# Possible sexing Spilo's???



## serrasalmus_collector (Mar 9, 2003)

About 6 months ago I an a partial success with breeding spilo's... Because of reasons I chose not to disclose my parent fish were immediately sold... There must be a god, and I must be destined to breed piranhas... I got them back yesterday. Apparently these are the same fish... And appear very dis-simular... Maybe I am seeing too much in to it...

Please shed some lite on these differences in fish...


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## EMJAY (Feb 27, 2003)

they definitly look different from eachother. but they could have just been born different.

are you comparing them to the ones you had before? and to eachother? im confused when you put the line "Apparently these are the same fish... And appear very dis-simular" then talk about the sex of the fish.

but either way, those are some crazy looking P's


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## serrasalmus_collector (Mar 9, 2003)

Those are exactly the ones that had spawned before.. I got my exact fish back... I was just looking closely @ them and taking some photo's... I noticed some big differences.... Odd... Maybe I'm just looking too deeply into it.. But I posted for possible sugestions...


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## kouma (Sep 1, 2003)

SC I have an observation as well, which I also noticed on mine. The female has a thicker (flater) end-before the actual tail starts; where the male has a thinner end (just before the tail starts) and a litte longer than the female.


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## serrasalmus_collector (Mar 9, 2003)

I am very glad to have these guys back.. Perhaps we may all learn something... I am growing water spites and Java moss for there breeding them again... If they do it again, the breeding will be photographed and filmed... If not they are truly beautiful fish... Glad they came back home to me


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## serrasalmus_collector (Mar 9, 2003)

kouma said:


> SC I have an observation as well, which I also noticed on mine. The female has a thicker (flater) end-before the actual tail starts; where the male has a thinner end (just before the tail starts) and a litte longer than the female.


 Thank you very much for the observation... I am patiently waiting for my fish to spawn again, so I can do microscopic sexing... Perhaps by sorting them a noticable difference may exist...Pehaps there is a subtle appearance differnace... But that could also come about from captive breeding and isolation... Damn... I get confused @ times


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## Xenon (Nov 15, 2002)

I am still sticking with Franks original postings that said piranha were sexually dimorphic. I would be interested to see this method applied to other fishes and the outcomes validated.


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## hastatus (Jan 16, 2003)

> Xenon Posted on Dec 8 2003, 01:54 PM
> I am still sticking with Franks original postings that said piranha were sexually dimorphic. I would be interested to see this method applied to other fishes and the outcomes validated.


"You can lead a horse to water.............."

What I observe in the above photos are damaged anal fin lobes (1-3 rays) that have regrown and quite obvious on 2 photos above. This "thick and thin" comments are as old as pirana books and long since discarded to detemine sexual dimorphism. Unfortunately, it continues to surface by people still thinking their limited number of fish is representative of an entire species.

Truth be told, the only known characteristic of sexual dimorphism in grown S. spilopleura is the full grown adult size (males smaller, females larger) and that is NOT carved in stone, particularly with tank raised fish which are genetically altered from the original stock. Or using microscopic exam of gonads which is 99% accurate. These are the same things I have repeatedly stated over and over again, not only to SC but other members as well. Yet, I find that photos still appear with the same tired old argument. With the exception of P. denticulata, Piranas are NOT sexually dimorphic.

Nice photos though.


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## serrasalmus_collector (Mar 9, 2003)

Thanks.. For the info. I just know for a fact this is a male and female fish... I just got them back and took some pictures... To my surprise I noticed dis-simularities... I would have never thought of damaged anal fin lobes... Great eye there guy!!!!

YOu are pretty smart... But I'm learning too...









Just kidding..


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## hastatus (Jan 16, 2003)

> serrasalmus_collector Posted on Dec 8 2003, 08:50 PM
> Thanks.. For the info. I just know for a fact this is a male and female fish... I just got them back and took some pictures... To my surprise I noticed dis-simularities... I would have never thought of damaged anal fin lobes... Great eye there guy!!!!
> 
> *YOu are pretty smart... But I'm learning too...
> ...


Kidding about you learning? I agree.


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## klinzou (Dec 12, 2003)

I was actually looking at sexing some the other day in the Tenn. Aquarium. I also noticed somethign about the heads being slightly diff shapes and the fin. I don't know that these were male/female pair, but the difference is noticeable. Maybe if everyone that breeds some can post pics, we can begin to see a pattern and get a definitive answer.


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