Biotope Op Ed

[duanes]

After 7 decades of fish keeping, I have become more and more anal about what species of fish I keep together, in the same tanks.

I became even more persnickety, after ending up in a career as a water chemist/microbiologist, realizing the vast differences in water types, the sensitivity of certain fish to pathogenic bacterial species, in even seemingly benign and minor water parameter differences, and idiosyncrasies.

Parameters such as pH, and hardness, all come into play, indirectly influencing the health of fish we keep, because of bacterial immunity, or the lack thereof.
For example…
Fish from acidic, soft waters, are not immune to same species of bacteria, found in high pH, hard water (and visa versa ).



But…
I also realize though, (as a hobbyist) that its not just about water chemistry, or science, its about what’s under water, its what’s above the water, its about the fishes territorial needs. Its about proper substrate,

It’s about the entire habitat coming into play, and that is what makes it challenging and keeps it interesting (at least to me).
It also may mean the just because fish share the same continent, doesn’t mean they share, or are healthy in the same habitat.

Cichlid species such as Gymnogeophagus from the temperate waters of Uruguay and Argentina, (where there is sometime snow in winter) do not belong in the same tank with tropical Amazonian species like severums, or Angelfish, where there are constant water temps in the 80s´F, even though they are all S Americans, and beyond the differences of pH and hardness, north to south.

Above a winter scene in Argentina.
Or that Denison barbs and White cloud mountain minnows from cool 65¨F water streams in the highlands of India, or China, do not belong in the same tanks with Bettas from the lowland rice paddies of Viet Nam, or Cambodia, much less the 82 +F waters in Central America, or in Amazonia.

 

[duanes]

So, you may ask, what relevance does this have to the tiny puddles we force our fish to endure in closed constantly recirculating glass box systems?
To me it means, if we, as custodians of the fish we keep, should provide similar and adequate water parameters,
those they would similarly exist, and are close to habitats they evolved to live in in nature, if at all possible.
Because those tiny puddles tend to exacerbate water quality lapses, not mitgate them

So if its all about maintaining correct parameters such as pH, hardness, nitrate, temp, and flow rates,…….whatever we can do to emulate an ideal natural setting within reason.

But does it mean we should chase water parameters?
Actually no…..but it does mean, is choosing the correct species, that match our tap water.
It means if we are blessed with low pH, soft water,
those are probably the species we are meant to keep. (such as S American Amazonian's, west Africans, or S East Asians)
or
if we are blessed with hard, high pH water, fish from the Rift lakes of Africa, or high pH waters of Central/North America would be apropos.

It is (of course) possible to fight our water chemistry, but that means essentially, putting on a chemists hat, and doing continuous water parameter tinkering, and adjusting to keep the our fish healthy.
And not to figure, that 50 or 100 years of life in somebody’s aquarium, negates several million years of evolution to a specific habitat.

But ....what if I really want severums, or Cardinal tetras, yet my water is hard and has high pH?
There are reasonable facsimiles of species, adapted to many waters around the world to choose from..


Above are Etroplus suratensesus, very similar , in that it is primarily a vegetarian, (much like severums), get the same size, and prefer to live in shoals (like severums do), and come from similat water temps,
but the ones above, come from the higher pH, hard water of India, and can even handle brackish conditions.
If I didn´t ID them, would you know, they are not severums? I¨m sure some would, of course
but if you have hard, high pH water, whats better, severums scarred up with HITH, or those above.




Above are Roeboides and Astyanax tetras found in the hard high pH waters from Panama to Mexico…… maybe not quite as electrically colored as Cardinals, but would you rather have tetras that live, or die at the drop of a hat, if you have high pH, and hard water.

 

[justintheodd]

So, you may ask, what relevance does this have to the tiny puddles we force our fish to endure in closed constantly recirculating glass box systems?
To me it means, if we, as custodians of the fish we keep, should provide similar and adequate water parameters,
those they would similarly exist, and are close to habitats they evolved to live in in nature, if at all possible.
Because those tiny puddles tend to exacerbate water quality lapses, not mitgate them

So if its all about maintaining correct parameters such as pH, hardness, nitrate, temp, and flow rates,…….whatever we can do to emulate an ideal natural setting within reason.

But does it mean we should chase water parameters?
Actually no…..but it does mean, is choosing the correct species, that match our tap water.
It means if we are blessed with low pH, soft water,
those are probably the species we are meant to keep. (such as S American Amazonian's, west Africans, or S East Asians)
or
if we are blessed with hard, high pH water, fish from the Rift lakes of Africa, or high pH waters of Central/North America would be apropos.

It is (of course) possible to fight our water chemistry, but that means essentially, putting on a chemists hat, and doing continuous water parameter tinkering, and adjusting to keep the our fish healthy.
And not to figure, that 50 or 100 years of life in somebody’s aquarium, negates several million years of evolution to a specific habitat.

But ....what if I really want severums, or Cardinal tetras, yet my water is hard and has high pH?
There are reasonable facsimiles of species, adapted to many waters around the world to choose from..

View attachment 1566977View attachment 1566976
Above are Etroplus suratensesus, very similar , in that it is primarily a vegetarian, (much like severums), get the same size, and prefer to live in shoals (like severums do), and come from similat water temps,
but the ones above, come from the higher pH, hard water of India, and can even handle brackish conditions.
If I didn´t ID them, would you know, they are not severums? I¨m sure some would, of course
but if you have hard, high pH water, whats better, severums scarred up with HITH, or those above.

View attachment 1566978
View attachment 1566979

Above are Roeboides and Astyanax tetras found in the hard high pH waters from Panama to Mexico…… maybe not quite as electrically colored as Cardinals, but would you rather have tetras that live, or die at the drop of a hat, if you have high pH, and hard water.

Well said Duanes, I should probably be a little better about this, seeing as I have convicts and a green terror in ph 8.2 water.