SPIN THE WHEEL. What color?

[duanes]

An interesting thing may have occurred with feral oscars in Florida (or here in Panama) where they are commonly found.
With the attrition of those unable to adapt to the normal hard water, the feral oscars may be better adapted to normal aquarium life, in hard water tanks.
Those not able to adapt, would be naturally culled, allowing only those able to adapt, to reach maturity, to breed, and produce more of the same.
They are a common occurrence in Lake Gatun, where pH often hits 9, and salinity rises and falls with the opening and closing of the Panama Canal locks.
I believe this natural culling is a much more effective way of adaptation, compared to tank breeding where often, weak individuals are allowed to survive because of the closed systems, and where successful Oscar breeders would tend to cater to natural South American soft water needs.

 

[FINWIN]

IMO what you should avoid, is anything that has been bred, or in anny way originates from SE Asia.
Unless you are seeking weak genetics, but showy looking fish. Much like flowerhorns, bred for their beauty, not longevity.

I would focus on wild type, even feral O’s out of a canal in FL before buying fish sourced from Asia.

Good luck

I thought most of the issues out of that region were with the flowerhorns not oscars? Can't recall.

 

[FINWIN]

An interesting thing may have occurred with feral oscars in Florida (or here in Panama) where they are commonly found.
With the attrition of those unable to adapt to the normal hard water, the feral oscars may be better adapted to normal aquarium life, in hard water tanks.
Those not able to adapt, would be naturally culled, allowing only those able to adapt, to reach maturity, to breed, and produce more of the same.
They are a common occurrence in Lake Gatun, where pH often hits 9, and salinity rises and falls with the opening and closing of the Panama Canal locks.
I believe this natural culling is a much more effective way of adaptation, compared to tank breeding where often, weak individuals are allowed to survive because of the closed systems, and where successful Oscar breeders would tend to cater to natural South American soft water needs.
View attachment 1538340View attachment 1538341

Interesting. I'll be making inquiries about source water from sellers. PH here in DC averages 7.5. Considered moderately hard.

 

[RD.]

I thought most of the issues out of that region were with the flowerhorns not oscars? Can't recall.

Same dynamics at work - fish are bred for fancy colors, showy traits, not longevity. Hormones are still commonly used on juvenile cichlids, to bring out maximum male coloration at early ages. etc.etc.etc

 

[RD.]

Genuine aquatic science, not some guy who fancies himself as the father of all fish keepers or a guy with a blog who fancies himself to be a science authority. And while I'm always for keeping nitrates as low as you reasonably can, consider how this accounts for (some of) the varying opinions (and results) regarding nitrate levels-- and why some fish may seem to be more sensitive than others.

Simultaneous exposure to nitrate and low pH reduces the blood oxygen-carrying capacity and functional performance of a freshwater fish | Conservation Physiology | Oxford Academic (oup.com)

Blaming pH as the main cause of HITH in species such as Oscars is old school thinking, IMO it seems far more probable that pH is seldom the actual stress trigger that causes most cases of HITH in fish. HITH is a symptom, the same as bloat in fish. Old school logic blamed incorrect diet in causing bloat, which we now know is seldom the stressor at play when bloat strikes.

 

[FINWIN]

Blaming pH as the main cause of HITH in species such as Oscars is old school thinking, IMO it seems far more probable that pH is seldom the actual stress trigger that causes most cases of HITH in fish. HITH is a symptom, the same as bloat in fish. Old school logic blamed incorrect diet in causing bloat, which we now know is seldom the stressor at play when bloat strikes.

I've seen these...went through all of his vids during the time I struggled healing my bp Patch. Very knowlegeable...too bad there aren't more fish vets in my area. I hear its really lucrative.

 

[duanes]

I do not blame pH alone, especially when dealing with higher animals like fish, but.....
what I have seen as a former microbiologist, is that certain bacteria become more virulent in certain water parameters.
In the low pH waters of Amazonia, fish species have not needed to evolve resistance to certain bacteria, that proliferate in hard, mineral rich, (and often times) higher pH water.

So if you take a fish like an oscar, Uaru or P-bass or other species endemic to the low mineral content, low pH waters of Amazonia, and place it in high pH, and high mineral content waters in North America, it often has little resistance to the bacteria endemic to those mineral rich waters.
I don't suggest that it's the waters pH alone, but......it's the lack of resistance to the bacteria that are endemic to many N American waters.
The bacteria that cause HITH do best in a pH range of 7.5 and above, so if you place a soft water, low pH fish species in hard higher pH water, the probability that a chronic HITH infection, becomes likely over time.
This is often bourne out in posts in the disease section, such as....
"My oscars were doing great, I haven't done anything different, and some mysterious disease hit" out of nowhere. Etc, Etc,
But here again, its not simply one cause, when you look at the parameters many posters relate,
Beside elevated pH and hardness, nitrate is also elevated , and my experiments in the lab have shown that the bacteria that initiate HITH infections thrive in high pH, high mineral content and high nitrate waters ( any nitrate of 5 ppm and higher, is a virtual HITH soup.

If over time, those same species have been allowed to breed in places such as the natural waters in Florida, or Lake Gatun those fish without resistance are quickly weeded out by the gauntlet of the "survival of the fittest" mode only allowing resistant individuals to breed and carry on, those resistant genes.

I was watching a video of Dan from COA not long ago, who stated Kronoheros umbriferus from the soft waters in the Magdalena river system are often plagued by fungal and bacterial maladies if placed in hard, high pH water, and that he went out of his way to give them perfect soft water, low pH conditions in his facility.

 

[RD.]

Precisely, so instead of always laying the blame on pH values, imo better to explain to hobbyists that bacteria, in this case to simplify, measured using Nitrates, should be close to zero at all times. Older fish become victims to HITH as the bio load, and bacteria count elevate over time. This might be a chicken/egg thing, but many of these fish can be successfully kept in harder water with pH of 8.0, IF the fish keeper keeps bacteria to a minimum. I know this, because I have seen it done. Not easy as the fish mature, but doable to those dedicated enough to keep low stock, and frequent water changes. Or at the least, mention the entire scenario, because with these fish ultimately it is the bacteria that causes the illness, not the pH.

 

[FINWIN]

Isn't there such thing as ph shock, though? I remember getting a beautiful sun catfish (11 inches) that I couldn't save in four hours before he just rolled over. Never even made it to quarantine. Same temp, prime added. No good. Once he was out of the bag water it was over. Lost two goldspot plecos the same way and haven't bothered with them since...all purchased at the same location.

 

[duanes]

The chronic effects pf pH are seldom a direct route, they are a normally indirect route, thru the chronic bacteria exacerbated by elevated nitrate.
For certain sensitive species, a drastic crash could be fatal though, especially for those species that are endemic to those very stable bodies of water, such as the African rift lakes.
Riverine species are often more tolerant, but....as an isolated example
I have been testing pH on the Mamoni river since April of 2023, when pH measured 8.2.

The largest swing, so far has been a drop to 8.0, just the other day.

You may also notice, the nitrate level has remained the same (non-detectable) in all tests