# Changes Due To Stress



## memento (Jun 3, 2009)

Now this is something I didn't expect...

I removed the divider between the two Serrasalmus species. Of one I was sure it's S.rhombeus, the other one remained a mystery to me.
Clear eye, hyaline end of the tail and no humeral spot.

Now it's well known that lack of colour can be caused by stress. So I didn't expect the opposite to happen :
the colours are getting stronger when cohabbed !

Look especially at the difference in tail marking :

Before cohabbing :








And now, cohabbed with another rhombeus :


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## lorteti hr (May 29, 2011)

yeah I see a diff but only in tail color..
is that sanchezi?


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## memento (Jun 3, 2009)

No, both rhombeus I think, although the spotting is still a little odd.


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## Ægir (Jan 21, 2006)

Interesting.... Any aggression or fin nipping?

Be sure to keep us updated as to what happens!


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## memento (Jun 3, 2009)

The lights are still on, so no serious chasings.
Probably tonight some fin nippings...


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## memento (Jun 3, 2009)

Day 2.

The small rhombeus shows a lot of fin nips.
The bigger one doesn't show any signs.
His tail marking hasn't changed, but the humeral spot has disappeared again.

Because I was working night shift and sleeping today, I'm not sure when this happened but I assume it happened in the night, when the lights are off.
Usually when the lights are on, they are less active.

Reduced the temperature to 25 degrees Celsius.

All nips are nicely into the fins themselves, none of them getting close to the body.
I do not consider them real signs of agression, but a result of setling the hierarchy.









The two together :










Next morning.

No further fin nips than when I left home yesterday.
Water is 24 degrees Celsius at the moment. 
Day 2, afternoon.

Some more finnips, dorsal and anal are almost completely gone now.
Still not a single bite into the flesh.

This certainly is a point where usually a cohab-experiment is terminated, but I still do not really think it's a sign of serious agression.

Reason for that, is the observed behavior of both.

They usually hang around pretty close to each other, or at least both at the same side of the tank.
When approaching, the bigger one turns around and most times, appraoches "full flank course". His snout touches the flank of the smaller one, than he turns away again.
The smaller one makes no attempt at all in these moments, to swim away.

On some occasions though, the bigger one makes the same turn but approaches to the caudal peduncle, with mouth slightly opened.
The smaller one doesn't swim away on these moments either, untill the bigger one turns some more and approaches from behind.

The smaller one swims away immediately, followed by a short chase which comes to an end as soon as the bigger one no longer can approach from behind.

The white spots in the water and on the snout are air bubbles. The filter outlet is just above it









Day 3

No further nips are found. 
The smaller one hangs in a left corner, the bigger one hangs around in the middle of the tank.


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## lorteti hr (May 29, 2011)

OMG man...
save the poor fish..
I understand,serra is not a shoaling fish..you don t have to do this annymore..
i don t know how can you watch something like that..
that little fish is never going to be normal..that is a huge stress..


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## memento (Jun 3, 2009)

Pygos ain't shoaling fish either...
And without any documented attempts, we would still consider them to be solitairy species.

Same for Serrasalmus - yes, most are solitairy species. But without documenting what happens when cohabbing them, we'll never learn how they interact.
Nor will one ever learn what it takes to keep them together, or even breed them.
How do you think, we came to learn species like geryi, maculatus and sanchezi can be kept in groups ?

How can I watch something like this ? Just from an objective point of view. I want to see how they interact, whether there's agression or just feeding on each others fins.
"Normal" and "huge stress" are two terms I leave out of it.
The fins will regenerate, so far I find it interesting that the nips don't go any further than the point of where it will regenerate completely.
And stress... well, that depends on how you look at things.
A fish in captivity has stress anyway. And in the wild, where they are pretty much on the bottom of the food chain, stress is a lot bigger.

And to put it in perspective - yes, it may result in a mortality.
But so do many groups of Pygo's. Why is it, we don't have a problem with Pygos being kept together, while in many cases one or more individuals get killed ?
Just because the stress is less visible ?


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## lorteti hr (May 29, 2011)

yeah but you said that these two are serrasalmus rhombeus..???
so what is the point of these example?
since the days of diapers we know that these species do not go together..


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## memento (Jun 3, 2009)

lorteti hr said:


> since the days of diapers we know that these species do not go together..


How do you know that ? How often have you tried ?
Or is the "it's impossible" just something that's been told for ages ?

Fact is, if two species don't go together, they don't breed.
If species don't breed, they would be extinct.

They're not extinct, so there must be a possibility to keep them together, or even spawn them.
Now of course the next remark is "it'll take a very large pool to spawn them" but that again, is just something that's been said forever. 
Just as it was about P.cariba, even though Jim Smith spawned them in a 180 litres tank.... considered wáy too small.

So from there I get to your other question - what is the point of it ?
I don't accept an "it's impossible just because we say so" reasoning, for it's a sophism...
It may work or not, but without any documented attempts it'll always be just a sophism.

About a year ago, a Belgian guy managed in breeding P.metallica, a species of tarantula that had never been bred in captivity before.
He tried for many years and finally found the exact circumstances needed, to get it done.
Two months later, a Dutch guy followed his "protocol" and had a succesful spawning as well.

The main difference between these two hobbies is, that in our hobby we tend to think things are impossible just because so far no one really maneged in it.
And instead of sharing and learning from each others failed attempts, we stopped sharing them.
"Trail and error" became impossible, because all those who actually tried got trashed and chased away from the forums, and from the hobby.

In the other hobby, people maintain the system of "trail and error" and because they share experiences, other people who want to try learn from these shared experiences.
Untill even an "impossible" spawning was accomplished, several times.

If this hobby would have maintained a little more open-minded attitude instead of thinking and believing in sophisms, Serrasalmus species would have been cohabbed succesfully and probably even spawned, for many years by now.


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## lorteti hr (May 29, 2011)

all I can see that this little fish is going to die soon..
I don t know what more do you need to say,ok that is not a good idea..
why don t you try with 5 or 10 of them..
maybe its the same way like with exodon paradoxus..maybe they need to be in the bigger shoal..


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## memento (Jun 3, 2009)

Ain't easy available over here, so I'm giving only 2 a shot.
Also easier to observe the interaction if you have only a few.

Day 3 Evening

Still no new nips and both hang around in opposite sides of the tank.
The bigger one shows no interest in the smaller one at all, only a few approaches followed by swimming away again.


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## lorteti hr (May 29, 2011)

yeah....dead by dawn...


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## memento (Jun 3, 2009)

Probably not. Most finnips seem to happen in daytime so far









But tell me... if it was to be that agressive, why is the smaller one still alive, and been left alone for 24 hours now ?


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## lorteti hr (May 29, 2011)

maybe it s to fast for the bigger one..








but without fins and tail I don t know how he can swim annymore..
try to put other fish in a tank(feeder fish)and see what is going to hapend..


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## memento (Jun 3, 2009)

Still enough of the caudal left to swim. But so far no need for it, he's left alone for now.


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## memento (Jun 3, 2009)

Allright, after 85 hours I took out the smaller one.
Still no new fin nippings or serious bite wounds, but because he's missing a big part of the caudal fins and both the dorsal and anal fin, he's having difficulty to remain his balance.
His entire posterior part of the body is flopping around to stay in position, what drew the attention of the bigger one.
No serious attacks, but some curious approaches.

On arrivsal of the bigger one, the smaller one plays dead. He just stops moving and lays on his side on the bottom.

Took him out and placed him in a 25 litres recovery tank.


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## Piranhaa (Jul 19, 2012)

May i ask: What's the reason, why you chose a bare tank? Woulden't it be more appropriate to try to copy their normal enviroment, where they are shown to swim around together?


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## memento (Jun 3, 2009)

Several reasons. 
First one, I like bare tanks... you only have the water, and the fish. And those are what I like.
"Copy their natural environment" is something I hear a lot, but how do you consider that even possible ? No matter what you do, it'll never even be clóse to their natural environment.
Decoration etc, only fit one purpose : to please the fishkeeper, not the fish.

A second, mayor reason, is that decoration and hiding spots become reasons for territorial disputes.
Others may say a submissive fish needs a place to hide, but to the dominant one that's a sign of weakness, triggering more agression once the fish comes out of it's shelter.


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## lorteti hr (May 29, 2011)

ok man cure that little guy and sell him to someone,he suffered for a long time..
you also see that this is not goin to work..you just waste a nice looking fish..
I m gonna give you 2 pirayas for that little guy..ok...


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## memento (Jun 3, 2009)

lorteti hr said:


> ok man cure that little guy and sell him to someone,he suffered for a long time..
> you also see that this is not goin to work..you just waste a nice looking fish..
> I m gonna give you 2 pirayas for that little guy..ok...


Says the man who has a cichlid in his piraya tank... you know one day that cichlid will be dead, don't you ?








Not sure about selling, just let it recover for now and see if I'll undertake another attempt with different circumstances, or not.

Don't spend your time trying to convince me things won't work after one failed attempt mate, I can assure you thát is something that won't work









One of the earliest tracks of a flying machine, dates back to ancient Greece. An unmanned model flew for about 200 metres. Now thát was something considered impossible, and I can imagine people telling him "you also see that this is not goin to work.."


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## lorteti hr (May 29, 2011)

I bet in a 100$ that this cichlid will live with them for a year..
will you take a bet or you are scared...???


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## memento (Jun 3, 2009)

I don't do online bettings








However I don't think it'll last a year... they have a different growth rate.


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## lorteti hr (May 29, 2011)

man you don t understand,this cichlid is on a training days(how to become vicious)
this is a special training for fish..
so when I put him back in my sister tank,he will be a MF BOSS..


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## Piranhaa (Jul 19, 2012)

I said TRY to copy. Atleast, everything else than a bare tank is closer to their natural enviroment. 
Stuff like blackwater, leaves and drifwood is what they swim next too in the amazon, not just emptyness. 
Tho i dont think it matters, wether you keep drifwood, or a plastic log in there.

I think you are completely wrong about it's only pleasing the fish keeper to decorate the tank. I have only seen positive results by giving (only Pygo's) hiding places. They seem too swim alot more in front of the aquarium, because they seem more relaxed, because they know that they are able to hide.

In my opinion, piranha's in a bare tank is blown in the head by stress, and are much more stressed than piranha's with opotunities to hide and explore in the tank. 
I dont think that a piranha in a bare tank, is able to show near anything close to their natural behavior.


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## memento (Jun 3, 2009)

Mine swim in front of the aquarium all the time, why won't they ?
Got nothing to do with hiding spots... if they're used to you, they don't get scared by you.

I disagree a empty tank is furthest from natural environment. Most of the amazon, is just a river - nothing more. Sand and water. With a visbility of almost nothing. Do you really think they see all the natural beauty surrounding them, in waters that often have a visibility of less than a meter ?

What they swim next to in the amazon, are other fish. Alligators. Dolphins. Anaconda.
So if you want to try imitating their natural environment, don't expect some leaves and Vallisneria to do the job... it ain't. It's not even clóse to being a copy.
As you said yourself - it doesn't matter whether you get real wood, or plastic stuff in there. The fish don't give a crap about it. It doesn't make them confident...

"Natural behavior" is something I don't see, but nor will you. Why ? Simply because they are nót in a natural environment.
In my experience, having hiding spots and plants doens't make them anymore natural. They still are fish in captivity.
With lack of exercise and lack of natural circumstances....

If you promote natural circumstances, does that mean you shut down filtration and food for a couple of months, to create a more natural dry season ?

Another thing - blackwater... do you use it, and why ?
is it natural for most species ?
Do you also drop the pH to lower figures, making it as acidic as blackwater is ?
Most species are found in clearwaters... not blackwater.

You mention you've seen only positive results with fish being allowed to hide.
I haven't. 
Most positive settings I've seen, are overstocks with seasonal simulations like stopping food supply for a couple of months. Mostly in bare tanks.

Most others I've seen being labelled as "healthy, happy piranhas" are overweighed, unhealthy animals...

It's just a matter of perception. I accept the fact that they'll never show natural behavior, nor do I expect them to do so.



Piranhaa said:


> I said TRY to copy. Atleast, everything else than a bare tank is closer to their natural enviroment.
> Stuff like blackwater, leaves and drifwood is what they swim next too in the amazon, not just emptyness.
> Tho i dont think it matters, wether you keep drifwood, or a plastic log in there.
> 
> ...


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## Piranhaa (Jul 19, 2012)

I do not agree this memento.

In the nature they swim around driftwood, fallen leaves and plants. 
They have places to hide in nature. This is why i think it's more natural for the fish.

From my point of view, Piranha's living in a bare tank, is fucked up in the brain by stress, not saying that Piranha's not stressed in the aquarium, but from my experience, they are more calm when decoration is around.

My pygo's for example, got more and more calm, and was swimming much more around the tank when they knew they had a place to hide if they needed. I dont think it matter, wether fish needs driftwood or a plastic log to hide behind, but i think they do relax more, when they know there is something in the tank to envistigate, and to hide behind.


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## memento (Jun 3, 2009)

Let's agree we disagree


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## Piranhaa (Jul 19, 2012)

Ye, let's do that


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## lorteti hr (May 29, 2011)




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## memento (Jun 3, 2009)

lorteti hr said:


>


Not my way.... 
I prefer concluding we have different opinions, are entitled to them and just grab a beer...


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## lorteti hr (May 29, 2011)

so update....how is the little guy..?


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## memento (Jun 3, 2009)

Doing fine, have no lightning on that tank so hard to take a pic...
Just a matter of time to let the fins regenerate


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## lorteti hr (May 29, 2011)

great to hear that man..
can t wait spring so I can try cohab serra compressus..
the biggest challange would be serra elongatus(do you agree?)


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## memento (Jun 3, 2009)

No, I think rhoms are the biggest challenge because of the cryptic species.
When cohabbing them, you'll never know if it's only one species you try, or several species...


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## canadianforever (Nov 2, 2012)

keep us updated id love to have a shoal of rhoms or elongs


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## lorteti hr (May 29, 2011)

canadianforever said:


> keep us updated id love to have a shoal of rhoms or elongs


sure I will mate..


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## lorteti hr (May 29, 2011)

so update dude....


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## memento (Jun 3, 2009)

Not much to update... still have 'm seperated.
Anal and dorsal fin are regrowing rapidly, caudal one is regrowing a little slower.


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## lorteti hr (May 29, 2011)

memento you should take a bet..


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## memento (Jun 3, 2009)

Too bad for you, just spend my christmas bonus on sponsoring manta ray research... no money left for betting


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## memento (Jun 3, 2009)

Final update : sold both the rhoms


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## lorteti hr (May 29, 2011)

memento said:


> Final update : sold both the rhoms


nice of you mate..


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## memento (Jun 3, 2009)

Just reducing the hobby, that's all


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