# Marginatus / Compressus Differences



## Hogdog (Feb 1, 2010)

A few months ago I bought a Marginatus and as he's developed he's started to look alot like some of the Compressus' that I've seen. The only really distinguishing feature between the him and Compressus is the dark band at the base of the tail rather than at the tip.

Sorry but I don't have any way of getting photos up at the moment, not that it's about my fish particularly as I'm still fairly sure he's a Marginatus. I'll get some pics up as soon as I can get someone to do it for me.

Is it possible that the two are regional variants of the same species or is there more to it?

Thanks in advance.

*EDIT* There seems to be alot of variation in colour in both species which makes identification hard.

My Marginatus actually looks alot like the fish pictured on the bottom right of ths article,

http://www.piranha-info.com/default.php?lang=en&id=s_compressus


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## CLUSTER ONE (Aug 2, 2006)

i suggest reading the articles of the two species on opefe as it will explain it much beter then I could.


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## memento (Jun 3, 2009)

S.marginatus is part of the compressugroup, so looks a lot like the other members of this group.
It is howver a distinct species and the dark caudal "V" instead of the dark tailband is exactly the most distinguishing character


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## Hogdog (Feb 1, 2010)

CLUSTER ONE said:


> i suggest reading the articles of the two species on opefe as it will explain it much beter then I could.


I've had a look at both discriptions and to be honest there are no big distinctions between the two. I think this quote is rather telling,

"Géry (1977) placed S. marginatus as a subspecies of S. rhombeus (= S. rhombeus marginatus)....

The identification of the species is difficult and their classification is controversial. Seven or so forms may be recognized; certain of them, such as S. marginatus and perhaps S. medinai (not seen by the author), are very close to S. rhombeus and probably only subspecies of this common species. All have 13-16 branched dorsal rays and 28-36 branched anal rays."


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## memento (Jun 3, 2009)

Hogdog said:


> I've had a look at both discriptions and to be honest there are no big distinctions between the two. I think this quote is rather telling,
> 
> "Géry (1977) placed S. marginatus as a subspecies of S. rhombeus (= S. rhombeus marginatus)....
> 
> The identification of the species is difficult and their classification is controversial. Seven or so forms may be recognized; certain of them, such as S. marginatus and perhaps S. medinai (not seen by the author), are very close to S. rhombeus and probably only subspecies of this common species. All have 13-16 branched dorsal rays and 28-36 branched anal rays."


I don't think that rather sais it. It's a very outdated description by Géry... look at the more recent ones instead of the old ones.


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## Hogdog (Feb 1, 2010)

Any idea where I can find more recent info? That info was off of opefe.


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## memento (Jun 3, 2009)

I know. And right below it were more recent descriptions. You just quoted an old description by Géry, that was placed to indicate the discussions that have been kept regarding this species.
Right below that line was a modern description, with the earlier ones taken in account









It started with : "_The description below is based on current scientific literature and revisions. __S. marginatus is considered distinctive and not a subspecies of __S. rhombeus. Considered valid as __S. marginatus (Gómez, S. E. and J. C. Chebez, 1996).__The body pattern spotting is composed of small spots and ovals unlike __S. altuvei which has spots and elongated bars. Caudal fin forms a dark "*V*", terminal band is hyaline to dusky with adult. This fish may be a member of the "compressus-group" and is quite close in appearance to these group members._"


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## Hogdog (Feb 1, 2010)

Thanks CombiChrist.


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