# S. Compressus



## Piranhaa (Jul 19, 2012)

Getting a S. Compressus this friday, can't wait.

Here's a picture of the tank it's going to live in;

My link
This picture is a month old.

Just added plenty of new plants and 3 new new pieces of wood. It think it looks amazing now.

The Compressus is going to live their by it's own, and with plenty of Red Cherry Shrimps crawling around the tank as snacks.

I will update this thread with new pics when the fish arives.


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## Ægir (Jan 21, 2006)

Keep us updated on the progress! Cant wait to see pics of the new fish.


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## Piranhaa (Jul 19, 2012)

I will keep you updated, i promise! I can't wait either









Here is a pic i took today of the tank, this is how it looks now; 
My link

Unfortunately, my camera is not able to catch the murky effect that's in the water, it makes the pictures very strong in the colors. 
It's more brownish water irl, and looks cooler (my opinion), but im pretty happy with my results so far!


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## Piranhaa (Jul 19, 2012)

The S. Compressus is now in my aquarium, and it's looking very nice. 
It's pretty shy, and is staying behind some driftwood, but i guess it's pretty normal the first month or so.

Im not sure about ID, so if anyone can ID from these pics, feel free to comment.

My link

My link


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## memento (Jun 3, 2009)

Nice fish. As mentioned in your other topic, I don't think it's compressus.
First impression is gibbus, but that depends on the size of the fish..


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## Ja'eh (Jan 8, 2007)

memento said:


> Nice fish. As mentioned in your other topic, I don't think it's compressus.
> First impression is gibbus, but that depends on the size of the fish..


How will knowing the size determine whether it's a gibbus or not?


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## memento (Jun 3, 2009)

Ja said:


> How will knowing the size determine whether it's a gibbus or not?


It won't, but a 9-10cm fish isn't fullgrown yet.
So the ratio between body height and SL will still be changing in time, so the elongation can diminish during growth.
If this fish was fullgrown and had this ratio of elongation, it would fit S.gibbus.

A problem species though, for in some descriptions the elongation ratio described, is even bigger than in S.elongatus...


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## Ja'eh (Jan 8, 2007)

S. gibbus being more elongated than s. elongatus?







At first glance you don't see it.


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## memento (Jun 3, 2009)

Read the original description and the Jégu revision Ja'eh.
You base your opinion on the specimen you've seen identified as gibbus.

I've never seen *óne* of them, that actually fitted the descriptions. Hence my remark that they are just another problem in the rhombeus group.

In the Jégu revision, a elongation is described that is bigger than in elongatus.... and matches the one from pingke.
From a holotype that was believed to be lost.

What we've seen in the hobby being called gibbus, are rhoms. None of them matched the original description and revision.
That's why you hardly note the elongation - you're looking at rhoms.


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## memento (Jun 3, 2009)

For your own comparison :

S.gibbus
Height body : 37.8 (41.7-52.6)(44.4-48.8) - description by Jégu

S.pingke
Height of body: 41.5 (37.9) - description by Yepez

S.rhombeus Rio Maroni
Height body: 49.5 (46.4-53.5) - description by Merckx

Note that the maximum height in gibbus, overlaps the Maroni rhoms.
The ones I've seen identified in the hobby, are always in this maximum height part. None of them matches the lower ones, or even the average.
They all still match S.rhombeus.

You hardly don't see any elongation, cause you're looking at rhoms with a body height just below 50.
S.gibbus however as an average of 37.8 - aqn elongation you shóuld see clearly.


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## memento (Jun 3, 2009)

Now there ís of course the possibility, that the S.gibbus holotype indeed is lost, as it was believed to be.
In that case, the million dollar question becomes, what Jégu was looking at in his revision of the species.

If that was nót S.gibbus, the revision becomes invalid. And the geographical location "only Tocantins", is derived from that revision.
So in that case, locality should be Rio Araguay, as Castelnau described it.
So all identified as gibbus based on locality, become doubtful as well.

Even Jégu himself seems to have doubts by now about this species.


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## Ja'eh (Jan 8, 2007)

What about this fish? More elongated than average rhoms, orange coloring on the gill plate and breast area and distinctive red eye. Also the anterior end is not as concaved as s. rhombeus.


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## memento (Jun 3, 2009)

The difficulty is in your formulation itself : it's a comparison to an _average_ rhombeus.
The elongation is obvious, so I really understand why one would ID this as gibbus (if locality matches).

However a quick measurement (about to leave for work, so didn't have time for an accurate one), shows height / SL = 50%.

That is the very upper range for gibbus, but an average range for some rhombeus-populations like the Maroni population as measured by Jégu.

So yes, it's more elongated than the average rhoms we see, but it still matches the descriptions of rhombeus. While it only matches the very upper range of ratio seen in gibbus.
If you were to calculate with average ratios and it's standard deviations of both species, the calculation would show this is most likely rhombeus...


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## Piranhaa (Jul 19, 2012)

It haven't been eating yet, and i am starting to get worried.

It's been 8 days since i got it now.


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## memento (Jun 3, 2009)

Don't worry, normal behavior for a Serrasalmus.
They just need some time to get settled in a new environment, but won't starve themselves.

The rhom I've kept took about three weeks before he started eating.

Just throw in some feeders, the easiest way to see when he starts eating eventually


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## Piranhaa (Jul 19, 2012)

He's doing fine, and he is eating for good now









He is hiding all day tho. But i guess ill just give him some time.


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