Blackwater livebearers? The search continues...

Have you ever noticed that we tend to "pigeonhole" and over-generalize stuff about certain types of fishes in the hobby? 

In other words, we often make broad statements that appear applicable to an entire group of fishes, and then create a sort of cultural norm within our community that accepts without question that "this is how it is..."

I find this phenomenon as interesting as it is damaging. Interesting, because with the power of the internet, you'd think that good information could spread quickly and widely enough to help dispel some long-held, largely over-generalized, and often downright incorrect ideas. Damaging, because some of these misconceptions actually prevent talented hobbyists from not only attempting to do things, but even from discussing or "thinking out loud" about them! It's important to dig further when you have a hunch.

An example of this was when I took it upon myself to find some fishes that would work well in our acidic blackwater environments and might consume some of the occasional algae that appear in these types of aquariums. Of course, there are the typical catfishes, barbs, etc., and to a lesser extent, some species of Characins, like Headstanders, Metynis, etc., etc.- which are known to consume some algal and plant material and come from soft, acid waters. However, I wanted something a bit more unusual, a bit more "wild-looking..." 

What about some form of wild livebearer? 

Yeah, why not? I mean, some are known to consume detritus and algae, and they come from a wide range of habitats. Don't they?

However, when I delved into my initial research, almost instantly, I saw discussions amongst hobbyists that said, "No, you wouldn't want to keep these guys in soft, acidic water! Livebearers need hard, alkaline, and brackish water!" Of course, this type of extreme over-generalization is just the sort of challenge that I like to research for myself.

Now, I do understand that this is not typical of the environments from which the majority of these fishes hail, with a few possible exceptions (See "The Mystery Molly of The Amazon?" in a previous installment of "The Tint." Remember that one? Turns out it wasn't from the Amazon, but the name, oh...).

Sure, some of these fishes may be adapted to these types of environments, but they represent a small fraction of the group that are possible candidates for blackwater, botanical-style tanks. And are there any that truly inhabit soft, acidic waters in the wild?

My interest was piqued about the possibilities of finding some livebearing fishes that might come from soft, acidic environments in nature. I started doing a lot of research, in both aquarium literature and scholarly articles, corresponded with a few people who study some of the members of this group, and found a few candidates that are both interesting and perhaps even a bit surprising!

It turns out, there are some species that come from South American environments which are know to be softer and more acidic, as well as the more traditional hard and alkaline waters they're popularly known to inhabit. A few of the cool ones that I've focused my research on are:

Brachyraphis terrabensis (AKA Pseudoxiphophorus terrabensis, Gambusia terrabensis) is a possible candidate. It hails from Western Central America, like Costa Rica and Panama, in ditches and creeks, typically with water that is 7.0-7.5 pH with a hardness of 5 dGH or interesting candidate, because this is at least on the lower end of the "alkaline, hard water" scale...

Phallichthys amates, also known popularly as the "Merry Widow" Livebearer ( I say "popularly" because at least the damn fish has a "popular"'s still somewhat obscure...and not exactly "stunning" in appearance to most, but...). This one is an intriguing possibility, because it is known to come from "shallow waters with mud or litter substrata" (per're talking "stagnant waters and creeks.."- that's real encouraging (did you see that I underlined the "litter" part?)! And the fish is known to live in waters with pH between 6.0-8.0; it seems rather variable in it's habitat, although it may have been introduced into some of these more acidic waters. Hmm...

Alfaro cultratus hails from Costa Rica, Panama, and Nicaragua, and is found in Creeks and ditches waters with an average pH of 6.8, and a hardness of around 5dGH... I know a number of livebearers specialists who swear that this species does better and looks better in softer, more acidic water...particularly its reddish highlights in the scales and fins. And it does have a certain "look" that would make it fit in with those flashier fishes, doesn't it?

Of course, there are no doubt many others which come from, adapt to, and may even thrive in a blackwater environment, but these are some of the more intriguing ones I've managed to track down. Are they ideal choices? Hmm, that's hard to say. Responsible experimentation may be the best (and really only) way to determine if these fishes can truly work in our systems. Yet, it is a fun concept, isn't it? 

And let's face it, none of these are real "lookers", in terms of their bright colors or flashy behaviors. These are fishes you keep because they have a subtle beauty, an intrigue...a special "something"- like the fact that they might be a bit out of the normal, and are "off perception" for most hobbyists.

Again, I can't say with 100% certainty that these are definitely the best candidates, or even that they are great candidates for such a project, but they do seem pretty good, based on my research and the individuals with whom I've spoken who have worked with them before.

So it's time for me to hit up some of my wild livebearer-enthusiast friends and see what they're up to. These kinds of fun, speculative projects are what keep the hobby fresh and interesting to me. I may be "barking up the wrong tree" as they say...but there is something invigorating, fascinating, and even a bit inspiring about the pursuit to me...

And my advice to YOU?

Stay hungry.  Stay a bit outside the norm. Stay encouraged. Stay responsible. Stay excited.

And stay wet.

Scott Fellman

Tannin Aquatics


Scott Fellman
Scott Fellman


2 Responses

Scott Fellman
Scott Fellman

October 22, 2016

Ohhh! Another good possibility! Thanks for that tip, Joshua. I’ll check it out…And of course, I wouldn’t expect it to be EASY! LOL

Joshua Morgan
Joshua Morgan

October 21, 2016

The ginger ale livebearer is a blackwater fish…sadly, it’s NOT an easy aquarium resident. Here’s an article if it helps;

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