The non native convict cichlid

[duanes]

Are the invasive oscars showing HITH in Panama's hard water areas? or are they primarily in soft water areas of Panama? Or both?

What about the cichla?

Since both oscars and Cichla have been here in Panama since the 1960s, I believe survival of the fittest has culled any individuals that couldn't handle and adapt to the hard water off over 60+ years, perhaps millions died to be able to be successful at handling those parameters before a self sustaining hard water population was developed.
I would imaging the same way Florida Oscars have adapted over the decade there.
This is a far cry from taking a soft water species and trying to force it to live in adverse conditions in only 1 or 2 generations.
As far as Cichla, they do well but only reach about 2/3 the size of their Amazonian counterparts, but the other worse consequence since their introduction here, the native population of fish are down 96%, and species diversity is down 64%.

 

[Rocksor]

Since both oscars and Cichla have been here in Panama since the 1960s, I believe survival of the fittest has culled any individuals that couldn't handle the hard water off over 60+ years, perhaps millions died not able to handle those parameters before a self sustaining hard water population was developed.
As far as Cichla, they do well but only reach 2/3 the size of their Amazonian counter parts, but since their introduction the native population of fish are down 96%, and species diversity is down 64%.

So would it be safe to assume that aquarium strain oscars haven't received the same hard water parameters on a constant basis as the Panama ones? I haven't seen anyone write that they were able to breed oscars and produce viable fry in aquarium hard water.... or maybe it's something else like nitrates being too high that prevents it. Obviously it happens in Florida's water system.

 

[ryansmith83]

Most natural Florida waterways, especially through swamps and wetlands, are soft and acidic. Ground water from the aquifer is hard because of the limestone infrastructure beneath the state, but this doesn’t affect groundwater much except in springs that are aquifer-fed.

In Florida, cold snaps are more likely to kill feral New World cichlids than the pH/hardness. A few years ago Miami had an extended bout of unusually cold weather and it killed off a ton of invasives, including iguanas and cichlids.

 

[duanes]

So would it be safe to assume that aquarium strain oscars haven't received the same hard water parameters on a constant basis as the Panama ones? I haven't seen anyone write that they were able to breed oscars and produce viable fry in aquarium hard water.... or maybe it's something else like nitrates being too high that prevents it. Obviously it happens in Florida's water system.

In most cases of aquarium strain individuals, having problems, it often can't be pinned down to just one factor, but instead a number of combining problems.
We've all seen some aquarists that are able to keep a generally soft water species healthily in hard water, or high pH water (maybe not successfully raise fry, but keep them nonetheless) .
But on the disease forum, is often filled with those (especially oscars) that end up with HITH after a couple years, as that species ages.
It may be hard water in combination with above average nitrate (or other(?) intangibles, that may be the determining factor(s).
When I have done tests on the natural waters in my area where oscars thrive as feral, like Gatun and other areas in Central and eastern Panama, the pH averages above 8, mineral content is high, but nitrate are usually undetectable. Even though water is not necessarily pristine looking and clear, parameter tests are.
Below Lake Gatun,, where they thrive.

 

[Rocksor]

In most cases of aquarium strain individuals, having problems, it often can't be pinned down to just one factor, but instead a number of combining problems.
We've all seen some aquarists that are able to keep a generally soft water species healthily in hard water, or high pH water (maybe not successfully raise fry, but keep them nonetheless) .
But on the disease forum, is often filled with those (especially oscars) that end up with HITH after a couple years, as that species ages.
It may be hard water in combination with above average nitrate (or other(?) intangibles, that may be the determining factor(s).
When I have done tests on the natural waters in my area where oscars thrive as feral, like Gatun and other areas in Central and eastern Panama, the pH averages above 8, mineral content is high, but nitrate are usually undetectable. Even though water is not necessarily pristine looking and clear, parameter tests are.
Below Lake Gatun,, where they thrive.
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Does the mineral content and PH in Lake Gatun go down during rainy season in Panama?

 

[duanes]

I have not been out on Lake Gatun to check during the heavy rains,
Bu when I have checked direct samples of rain, they've remained at pH of @8.2.