Adding fish dilemma ?

[Glenn407]

So the subject of pecking order is constantly brought up and that adding fish of the same species later is just asking for trouble. Right now my 50 consists primarily of about 8 each Glowlites, Embers, Harlequin Rasboras and one lone Serpae. I would love to add more, say a couple of each species yet I always hear that this will throw the established hierarchy into a turmoil. If this is true, which I have no reason to doubt, does this just last a couple days, weeks or what? It seems to me that unless you introduce a batch of a new species that are compatible with the other fish and the water parameters you are stuck with the setup you have until all of a species dies out. That if two of my Rasboras die it's just too bad for me until all of the Rasboras die of old age, that you can't replenish the group.

 

[Ichthys]

The species you have aren’t particularly known for having a strong pecking order. You should be able to add to their numbers without issue.

 

[Glenn407]

The species you have aren’t particularly known for having a strong pecking order. You should be able to add to their numbers without issue.

That would be good news. They do seem pretty laid back but who knows.

 

[Slaphppy7]

Serpae tetras can be nasty buggers, not sure I would add any more with the current stocking...but adding to the others should be fine

 

[Byron]

It depends upon the species. But it also depends upon the numbers of each, and of different species. And the tank size is a critical factor. Individual fish of a species may sometimes behave contrary to the norm for that species, just to add another wrinkle.

If you want species "x" then have a decent-sized group, replacing any losses as you go. The more you have initially, the less this is likely to be an issue anyway. Starting out for example with 12-15 rasboras is better for those rasboras than only having seven or eight. Numbers really do make a significant difference, we now know,

This is more of an issue with naturally-aggressive species, like many cichlids, and botine loaches. Most characins are laid-back, but the Serpae is a real exception to this. And given the fish mentioned in this tank, I would not keep this species anyway [in this setting]. The other mentioned species should be increased to at least 10-12, or preferably more. It really does make a difference to their overall health and well-being.

 

[Glenn407]

Thanks. That lone Serpae is the last survivor and unless it's doing something sinister at night it's well behaved. I see zero evidence of nipped fish etc. Good to know I can add. The Glolights are a fav by far. I don't know of another fish that can do a juke move like them at feeding time!

 

[Byron]

Thanks. That lone Serpae is the last survivor and unless it's doing something sinister at night it's well behaved. I see zero evidence of nipped fish etc. Good to know I can add. The Glolights are a fav by far. I don't know of another fish that can do a juke move like them at feeding time!

That's fine, just keep an eye on it. I have had the last fish of a species be extremely docile, and I have also seen the last of a species overnight become a terror to every fish, or certain fish (of other species).

 

[Ichthys]

I would guess the Serpae will be happy to see others, but I would add a few. Having 2 or 3 of a shoaling / schooling species often causes aggression

 

[GaryE]

Any group of fish in the wild is going to be fluid, with members coming and going. For fish that don't claim turf, you would have no problem. Rank would be sorted out in minutes. If you add one fish - no. Bad idea. But as long as a few go in, everyone will be distracted, no fish will be the focus of the group and peace will reign quickly.

 

[Byron]

@Glenn407 Just to wrap up with no misunderstanding, the lone Serpae may be no problem, or it may suddenly become a problem. Just keep an eye on it. And to do this, you sit without any movement for half an hour or longer in front of the aquarium and observe. If you move, the fish see it and instinct says "this is how we get fed," so the bad behaviour will not be evident. But sitting motionless for a time allows the fish to forget your presence and they get back to their shenanigans--or not, as the case may be.

My second earlier point was not to acquire more of the Serpae Tetra because generally speaking they are not that compatible with the slower and certainly much more peaceful fish you have. Increase those groups, but leave the lone Serpae and be ready to take action.

If for some reason you decide to enlarge the Serpae group anyway, you absolutely must have at the very least 12 of them, acquired together (introduced into the display tank at the same time). This is an aggressive characin, and keeping 12-15 usually means squabbling will be confined to the species. Though there are no guarantees. Even in groups this size, it is very common to see nipped fins on this fish, but that is its inherent nature and there is nothing we can do about it, aside from having 12-15 or more to hopefully maintain relative calm. But they must never be housed in with long-fin or sedate fish (gourami, hatchetfish, most cichlids, etc).

 

[Glenn407]

No worry Byron. Serpaes are the last fish I'd ever buy again at least to have in anything but a tank just for them.