nannostomus eques aggression

[manini333]

hi, i have 4 nannostomus eques in a 24 x 12 inch tank and one is getting picked on quite a bit by the others. should i keep a pair in a separate tank or put more. how many would work in a 24 x 12 inch tank?

 

[Mike Wise]

Pencilfish are not true schooling fish although they do tend to gather together loosely. They are territorial, especially males. They are, after all related to the Erythrinids (predatory wolffish). If there is cover, like roots of floating plants like water sprite or water lettuce that they can hide in, there shouldn't be too much physical damage from aggression. Your tank can easily handle 24 specimens if it contains no other species.

 

[manini333]

great info, thanks. i'm pretty sure i have 2 males 2 females, because the 2 brightest most slender are seen flashing fins at each other in the middle of the tank then going to their territories. the smallest female who was the lonely inhabitant untill i got the other 3 gets gently nudged and draws calm attention from the males while she freely swims the tank. the other suspected female is the largest fish and is constantly pecked at the same spot above the anal fin and chased violently around the tank until she gets lost among the bacopa monnieri and wood in my tank. i have limnobium covering half the surface and 8 corydoras habrosus. i had read that aggression gets spread around evenly when you have more nannostomus, but after reading your post i think i should first add plants with broad leaves to give more mid to top water cover because the baccopa leave a lot of visible space in my tank. i had thought the fish would hide well in the slender growth of bacopa and limnobium roots but they see that female too easily.

 

[chris1805]

I have 7 of them in my tank which is 60x40cm mine are a bit agressive as well towards each other but no damage to fins or anything. Mine like to hide in the valisineria and the floating plants. They also really like a big root from the top of the tank to the bottom of the tank. They even live together at the top with 6 marble hatchers which is doing great.
Here is a general vid of my tank, but in the first few seconds you can see how mine do and how the top looks