# Piranha Maturity



## Sir Nathan XXI (Jan 29, 2003)

I slightly disagree with Franks post on piranha maturity, however I may be wrong. I believe most Pygocentrus species come into maturity sooner than Serrasalmus species because Pygos life span is much shorter than that of Serrasalmus. Proof of this matter would be the average growth rate of each type. I had a piranha (which died on christmas morning unfortunately) that was a female Nattereri. She was about 8.5" and was about 1.5 years old at her death. She had began to carry eggs at just over a year old. She never actually bred because my male took alot longer to mature than she did. One time they were preparing to spawn but I had to move them to another house so that ruined that whoel process. But my point is that Nattereri can come into maturity around one year of age. This may not be the case with all Natts or all pygos but it could vary well be the case. I know Machete of Pfish had Natts breed at just a little over one year in age. The reason I know is that when my female began getting eggs I couldnt believe it, but he confirmed that indeed it is possible. It is highly possible that some Serrasalmus come into maturity at 2 years but my opinion is that it takes most of them about 4 years or so, afterall some Serrasalmus are only around 4"-5" at 4yrs of age, hardly big enough to carry many eggs if any.


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## MPower (Jan 29, 2003)

You have a good point and I would have to agree with you.


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## hastatus (Jan 16, 2003)

Hello Nate, since you've chosen to disagree with me in public, which is your choice, I will examine your argument in hopes you might be a bit more enlightened in how to present a much better viewpoint. I trust with all your experience in piranhas and having visited your web site [at your invitation] we can have a good open discussion here.

[I believe most Pygocentrus species come into maturity sooner than Serrasalmus species because Pygos life span is much shorter than that of Serrasalmus.]

You may believe whatever you wish, however what is required here is _proof_ and your statement that [Pygos life span is much shorter than that of Serrasalmus] is erroneous. I invite you to read my article which is well documented on the life span of _S. rhombeus_ in captivity, a fish which was alive for about 30 years, perhaps longer, but died through an accident at the Steinhardt Aquarium. The species _P. nattereri_ is also well documented to live past 30 years in captivity, a hobbyist E. montgomery has kept her piranha alive for a bit over 32 years. I have some local people in Roseburg, Oregon who kept a well documented _P. nattereri_ for 35 years until it died a couple of years ago.

The rest of your post which is full of unconfirmed and unsubstantiated information would be best served if you could produce actual growth stats and dates instead of leaving such open statements left for interpretation.

There are yet to be any scientific reports on the exact onset of sexual maturity in piranhas, so regardless of when you think they are active, it has not be proven by science or field research. The closest done has been by Lamas, Ivana Reis, and Godinho, Alexandra Lima, 1996 Reproduction in the Piranha _S. spilopleura_, you might get yourself a copy of it and read it. It will enlighten you more than opting for opinions without merit. The rest about your dying piranhas is difficult to fathom how you came up with those ideas _as fact_ since egg implosion is fairly common with females.

If you wish to continue this discussion please present a bit more evidence other than opinions or hearsay.

Again, good hearing from you.


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## Sir Nathan XXI (Jan 29, 2003)

When I speak of age reached I mean in the wild, not captivity. Pygos live a much different life than Serras do. Feeding in packs Pygos experience more injuries and possible infections which lead to sooner deaths than the Serras do. Think of it this way, why would pygos grow soo fast to live just as long as a slow growing Serra? My other point is that Nattereri do become sexually mature at about 13 months of age or at least females do. I know for a fact my female that died was only 16 or 17 months of age, I dissected her to try and determine a possible cause of death, her eggs sack had ruptured and eggs filled her entire inner body cavity.

Very little facts are actually know about piranhas as compared to most fish, Frank you should agree with me on this one. Therefore as hobbyist we dont have many facts to fall back on for reference. The most we can do is critically analyze our fish and their behavior and make the most logical conclussions as we can from them. That is how possible studies are started. I am not trying to say that I am 100% right or anything, I am just trying to shed light on possiblities and facts that I have witnessed. All my intentions are, is to help progress the knowledge of piranhas, as I have said before I do come up with some wild ideas now and then, but generally my hypothesises are generally agreed with by many experts in the field

Who ever said I wasn't or anybody for that matter is not allowed to dissagree, I respect you Frank, but I dont know what you meant by your first sentence


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## hastatus (Jan 16, 2003)

[When I speak of age reached I mean in the wild, not captivity. Pygos live a much different life than Serras do.]

You still do not offer any research date or references to back up your claim for field studies. And piranhas do grow old in all the genera so long as they are not eaten or fall prey to disease. Again, you are mistaken regarding the phylogeny of piranhas and their ecological niche. I think you need to do some very serious readings before you enter a discussion of this magnitude or you will look very silly. --- that is not to offend you but a keen observation of what your level of experience is.

[Feeding in packs Pygos experience more injuries and possible infections which lead to sooner deaths than the Serras do.]

Again, you are making a broad, generalized statement about two species without proof or merit and no field studies to back up your claim.

[My other point is that Nattereri do become sexually mature at about 13 months of age or at least females do. I know for a fact my female that died was only 16 or 17 months of age, I dissected her to try and determine a possible cause of death, her eggs sack had ruptured and eggs filled her entire inner body cavity.]

Again you have verified what I said in my remarks to you, eggs implode in females often causing their demise. The age is set at approximately 2 years by scientists who have researched the data and are published in scientific journals. You can find appropriate references at my web site.

[Very little facts are actually know about piranhas as compared to most fish, Frank you should agree with me on this one. Therefore as hobbyist we dont have many facts to fall back on for reference.]

You have facts, but some of you choose to ignore them when science presents them to you. This is atypical mental block from digesting to much nonsense from people that use opinion to force an issue.

[The most we can do is critically analyze our fish and their behavior and make the most logical conclussions as we can from them. That is how possible studies are started].

Again if you are comparing this to field studies you are wrong. Little to none home studies of piranhas are recognized by science because your home aquarium is not a lab nor is it representative of a natural condition in the Amazon. If you wish to share this at the hobbyist level then you are posting in the wrong forum.

[All my intentions are, is to help progress the knowledge of piranhas, as I have said before I do come up with some wild ideas now and then, but generally my hypothesises are generally agreed with by many experts in the field.]

Actually if you came up with a statement like this to any biologist in the study of piranhas, you would be laughed out of the building. I do not say that to be mean to you, but you are really stretching it when you think your aquarium gives you knowledge on how fish interact or feed in the wild. It only gives you a small tiny margin of what actually takes place. And you are right in only one observation, piranhas have been ignored in studies, but many studies are now being conducted since 1986. Much of what you obviously are not aware of.

[but I dont know what you meant by your first sentence]

My statement is how I wrote it. If you disagree then you must be prepared to back up what you write. Very simple logic. Or you can do it via PM which can also be used for discussion where no one appears foolish.

Now to address the rest of your reply:

You have a web site that is full of material that any unsuspecting hobbyist would think is research material. There are no references, no credits and little data to support an actual study of piranhas, other than personal opinion or heresay. To an uninitiated hobbyist they would think the material at your web site is scientifically accurate. You say there are 4 species in Pygocentrus and then list them. I see nowhere on your web site that you are published in scientific journals or have the authority to say there are 4 species in Pygocentrus, when science has shown there is only 3 in that genus. Do you see what I mean? You are offering an opinion on what you think is an actual species, when you have nothing to show or prove your classifications are accurate. The same goes for much of what you have at your site. This is a common problem with hobbyists that want to help others learn about piranhas, but instead are repeating the same mistakes found in old piranha books. By the way, I am glad you have modified your post about the 17 inch so-called ternetzi, P. nattereri. I tried to tell you and others this fish is not a distinctive species from P. nattereri. I hope in time you will come to fully realize that just because it looks different doesn't make it different.

Lastly, since you are posting in the science forum, one would think you could substantiate your claims by better data and facts, since you are not asking a question but attempting to assert what you think is fact.

I hope this does not upset you or anger you. I am glad you respect me, but know this, I am here to educate the public and those that want to learn about piranhas beyond uneducated opinion, piranha books with outdated material, and speculations based on home aquariums experiences with no data to support it. If you are entering field study talk then you must be ready to support your arguments as well.

Best fishes,


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## Sir Nathan XXI (Jan 29, 2003)

OH, my mistake, I never even noticed this was the science forum. Our two websites differ in intentions. You have a site that is more based on the history and classifications of piranhas. My site is aimed more at how to take care of the fish better, and what their habits are and general info on the fish. I never intended it to be like a scientific journal or something like that. I am aim for a average Joe type of audience, most people wouldnt read a science paper


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## hastatus (Jan 16, 2003)

> You have facts, but some of you choose to ignore them when science presents them to you. This is atypical mental block from digesting to much nonsense from people that use opinion to force an issue.


Enough said. As I stated in my prevous writings and to others, take the time to visit the OPEFE web site, read what is there. I promise you I can talk to you in non-scientific terms so that you can understand the science papers if it is beyond your grasp. That is why a mind is a valuable thing to waste.


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## Sir Nathan XXI (Jan 29, 2003)

I understand science papers, that is all fine, I am just stating that wasnt my intentions when I made my web site. I have read your site in the past as well


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## fishman2 (Nov 27, 2002)

"I understand science papers, that is all fine, I am just stating that wasnt my intentions when I made my web site."

Well I understand science papers too, at least I can read some of it, but don't mean I comprehend it all, that's why we have Frank to explain it.










" I never even noticed this was the science forum"

Pays to read lol







just funning with you guy. I see you are a mechanical engineer. Are you taking an ichy course too? reason why I'm asking you seem to be into fish and have some knowledge.


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## Sir Nathan XXI (Jan 29, 2003)

almost everything I really enjoy, I always try to know as much and learn as much as possible, I raced MX for about 5yrs or so, and in that time I have learned enough to build an entire bike from a box of parts, I also learned how to mod the motors pretty darn good. Fish are no different to me, I love to learn about these awesome creatures


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## fishman2 (Nov 27, 2002)

"I raced MX for about 5yrs or so, and in that time I have learned enough to build an entire bike from a box of parts"

It took you 5 years to learn how to build a bike from a box of parts?

Is it that tough to do?







I really don't know, just wondering why it took that long.

" Fish are no different to me" You can build a fish from parts to? :







: :laughlong: 
"I never intended it to be like a scientific journal or something like that"

Sir Nathan from following all your threads, maybe its just how you write stuff, I don't know, but it sure does look like you are stating facts when you don't have anything to back your information with. From the git go on your webpage I see what Frank is talking about on how you are presenting yourself. Can I just say you do have good info on your site, but it does look like something out of Pita on what your piranhas think. Just my opinion anyway. :







:


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## Sir Nathan XXI (Jan 29, 2003)

I mean build a complete motorcycle from a box of parts









I took several Psychology classes in college, I know a bit about behavior and what it means and so forth

Franks site and mine are both on Piranhas but other than that they arent alike at all, my focus is more based on their care (that way we dont have any more dumped in rivers and lakes, so we can keep them legal) while his is based on the history, classification and lab tests.

We had two different things we set out to acomplish, and I think we both did what we wanted to do.

as far as stating facts, I am fairly lazy, I dont like to be long winded, yeah I know a bit, just dont care to type it all out. Like I say though, I am more concerned with their care, than the biological part


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## fishman2 (Nov 27, 2002)

"I am more concerned with their care, than the biological part" aint that supposed to be the same? I mean you are telling people there are 4 species in pygo's. Are you changing your mind on that?







You have alot of science stuff on your site. Just wondering where all this fits together ???


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## Sir Nathan XXI (Jan 29, 2003)

you must know the basics of their science in order to properly care for them 

as far as the 4th pygo, I sit on top of the wall, impartial to both, either way if it is or is not a 4th, whether its name is Ternetzi or not, I agree its name isnt Ternetzi, I still want to provide people with info on this particular fish whatever it may be from now on let it be know as Argentina Pygo


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## fishman2 (Nov 27, 2002)

"you must know the basics of their science in order to properly care for them"

Excuse but you stated earlier to Frank that your web site is not about science but piranha care. Now your saying you must know the basics of their science. Well if you can't prove your science, then it aint science, its an opinion! :







:


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## Sir Nathan XXI (Jan 29, 2003)

what needs to be proved, and quit screwing up my threads, stay on topic or stay off


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## fishman2 (Nov 27, 2002)

what needs to be proved, and quit screwing up my threads, stay on topic or stay off ""I never intended it to be like a scientific journal or something like that. I am aim for a average Joe type of audience, most people wouldnt read a science paper"

Sir Nate do you happen to see who is MOD here?

My remark still stands, you are offering only opinions. "you must know the basics of their science in order to properly care for them" Excuse but you stated earlier to Frank that your web site is not about science but piranha care. Now your saying you must know the basics of their science. Well if you can't prove your science, then it aint science, its an opinion!


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## Xenon (Nov 15, 2002)

Fishman2, you are completely out of line. You might have moderator written under your name but you are no better than any member here. I have administrator under my name but it doesnt give me the right to pick on someone...

This thread has been ruined and is franky nauseating to read....Nathan started this thread with good intentions...

:veryangry:


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## fishman2 (Nov 27, 2002)

Then make HIM the moderator....good luck dude~


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## Xenon (Nov 15, 2002)

This can be handled over PM and I would prefer it to be.


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## machete (Feb 6, 2003)

Sir Nathan XXI said:


> I know Machete of Pfish had Natts breed at just a little over one year in age. The reason I know is that when my female began getting eggs I couldnt believe it, but he confirmed that indeed it is possible. It is highly possible that some Serrasalmus come into maturity at 2 years but my opinion is that it takes most of them about 4 years or so, afterall some Serrasalmus are only around 4"-5" at 4yrs of age, hardly big enough to carry many eggs if any.


This is my first post here. Nice site guys. I do not want any trouble Nate. Someone told me about this thread, and there is some false information. Either you asked me and I was confused about the question, or you took my answer wrong. The nattereri I had breed were a year in my keep. Not a year old. I have no idea how old they were, to top it off they were wild caught.

I also have had tank bred natteri breed at around the two year mark. Maybe a little younger, I was under the assumption that it was more of asize factor than age though. But this is nowhere near a scientific statement, just ignorant staement. I will leave the science to the geeks and nerds


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## Sir Nathan XXI (Jan 29, 2003)

machete said:


> Sir Nathan XXI said:
> 
> 
> > I know Machete of Pfish had Natts breed at just a little over one year in age. The reason I know is that when my female began getting eggs I couldnt believe it, but he confirmed that indeed it is possible. It is highly possible that some Serrasalmus come into maturity at 2 years but my opinion is that it takes most of them about 4 years or so, afterall some Serrasalmus are only around 4"-5" at 4yrs of age, hardly big enough to carry many eggs if any.
> ...


hmmm, we must have not understood eachother somewhere....... I did have a female Natt though like I have said before that was about 13 months or so that started getting eggs so that made her a little over 1 year old


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## fishman2 (Nov 27, 2002)

Closing thread, nothing new about anything here.


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