# Let's crack the Sex Code



## PiranhaStein (Dec 30, 2005)

For how much time and how much knowledge we have on piranha's we should be able to have a system to figure if they are male or female. I have a problem solving style mind and I know people are going to say it's just impossible, but there has to be some general characteristics that will help us find out what we have in our tank.

Here are a list of things that we might consider some defining characteristics of the sex of a red belly.

Length
Width
Temperment
Hunger
Coloration
Swimming Style
Territorial choices
Favorite foods
Jaw size
Any Fin Size

Length divided by the width(maybe wider or more boxy to incorporate the eggs)

Just throwing some things out there, For how much knowledge and time that is spent on p's we should be able to crack this code.

Any one with a breeding pair please list any differences between the male and female that you have noticed, i'm sorry to say that i'm not at that stage yet but I would like to know if I need any particular fish. What is more dominant males or females in terms of population in tanks?


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## hastatus (Jan 16, 2003)

Have fun.


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## Slim (Jan 9, 2005)

Id be more than happy to go over some things ive noticed about different sexes in the Redbellies, but thats all I know. And it may not even be correct but ive noticed differences in my males and females drastically.


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## PiranhaStein (Dec 30, 2005)

This is going to be a psudo science to start out with, but if we can find a couple of commonalities between breeders I think we can do better then "you can't tell we don't know"

Let's start a Male and Female Characteristic Lists.


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## spoondc2 (Oct 29, 2005)

male rbps has red markings on their belly , female rbps has red markings on their belly too , hmmn which 1 is male or female ??? u can tell by looking at their face if its mean ugly looking black face its a male ..if its not as mean looking but still has that ugly black face its a female .. Dr jekyll told me this info before he went to hide :]


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## PiranhaStein (Dec 30, 2005)

thanks for the bump


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## HellSpawn (Oct 7, 2004)

yeah that would be cool, id like to find out for myself which of my fish are male and female, good luck man


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## Ægir (Jan 21, 2006)

from what i have seen, you may be able to pick out SMALL differences, when they are at full maturity and are about to die of old age... good luck!


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## Slim (Jan 9, 2005)

Skunkbudfour20 said:


> from what i have seen, you may be able to pick out SMALL differences, when they are at full maturity and are about to die of old age... good luck!


Ya small differences there are no big differences at all.


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## PiranhaStein (Dec 30, 2005)

small differences are something that can be worked with. Again i'm not looking for a proven method of being able to select what sex it is. I'm just looking for some info from anyone who has a breeding pair and see what commonalities a specific sex has, 10 or more breeding pairs. If we could predict sex by 70% or have something to go off of then we might have something better then a coin flip. There are so many breeders on this forum I'm sure that a good amount of info can be collected here and some conclusions or ideas can be formed from them.


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## TheTyeMan (Aug 9, 2004)

as far as I know their dna has nothing in it as far as exterior physical differences go. the only time I notice a difference is when mine are about to lay eggs.


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## 33truballa33 (Oct 18, 2004)

do a search.. not trying to shoot u down but this has been brought up time and time again. best advice is look for a bulge in the gut at fully matured sizes.. but other than that and rounded shape which applies sometime ur without a paddle..

so as he said



hastatus said:


> Have fun.


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## Fry (Oct 9, 2005)

I think we should get some pictures with 100% positive i.d's posted here with male and female specimins.


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## PiranhaStein (Dec 30, 2005)

lil fishy said:


> I think we should get some pictures with 100% positive i.d's posted here with male and female specimins.


That's a really good idea. I think there are going to be some similarities to be found or commonalities for one sex.


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## Slim (Jan 9, 2005)

My females are all larger than my males, just plain out bigger all around, and their bellies are bigger also. Another thing I have noticed is in my tank the female never sticks around to guard the nest the male does, but you have to remember thats my tank I know some people whos are very different. My largest male has more of a blunt front to him also looks alot meaner than all the others.

male and female pics. The pic with the pleco in it is my main female who has passed away. and the other is my main male who is suffereing from some type of disease now. My whole tank is going to crap.


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## Elongatus cockus (May 28, 2005)

I think our best bet would be to focus on behavioral differences more than physical differences.

Slim said that females are less likely to guard the ness. How does this translate into her prebirth behavior? Was she more dominant when it came to attacking food, etc...


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## Fishjunky (Nov 11, 2005)

Elongatus cockus said:


> I think our best bet would be to focus on behavioral differences more than physical differences.
> 
> Slim said that females are less likely to guard the ness. How does this translate into her prebirth behavior? Was she more dominant when it came to attacking food, etc...


Wow! I can't tell you how much this thread is helping me. 4 weeks ago I got 3 Reds from a friend of the family. He has had reds spawning forever. He was getting rid of them becuase his wife wants "peaceful fish". Hey I'm not one to critisize. Espeacially when three 7" Reds are in it for me! One of the three really looked bad to begin with and simply did not make the trip. So I was left wondering if I had the pair or not. The Pics you posted here look identical to my fish! So now I'm stoked!









I'm a water change nazi 1/4 of the tank twice a week with R.O.D.I. With these fish I've been keeping them blimpped to the point they look like they are going to burst! I lower a chicken drumstick, schrimp or smelt into the tank 4 times a day and let them get their fill. I also keep feeders in the tank constantly. The one that I'm suspecting is a male seems to have begin staying in one particular area in what I call the drift wood forest!LOL! and seems to have backed off of the food in the last two days.







I will keep you all posted. man I really wish I had a camera.


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## Slim (Jan 9, 2005)

Fishjunky said:


> I think our best bet would be to focus on behavioral differences more than physical differences.
> 
> Slim said that females are less likely to guard the ness. How does this translate into her prebirth behavior? Was she more dominant when it came to attacking food, etc...


In the start to finish of the amazon love making the P's do when breeding, my male had to be on one side at all time the female would move and the male would switch right back to the other side. Like he wanted to be on top or something. I fed them the same throught the whole course of breeding until now. Always have. i had 7 in the tank and i know 3 were females and 2 males. The other 2 didnt get to grow out so know telling for me. Im pretty sure I only have 2 females left And i know one of them is one of my breeders. The dominant female breeder ( Big Momma) Ate more than any of them. She really didnt fight for the food just got there before the rest of them. I also feed my P's strictly shrimp and thats all.


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## xtreme_s10 (Mar 14, 2005)

Male
View attachment 96155


Female
View attachment 96156


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## Zip (Apr 17, 2005)

Slim said:


> My females are all larger than my males, just plain out bigger all around, and their bellies are bigger also. Another thing I have noticed is in my tank the female never sticks around to guard the nest the male does


I have the same situation. My male is definitely smaller/thinner than the female (and they are from the same brood). The size difference is becoming even greater because the male's appetite has dropped quite a bit since the first time they started breeding (they've bred about 20 times since starting around 8 months ago), so she's outgrowing him (and so is the 3rd P I have, which I also suspect is a female from the appearance, but she's never hooked up with the male.)

He eats almost nothing when spawning or guarding the nest. Even when he isn't actively spawning or guarding he doesn't eat nearly as much as he used to. I'm inclined to think it's because I feed them in the area where they usually build their nest (since it's the only clear area in my planted tank), and he doesn't feel comfortable eating around it, but that's just my theory. It's been about 6 weeks since their last spawn now, but he's still a light eater.


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## PiranhaStein (Dec 30, 2005)

If your trying to induce breeding I would try the low water trick after a heavy feeding.

Great posts everyone We have a couple of leads to go on now and we can only do better from here. Congrats on your pickup hopefully the two new additions will produce some good fry. ANd slim I would recommend removing everything from the tank and washing it off, raisin the temp and adding a bunch of salt. I know you've been here longer but there has to be something that you can do to stop this disease from taking over.

Thanks for all your posts, I'm looking forward to adding some of my own insight once I get my p's in breeding form.

And I would vary the diet of only shrimp a little bit, some bio gold would be a nice addition.


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## Slim (Jan 9, 2005)

PiranhaStein said:


> If your trying to induce breeding I would try the low water trick after a heavy feeding.
> 
> Great posts everyone We have a couple of leads to go on now and we can only do better from here. Congrats on your pickup hopefully the two new additions will produce some good fry. ANd slim I would recommend removing everything from the tank and washing it off, raisin the temp and adding a bunch of salt. I know you've been here longer but there has to be something that you can do to stop this disease from taking over.
> 
> ...


Ya im getting rid of my reds on friday whoch would be tommorow. Tank broke on me so just getting rid of them and keeping the spilo in the 75 gallon


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## PiranhaStein (Dec 30, 2005)

sorry to hear that man, hope they get to a nice home.


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## Slim (Jan 9, 2005)

PiranhaStein said:


> sorry to hear that man, hope they get to a nice home.


They are. A friend bought my tank and my fish so he is going to fix my tank and set it back up.


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## tnpeter (Dec 17, 2005)

is it me or do the male nose nosstels things looks closer to the eyes then the females? i looked at this many times, any one wanna do some reseah on this


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## moeplz (Feb 21, 2005)

hastatus said:


> Have fun.


When you hear that, it means give up.


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## PiranhaStein (Dec 30, 2005)

tnpeter said:


> is it me or do the male nose nosstels things looks closer to the eyes then the females? i looked at this many times, any one wanna do some reseah on this


It does to me, when the answer comes to the identify thread then we can work with those pics too and break them down.


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