The biggest RTC raised in captivity is 160 cm or 5'4", 41 years old (in 2013)

Backfromthedead

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Proven in millions of tanks around the world, with numerous species, is sometimes good enough for me. :)

Not with RTC's of course, so certainly that could play out differently - but ...... "Its entirely feasible that the fishes overall growth rate and metabolism could've been heavily, if not completely affected by its environment during the first 12" of it's life, laying a foundation for further growth that an aquarist might never be able to match." ...... could go either way with a WC fish, or captive bred, positive or negative - correct? Just looking at one thing, cortisol levels, could be high or low, for that first part of a wild or captive bred life, entirely depending on the conditions that it was growing in. So again, I think an exercise in futility.

Or am I missing something?
No you're right my part is equally subjective. Its just always occurred to me that since fish grow continuously throughout their lives, that there has to be some manipulation of this growth rate, due to either their genetics or their development, most likely both. I couldnt tell you if the key to that lies in WC vs. CB, it would definitely be interesting to have some definitive evidence though.

Maybe the people who keep this rtc know.
 
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Redtail Catfish
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That is kind of what I was getting at. I think alot of the time in CB grow outs they are fed a staple brand x chow. In the wild while harder to come by they are eating high quality live foods. I think in the first months of life this could have a huge impact on their initial development.
But I could be completely wrong also. Ive seen some breeding setup on YouTube and what not that appears they are feeding good food and have excellent filtration/water quality standards. Ive seen some videos of these hastily dug pits in some places where it looks was if they are living in mud and looks to being fed dog food.
Its just a thought.
Im guessing it all plays a role. Diet and water quality are familiar to us, but what if the key to hatching a truly monstrous rtc was imbedded in something as inconspicuous as seasonal changes in weather or photoperiod, which may in turn saturate an ecosystem with a certain type of prey, or maybe present a significant change in temperature, or perhaps even a marked drop in predation or competition during the fishes early development.
 

RD.

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I'm agreeing with much of what you gents are stating, but I still don't see what or how most of that correlates with what Reaper posted. As an example, if the majority of wild RTC reached 10 ft over the span of 50 yrs, he could be on to something, but sans that data I don't see a 5 1/2 ft RTC as being a failure - whether it was collected wild at 11", or raised on a farm to 11".
 

RD.

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Not to totally derail this RTC discussion, but this older thread is about wild vs captive sizes, with a species that has been documented fairly well. I kept and bred them for a number of years, and my friend back then collected hundreds of wild caught specimens in Africa.

 

thebiggerthebetter

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Interesting discussion. Thank you all.

Fishhead, your experiment sounds good to me. Not ideal but then nothing is. It would be hard to establish the RTC source though. Something can be definitely learned from it, just comparing the diets alone... as from the gulper experiment we have discussed seems like a year ago. Gulper is more manageable though and you can keep many of them per tank.

I personally think that you guys are overthinking this. The cat in question was under a foot when purchased, in 1972, which is 53 yrs ago...
I personally think you had had 6 beers by that moment when you calculated it out and added the beers to the years (it rhymes too!). I am 1972 and last I checked I was 47 years old :)

It doesn't change a thing though. Never mind.
 

twentyleagues

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Interesting discussion. Thank you all.

Fishhead, your experiment sounds good to me. Not ideal but then nothing is. It would be hard to establish the RTC source though. Something can be definitely learned from it, just comparing the diets alone... as from the gulper experiment we have discussed seems like a year ago. Gulper is more manageable though and you can keep many of them per tank.


I personally think you had had 6 beers by that moment when you calculated it out and added the beers to the years (it rhymes too!). I am 1972 and last I checked I was 47 years old :)

It doesn't change a thing though. Never mind.
Wheeew! I was like damnnnn I got old quick! Not that 47 isnt old or is it the new 27? Anyway thanks for clearing that up. Lol
 

RD.

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In order for any type of sensible data to be gleaned from an experiment involving fish, and growth, including longevity, one would need multiple tanks, with multiple specimens - not just a few, more like a few dozen. Obviously the more specimens, the more accurate the results, on average. Especially when it comes to sourcing the fish from the get go. Different farms, different feed, different periods of collecting wild fish (rainy season vs dry season) could and would likely result in wide variations of overall health. Rainy season brings food, dry season food supply dwindles.

The trial, or growth study would also need to be performed over a long period of time, as most commercial feed trials on record are short term, due to the fact that most studies aren't designed to examine long term anything, because the fish in question are typically destined to be eaten. They are good for extrapolating certain data, but typically fall far short of what a long term fish keeper would be interested in. At least for me. Even fools can keep a fish alive short term.

Then at the end of the trial the fish, or at least a number of the fish would require to be killed, so as a proper necropsy could be performed, which would further the portion of the long term diagnosis. This is where a closer examination for fatty degeneration of the liver, etc, could be performed.

Even if all that was done, as Viktor stated, the source of the fish would be difficult. Clearly there would mixed results due to not knowing the ages of the fish, which in this situation would be critical. Size alone would only be part of the equation, one would need to have both size, and age, in order to start on a level playing field across all specimens.

Not ideal either, but far closer to what one would need in order to collect the type of data that is being suggested.
 

Fishman Dave

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One thing I don't get in all of this talk about potential runts and throw outs from commercial farms breeding fish to feed people:-
If I were breeding a fish to feed people, I would use parents which had the best growth, the biggest fish, the fastest growing ones, and id feed the little ones up fast, ok maybe not with the best food but just like chickens, you want big uns fast and get rid.
So if the aquatics trade gets so many poor quality slow growing, smaller fish, then how???????
Where do they all come from?????I
It makes little sense that they are coming from these farms.
Or is someone trying to tell me that some expert Japanese koi breeder who can spot a show koi at 1cm from 100 yds is now in a fish farm spotting potential slow growing cats and runts at 1".
Sorry, don't buy it personally.
100,000 gal of water flowing past your whiskers per second in the wild vs 10000 gal pond (being very generous) getting even 50% water change a week is too strong an argument.

But of course, only my opinion.
 
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