April 05, 2020

Bringing it home..

As a practitioner of the natural, botanical-style aquarium, I am a rather vocal proponent of creating more naturally appearing- and functioning habitats for our fishes. I am a big believer that our fishes, which have evolved over eons to live in specific types of environmental conditions- will ultimately do best in captivity when provided with them.

During our amazing conversation with Mike Tuccinardi on our recent podcast version of "The Tint", Mike mentioned that, at least initially, you don't need give your newly-imported fishes the exact environmental conditions that they came from in order to be successful with them. Mike indicated that it's far more important initially to provide clean, high quality water, as most fish from the soft, acidic blackwater habitats simply don't have the resistance to pathogens.

The idea been that, although tannins in the water can help during the earliest phases of quarantine and acclimation, it's more important to offer high quality water than exact replication of their wild habitats. However, once acclimated, Mike has pointed out the manifold advantages of keeping fishes in water conditions which resemble those found in their natural environment.

Yeah, that makes a ton of sense.

And you know I've always been a fan of sort of "re-adapting" or "re-patriating" even captive-bred specimens of all sorts of fishes (like "blackwater-origin" characins, cichlids, etc.) to more "natural" conditions (well, "natural" from perhaps a few dozen generations back, anyhow). I am of the opinion that even "domesticated" fishes can benefit from providing them with conditions more reminiscent of those from the natural habitats from which they originated.

Although I am not a geneticist or biological ethicist, I never will buy into the thought that a few dozen captive generations will "erase" millions of years of evolutionary adaptation to specific habitats, and that re-adapting them to these conditions is somehow "detrimental" to them. Something just seems "off" to me about that thinking.

I just can't get behind that.

Now, even more compelling "proof" of that it's not so "cut-and-dry" is that many of the recommended "best practices" of breeding many so-called "adaptable" species are to do things like drop water temperatures, adjust lighting, or perform water exchanges with peat-influenced water, etc....stuff intended to mimic the conditions found in the natural habitats of the fishes...

I mean...WTF? Right?

Like, only give the fishes their "natural" conditions when we want to breed them? Really?

That mindset just seems a bit odd to me...

Of course, there are some fishes for which we don't really make any arguments against providing them with natural-type environmental conditions from the 'get go", such as African rift lake Cichlids. I find this absolutely fascinating, from a "hobby-philosopher" standpoint!

Like, it's a given, right?

And then, there are those fishes which we have, for various reasons (to minimize or prevent the occurrence of diseases) arbitrarily decided to manipulate their environment deliberately away from the natural characteristics under which they evolved for specific reasons. For example, adding salt to the water for fishes that are typically not known to come from brackish habitats.

Examples are annual Killifishes, such as Nothobranchius, which in many cases don't come from brackish environments naturally, yet we dutifully add salt to their water as standard practice. The adaptation to a "teaspoon of salt per gallon" or so environment is done for prophylactic reasons, rather than what's "convenient" for us- a rather unique case, indeed...and again, something that I find fascinating to look at objectively.

Is salt simply the easiest way to prevent parasitic diseases in these fishes, or are there other ways which don't require such dramatic environmental manipulations? Like, is it that difficult to eliminate possible pathogens in their aquarium while keeping them in water conditions which are more reminiscent of that which they come from naturally?

I don't think that it is.

And then, of course, there are those unexpected populations of fishes, like various Danios and Gold Tetras, for example, which are found in mildly brackish conditions...Compelling, interesting...yet we can't conclude that all Gold Tetras will benefit from salt in their water, can we?

No, of course not.

And, as we evolved to a more sustainable hobby, with greater emphasis on captive -bred or carefully-sourced wild fishes, and as more wild habitats are damaged or lost, will we also lose valuable data about the wild habitats of the fishes we love so much? Data which will simply make the "default" for many fishes to be "tap water?"

I hope not.

Is it possible, though, that we've been so good at "domesticating" our fishes to our easier-to-provide tap water conditions- and our fishes so adaptable to them- that the desire to "repatriate" them to the conditions under which they've evolved is really more of a "niche" thing for geeky hobbyists, as opposed to a "necessary for success" thing?

I mean, how many Discus are now kept and bred exclusively in hard, alkaline water- markedly different than the soft, acid blackwater environmental conditions under which they've evolved for eons? Am I just being a dreamer here, postulating without hard data that somehow the fishes are "missing something" when we keep and breed them in conditions vastly different than what the wild populations come from?

Do the same genetics which dictate the color patterns and fin morphology also somehow "cancel out" the fish's "programming" which allows them to be healthiest in their original native conditions?

How do we reconcile this concept?

DO we?

In the end, there are a lot of variables in the equation, but I think that the Nothos and Discus discussion is an example of fishes which could perhaps benefit from experimenting with "throwback" conditions. I'm by no means anything close to an expert on either of these fish, and my opinions are just that- opinions.

Commercially, it may not be practical to do this, but for the hobbyist with time, resources, and inclination, it would be interesting to see where it takes you.

Like, would the same strain kept in both brackish and pure freshwater habitats display different traits or health characteristics?

Would there even be any marked differences between specimens of certain fishes kept under "natural" versus "domesticated" conditions? Would they show up immediately, or would it become evident only after several generations? And again, I think about brackish-water fishes and the difficulty of tracing your specimens to their natural source, which makes this all that much more challenging!

I look forward to many more such experiments- bringing natural conditions to "domesticated" fishes, and perhaps unlocking some more secrets...or perhaps simply acknowledging what we all know:

That there truly is "no place like home!"