big ones are only just showing signs of their bristles. It seems to be that the ones that have a huge growth spurt in compared with the others and bully more always turn out boys, So it would seem as though you have at least one chappy in there but theres time for the others yet. Hold out cos I thought none of mine were boys and let them go as girls. when I kept them longer they then started to change.


Best of luck

Kim x
 
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