Nannostomus Marginatus

[seangee]

I mentioned in another thread that my stock of these is down to 3 in a community tank. These were purchased pre-covid so I am not too concerned about my ability to keep them .
I am reasonably sure I have 2 males and one female (but no guarantees )
I have now setup a breeding tank and I am almost ready to go.
My question is should I just move the 3 (or a pair ???) into the breeding tank or would it be better to buy a group of 10 and leave them in the breeding tank as a single species tank until they spawn?
I have read accounts that they are less likely to spawn if the group is too small.

What would you do?

 

[Innesfan]

The fewest or the most. I'd set up a pair or I'd go for a colony breeding. They are willing spawners. Among the most willing of the Nannostomus species. There are many populations which, I suspect, are about to be individuated as species. I've kept many and have never found one to be less willing to spawn than another. If you set up a pair, separate them for a while first.

 

[seangee]

The fewest or the most. I'd set up a pair or I'd go for a colony breeding. They are willing spawners. Among the most willing of the Nannostomus species. There are many populations which, I suspect, are about to be individuated as species. I've kept many and have never found one to be less willing to spawn than another. If you set up a pair, separate them for a while first.

Exactly what I was hoping to hear. Part of the reason for the exercise was to avoid spending money to replace fish , so I was planning to try with what I have first. I'll separate this weekend and start conditioning.
I have never intentionally bred fish before (although I did keep livebearers many years ago) so its re-assuring to start with something fairly easy.

 

[GaryE]

That's a fish that is almost impossible to find where I live. They were common for years, and then dropped off the radar completely. I have had an eye out for them for years, to no avail. Never take any fish for granted.

 

[seangee]

Seems to go in cycles here. At the moment they are readily available - although about 4x the price I paid for mine.

 

[Innesfan]

Exactly what I was hoping to hear. Part of the reason for the exercise was to avoid spending money to replace fish , so I was planning to try with what I have first. I'll separate this weekend and start conditioning.
I have never intentionally bred fish before (although I did keep livebearers many years ago) so its re-assuring to start with something fairly easy.

Lots of plants above and below and, if possible ph of 6 or below, though that's not an absolute necessity for this species. Ph-wise the species has a great natural range. There are several blackwater populations that thrive in Heckel Discus- sort of conditions with a ph in the 4s or below.

 

[seangee]

Lots of plants above and below and, if possible ph of 6 or below,

Slowly getting there. pH is no problem as I use RO. It's sitting at 5.5 with a little help from cattapa leaf, I'm frantically growing hygrophila and ambulia in pots as well as frogbit. I already have enough that I don't need to worry about cycling - even if I was to stock as a regular tank. But I will keep fertilising, lighting and growing for a couple of weeks. At the moment I am just leaving the cuttings to float free so it should be a mini jungle soon. I actually threw out enough cuttings from the other tanks today to completely fill this one - but not using these as I don't want to introduce snails. I have a very gentle trickle filter to ensure oxygenation.

 

[anewbie]

Are they a blackwater species ?

 

[Innesfan]

Are they a blackwater species ?

The Rio Negro and tributaries populations are. But there are dozens of populations in the massive South American range for the species that are not. And there are some pretty dramatic color variations among them. Probably why the splitters will be having a field day with them soon. I am told it is in the works.

 

[seangee]

Decided not to put it off any longer. I really wasn't looking forward to catching the little beggars, and my concern was justified. They are the smallest and most skittish fish in the well stocked and planted community. I managed to get there without dismantling the tank but abandoned my thoughts of separating the sexes and the 3 of them are now in here.

They are not the Rio Negro variety but I supplemented the catappa leaf with a couple of alder cones anyway.