Geophagus sveni question.

[Jonnyakawombell]

Hi all just a very quick question regarding Geophagus sveni, as unfortunately there's far to much conflicting information online, what is the max size they generally reach in captivity on average (growing them on from small), really interested in people experience's that may have done this in the past, many thanks for your time.

 

[PhishMon84]

My two largest were around 8-10" after a few years in a tank, starting at 3" size.

 

[bkfamus]

my 3 largest ~8-9". I'm not sure if they stopped growing.. had them since the end of 2022 and bought them at 3".

 

[duanes]

Size is somewhat subjective, because there are so many variables aquarists tend to abide by.
If you change 25% of your tanks water once per week for instance, Geophagines tend to grow much slower than if you change 100% of your tanks water once per week.
In rivers where they come from, nitrates are usually lower than 5 ppm, so if your maintain nitrate levels at 10 or 20 ppm, your fish may tend to grow slower and smaller than if your nitrates at below 5 ppm, like their natural parameters
In rivers where G sveni come from pH is usually 7 or below, with soft water, but if your water parameters are harder and pH is higher than 7.5, yours may not achieve the same potential that those kept in parameters. more akin to their natural norms.
Most of the time I see aquarists maintaining Geophagine sveni in the 7 to 8" range.
With my 100% per week water change schedule, and low nitrate conscentrations most Geos I have kept long enough, and reach 12" , are quite normal.

 

[Jonnyakawombell]

Size is somewhat subjective, because there are so many variables aquarists tend to abide by.
If you change 25% of your tanks water once per week for instance, Geophagines tend to grow much slower than if you change 100% of your tanks water once per week.
In rivers where they come from, nitrates are usually lower than 5 ppm, so if your maintain nitrate levels at 10 or 20 ppm, your fish may tend to grow slower and smaller than if your nitrates at below 5 ppm, like their natural parameters
In rivers where G sveni come from pH is usually 7 or below, with soft water, but if your water parameters are harder and pH is higher than 7.5, yours may not achieve the same potential that those kept in parameters. more akin to their natural norms.
Most of the time I see aquarists maintaining Geophagine sveni in the 7 to 8" range.
With my 100% per week water change schedule, and low nitrate conscentrations most Geos I have kept long enough, and reach 12" , are quite normal.
View attachment 1559051

I do 50% water changes every 48 hours so I should be good that way as nitrate has never exceeded 5ppm, the water comes out my tap at ph 7 and relativity soft also, so with that info you gave me I should be eventually getting some big geophagus, although my plan has altered slightly as my supplier has managed to source me 6 wild caught one's at around the 7" size range, rather than the 3" size rate I was going to get, so basically when there done with quarantine they can go straight in the arowana tank, thanks for your great response.

 

[neutrino]

Geo species vary in size, you won't see 12" pindare or pyrocephalus, no matter how many water changes. On average altifrons are on the high end of the scale. Similar to several other species, sveni generally get moderately large, 8,9 inch males are pretty common, some get larger, I've seen them 11 inches, but the average is a bit less. I've seen native fishing photos of nice, fat 8 inch sveni. Females tend to end up a bit smaller, but you don't always see this after their first year. I've had females that were among the largest in the group, then pair up, male and female equal in size, after which the male gradually outgrew her over the next year or two.

Clean water is important, but it's just one piece of the pie. Mineral balance, oxygen levels, temperature in the correct range, nutrition, and individual genetics all play a part. Not all individuals reach the maximum potential size for a species, so not getting a 10 or 11 inch sveni doesn't mean you've done something wrong. No one says we must have been fed and raised improperly if we're not 7 feet tall. The real proof of quality fish care, assuming healthy specimens to begin with, is good health and longevity.

 

[neutrino]

...Just to illustrate that, yes, we can influence growth by providing good conditions, but there are limits: In 1949 it was predicted that with plenty of vitamins and sunshine and based on average height growing in modern times (typically attributed to better nutrition and health care), women would all be 6 ft tall.

 

[troublesum]

...Just to illustrate that, yes, we can influence growth by providing good conditions, but there are limits: In 1949 it was predicted that with plenty of vitamins and sunshine and based on average height growing in modern times (typically attributed to better nutrition and health care), women would all be 6 ft tall.

Look at the WNBA

 

[neutrino]

Look at the WNBA

The 1949 prediction was that all women would be 6 ft.