Why are my Silver Dollars so f***ing tense ?

[Ansorgii]

Hello everyone, sorry for swearing in the title, but I can't think of another way to fully express my frustration.

I have a group of 6 Myleus Rupripinnis Luna with about 11-12cm Diameter. They haven't really grown since I bought them out of a smaller tank a year ago and I dont think they will anymore. For the first few Months they were like all the other dollars I kept so far, not the most calm, but unless sth. big happend they just stayed under plant cover. And when fed they came out and ate directly under my Hand or from the surface.

But as of late, if anything happens, they start panicking through the tank until it foams and carry along all other tankmates. If I wear anything dark against the white walls I cant feed any of my not stingray fish since they are to nervous or panicking. Both the Silverdollars aswell as the other fish end up hurting themselves, which is sth. I really dont want.

The Dollars only start eating if I leave the room or stay still long enough, but one movement of my Hand and they are already in the corner. If they werent my favourite Tetra I would have thrown them out already.

So what has changed in my Tank ?

One big change was that I lowered my Stock. I removed 3 other dollars, all Flagtails but one since they were to busy trying to dominate each other, my black arowana and my Tiger Datnoid.

The only added fish were 4 (5) Cichla, of which I sadly lost one when the Dollars began to panic again and he broke his own spine in that panic. They do tease the Dollars sometimes, but they do not really care, at least when I was watching them.

Water parameters all stayed the same (28°C, ph ~7, hardness in the middle, nitrat 5-15, nitrit 0), the Tank setup hasnt changed either.

The Overall Stock is besides the 6 Dollars is:
1 Flagtail
4 small Cichla
4 baby Stingray
1 black Hypselecara (calmest fish I know)
And a few small L-Catfish

All in a 2m tank, which I know is to small in the long run, but as of now still enough. (Bigger will be finished soon)

Do you guys have any idea what I can do to make them calmer again ? Or should I just give them away to make the life of the rest of my fish easier again, which is what I am propably going to do if it doesnt get better soon.

I heard adding large calm fish helps, but I cant tell if there is any truth behind that, and adding new fish is always a risk.

Thanks for any replies in advance

 

[tlindsey]

removed 3 other dollars, all Flagtails

Possibly this caused the change in behavior.

 

[FJB]

My experience is limited to Metynnis dollars, but I suspect it apples more generally. Often, changes in the ‘troop’ such as removing or adding fish messes up the stablished dynamics. Often it is temporary but it can take a while. I once added 2 much younger dollars to a formerly calm group of full adults that became skittish in a new tank, and they went back to being chill. It appeared the small fish were ‘insignificant as threats’ (gender or size), but all fish had some interest in checking them out, bringing them back into the open.
I suspect each group is unique, depending on gender ratio, age and other parameters. Good luck. I hope you don’t need to rehome them but if you still want to, please talk to me.

 

[Ansorgii]

Thanks for the replies so far. I removed those 3 others, some Torquatus variant, quite a while ago (6 Months). So if that messed them up, it needed quite a while to affect them.

The Flagtail removel happened 2 weeks ago. Maybe after removing them, since they constantly stired each other up, the fish got more sensitive due to the tank finally being calm. And now, whenever I enter the room, its to much for them. However, they already have gotten a lot more tense before, so I dont think this is the only reason.

Another thing might be that the tank is in its own room, so me entering it is the only thing they ever see outside of the tank, and since its a small room they will not see me comming from far. The new Tank will have the same issue. And they got more tense over tine since they were "trained" to be calm in the previous tank.

F FJB I live on a different continent, so sadly I can't give them to you. In my area there are only few and cheap people which is really annoying, unless I sell them for like 5$ each they will likely stay with me

 

[fishguy1978]

My 6 Myleus Rupripinnis Redhooks (1M/5F) are in with 15 Metynnis, 2 H liberifer and 3 spotted Rafael cats. The tank is 260g (84in x30in x24in). They are still spastic but that’s silver dollars.

My Silver Dollar Sp's

I have 3 subs of SD I think. 1. M. Lippincotainus 2. M. Argentus 3. M. Hypsauchen I would like to add Metynnis Fasciatus once the 220g is up and running. Pictures in thread https://www.monsterfishkeepers.com/forums/threads/hardscape-additions-really-heavy-rocks.728284/page-4#post-8216946

www.monsterfishkeepers.com

 

[Ansorgii]

I figured out what the issue was.

It was the dark Sand in combination with the Cichla, for some reason it makes them extremely nervous and panicky, and that translated to the myleus. After I gave mine away to a friend with white Sand they were calm and confident in the instant they entered his tank.

I gave the myleus away but brought them back after the cichla were gone. Now they cruise threw the tank confidently, and aren't bothered by me or anything really at all. Its really a joy to have them. 2 Males always breed with each other after water changes, but since no female joins the action nothing apart from milky water comes from it.

To close this off, have some pictures of my favourite male of the group.

 

[FJB]

Beautiful fish!
I am very happy to learn you were able to get them back and that you figured out at least part of the reason for their skittishness.
I have never had my SDs with dark sand, so I don't really know if that would affect their behavior (2 groups in two different tanks, both with relatively light beige(ish) sand and plants).
Your fish look big, happy, displaying to each other, and in their prime. Very nice! I hope you were able to get the bigger thank you wanted.
From the last picture I see you also have some Metynnis SD's (not all are red hooks). Would you care to show some of them in another nice picture? or two?

 

[Ansorgii]

Thank you.

They went to a friend for a very cheap prize, but since he wanted to slim out his tank later on I got them back for the same.

They are no longer skittish at all. They were neither with him in a light sanded tank and not in my dark tank either, so I guess the colour does not affect them either way. But having a strong current seems to make them more comfortable.

The bigger tank is still in construction, I have to renovate a new room for it due to static concerns in the old, but I will post pics once it is finished, tho that will take a while since I am very busy atm.

I can try to make pictures of it tomorrow, I only have one of it, it was a bycatch in the import of the Torquatus. It's higher than long and I dont know the species, only ever saw some asian video of a group of them on youtube once.

 

[Ansorgii]

Here are some pics, if someone knows the species feel free to let me know

 

[FJB]

Nice specimen. That is Metynnis hypsauchen. It looks like a female. I would guess nobody bothers it (sexually) because the other dollars (Myloplus) are much larger and there are males and females among them. Just curiosity - In that tank, how many silver dollars you have in how many gallons of water?