The great killifish conundrum...

There are certain fishes in the aquarium world that will simply grab ahold of your attention and not let go. For me, it's been characins and killifish. Yeah, killifish! The seemingly forgotten, yet utterly engrossing group with amazing colors, diverse spawning habits, and adaptability should make them some of the most popular fishes in the hobby!

Yet, they're most definitely NOT.

To me, the reasons above and many others have kept them "top of mind" for me over the years, even though I may not always have kept them consistently.Their relative difficulty to obtain has sort of added to the mystique for me. That and the fact that they typically will not have "common names", and are generally referred to by their scientific name, followed by a geographic locale and some other numbers makes them all the more alluring to me!

Hmm... "geographic locales" never scared anyone...

Yet, I digress... these arcane names don't help in the splashy, superficial "Insta world" of social media that we've created I the 21st century, I admit.

I mean, shit- there's like 0.000034% chance that a fish with a name like "Austrolebias arachan, UYRT 2015-04" is EVER gonna knock off the Cardinal Tetra or Angelfish and crack the "Hot 1,000" list of the most popular aquarium fishes, right? 

Yet, the precise Latin descriptors and type localities bely a secret to those who do the work...they give us information of incalculable value about the specific biotope/habitat from where the fish hails from. And to those of us who strive to replicate- on many levels- the wild habitats from which our fishes come from, this stuff is pure GOLD! 

(Chromaphyosemion bivittatum, pic by Mike PA Calnun)

And of course, one of the things I like best about killifishes is that many come from habitats that would be perfect for us to replicate with our skills and interest. Hobbyists who keep killies may not be as into the aesthetics of blackwater or botanical-style aquariums as we are, but nonetheless, they understand the dynamics of using natural botanical materials like peat moss, coir, and leaves to stimulate spawning and provide health benefits for their fishes!

Perhaps what also attracts me to them is the fact that they are (for the most part) small, super-colorful fishes who have managed to adapt and evolve to life in very unusual environmental niches, like puddles, small creeks, temporary pools- stuff like that. And of course, these are extremely "botanically-influenced" habitats, replete with leaves, soil/mud substrates, branches, etc. The killies are intimately linked to the characteristics of their habitats, and the seasonal changes which impact them. 

It's utterly fascinating.

(Kwango Province, Congo- Image by Thomas Minesi)

Interestingly, we have seldom, if ever seen them being kept in anything other than a dedicated breeding setup with spawning mops and bare bottoms. I think this has perpetuated the popular perception that they require the dreaded "specialty conditions" (hobby vernacular for "weird shit that's hard to do..."), and the need for 200-tank setups that will turn you into the aquarium version of the "crazy cat lady", thus smashing your interpersonal relationships to pieces. And of course, this pretty much scares the crap out of the typical armchair hobbyist.

That's where we come in.

I think that attempting to replicate, to some extent, the aquatic habitats from which they come would go a long way towards making these adaptable and attractive fishes more popular in the hobby! And instead of 300-odd  plastic shoeboxes filled with killies, you might have like 6 different "biotope-inspired" aquarium for killies (I say that now...). How you manage your interpersonal relationships is your call- but I think we make it a bit easier with our approach, right? 😆

(Fp. amieti, pic by Mike PA Calnun)

Sure, some may be shy, skittish, aggressive, come from soft, acidic water, brackish(!), or whatever- but the last time I checked, we have community of skilled, adventurous aquarium hobbyists playing with blackwater, botanicals, and the availability of all sorts of "twigs and nuts" to create these kinds of specialty tanks. And we're into some pretty geeky stuff, ourselves, right?

We can keep these fishes with ease, so...

We often hear the argument that they are not particularly prolific breeders, or don't live too long (in the case of "annual" species, sure...but how many years have you kept a Cardinal Tetra alive for?). I think that's a really lame excuse not to keep them!

(Fp. gardneri in a natural setup. Image by Mike PA Calnun)

My other "counterpunch" here is that, curiously, we're seeing more and more wild Betta species showing up in local fish stores worldwide...Really friggin' obscure ones, too...And SOMEONE is breeding them. And they are finding a place in botanical-style, blackwater aquariums!

Yep. Killies can, too.

And if we look at some of the more popular killifishes, such as the Aphyosemion, Chromaphyosemion, and Funduloopanchax species, there are a variety of ecological adaptations to their environments that have made them extremely compelling subjects for those of us interested in creating natural-type setup for them. 

(Mike PA Calnun's African killie and Neolebias biotope-inspired aquarium is a fantastic example of the possibilities that await the adventurous killie enthusiast when we step out of the box a bit!)

Granted, this is different than what "hardcore" killie breeders will do- and not as efficient for breeding as setting them up in bare tanks/plastic sweater boxes with spawning mops- but it's a different way to enjoy these unique fishes, and to celebrate the unique ecological niches from which they come!  I simply don't think that we as killie fans have done a great job "de-mystifying" these fishes and their needs. As mentioned above, we have seldom, if ever see them being kept in anything other than those "utilitarian-looking" dedicated breeding setups with spawning mops and bare bottoms- and lots of people assume that is THE way.

It's not.

It's time to kick that unfair reputation that killies have earned to the curb, once and for all.

Now, there are literally hundreds of species of killies to choose from, running the gamut from top-spawning species which deposit eggs in floating plants, to the famous South American and African annuals, which deposit their eggs in the mud and sediments at the bottom of the temporary pools which they inhabit, so it would be impossible to "generalize" a biotope-inspired "generic" setup for all these types. However, one could create a more-or-less "generalized" setup for say, species which come from small African streams and pools. 

(Aphyosemion over leaf litter Wamba, DR Congo- image by Ashley Gordon)

For many of the Aphyosemion and Fundulopanchax species, you can replicate their leaf-and branch-choked habitats with, well- leaves and branches! And seed pods, and a few aquatic and even terestrial plants. We do this shit pretty well already...don't we?

Researching the flora and aquatic topography of areas in Camaroon and Nigeria can yield lots of great information which you can use to create some really cool tanks! In general, Africa has been, in my opinion, under-represented in our aquariums, and killies represent an amazing opportunity to learn more about these habitats and the unique fishes which inhabit them.

(Fp. gardneri Pic by Mike PA Calnun)

Many of these streams and pools feature muddy or fine-sediment materials on the substrate. You could replicate this with many of the planted aquarium substrates, mixed in with more common materials like sand and even our "Fundo Tropical" and "Susbtrato Fino" additives, or the more "igapo-specific" substrates we'll be releasing soon...

With some good research and study, it is entirely possible to create remarkably realistic and functionally aesthetic aquariums for many species of killifish. And the concept is simply no different than anything else we do for any other fishes in our blackwater/botanical-style aquariums. 

We just need to get the fishes. And you can, easily, from breeders in places like AquaBid, or; go all the way and join The American Killifish Association and really get to know some of the amazingly skilled hobbyists happily playing with these amazing fishes. You'll find a global community happy to lend you a hand, answer questions, and sell you some fishes or eggs to get you started on your way.

(The topography and flora of Camaroon contribute significantly to the aquatic habitats of the region. Image by C. Hence, used under CC BY-SA 3.0)

Obviously, a little blog piece like this can do little more than call some quick attention to the possibilities that are out there for this approach. My hope is that more of you will utilize the skills you've acquired at both keeping and breeding fishes and working with botanical-style aquariums. By marrying these two skill sets, the possibilities which can unfold are many!

We just need to get out there, do a little research, and get a tank or two going. Oh- and we need to share this work. On the "big stage"- the more generalized hobby world-outside of dedicated hardcore killie forums and pages. 

Let's look at some of these unique fishes and the habitats from which they come, and give them more of the attention they deserve in the hobby! 

Killies can totally be getting their fair share of expose to the larger hobby world. Killie lovers need to let go of 1978-era excuses and complaints about why they aren't out there, and simply share these fishes in more unique, relatable ways. We can't keep "self-medicating" on excuses and complain about it when the opportunity is there to "blow up" interest in these fishes! There's these platforms called ""Facebook and "Instagram" and "Snapchat"- crazy-ass ways to spread ideas quickly...We should look 'em up once in a while, post something on a general hobby-interest forum- like a pic and descriptions of a cool display tank with killies- and get people talking.

We should.

It just hasn't been happing...Not enough, anyways.

Why aren't we doing this? George Farmer, "The Aquascaper" himself put down a Killie tank for the ages not long ago...That tank should have inspired thousands!

I won't accept the excuse that, "Oh, I tried it before but no one was interested." No, you didn't do it in an effective way that conveys the wonder and fascination of these fishes to a wider audience, and as a result, interest in these fishes is still needlessly relegated to the darker, more specialized corners of the hobby. 

Hmm, sounds like what was said about...blackwater aquariums...or brackish, for that matter before we all decided to bring it out of obscurity, doesn't it?

Yeah, it does. And we know how that's sort of working itself out, right?

We can do this.

Just seeing an aquarium set up to replicate, say, a small vernal pool in West Africa, housing fishes from the genera Epiplatys, Rivulus, Fundulopanchax, or Aphyosemion- amazingly colorful, small, and interesting fishes- would blow away just about everyone in the hobby who has been on the fence about them for years! And really researching a proper biotope- or biotope inspired tank could teach the hobby and the non-hobby world alike about these amazing fishes and their  often fragile habitats. And their unique reproductive strategies (as in the case of annual species and "bottom spawners") are amazing in and of themselves. 

Oh, and you can economically purchase most of them as eggs (in water or peat moss) and raise them from fry yourself, easily and sustainably, as touched on before. One of the worst-kept hobby "secrets" there is, IMHO.

And these fishes are OUT there. Hello, American Killifish Association! Hello, killie hobbyist forums on Facebook. Hello Aqua Bid!

I'm sorry if I'm coming across a bit "harsh" on this.

I can see how some people might take this little kick in the ass in the wrong way- but I think that this "tough love" and request for us to look at what we're not doing well enough- from a big fan, no less- is warranted. I just get tired of hearing the same excuses for stuff with no new action being taken- especially when the excuses are made by incredibly talented people who can bring so much to the table...

Enough. 1978 is 40 years in the past. Time to work on the future!

Who's in?

We all should be. Killifish are some of the absolute best examples of sustainability, responsibility, and dedication that the aquarium world has to offer. They teach patience, inspire research, and are an amazing group of fishes to specialize in.

Let's show them the love they deserve!

Stay excited. Stay resourceful. Stay diligent. Stay inspired...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


5 Responses


March 23, 2024

What a great article! I’ve only recently (few days ago) stumbled upon the world of killifish and I’m already VERY interested in them and even considering keeping/breeding them. I first stumbled upon them on the internet  where I saw nothobranchius eggs for sale. I never knew fish eggs could be sold/mailed and so I became intrigued. After doing a deep divide into their biology, lifecycles and breeding, I’ve found it all extremely fascinating! 

I then had the exact same thought as you – why aren’t these fish more popular than they are? They’re insanely colourful. They’re very interactive when raising them from the egg. And, from the little I know, there seems to be at least a few good beginner species available out there. The excuse some people make saying that some of them don’t live very long is weaker than a wet tissue. The all too popular betta and guppy breeds now-a-days are just as short lived as the annual killifish plus there are, of course, non-annual killifish species that will fare out live any guppy and possibly see out two bettas’ life times before one killifish dies. What I suspect may be the case as to why people make lame excuses as to why “it’s not worth it”, especially by experienced aquarists of all people, is that breeders fear the possibilities of killifish hybridization if they become popular with more amature aquarists and end up like betta and guppies breeds today. It seems to me that many killifish breeders (especially from the AKA) are extremely focused on not mixing strains, even within the same species, so perhaps there is some somewhat purposeful discouragement going on?……and hence why unexciting, complicated names are always used to focus solely on species strain integrity rather than appealing to a wider audience outside breeders?

Don’t get me wrong, I am all for species integrity but I’m also all for supporting aquarists in correctly introducing them into various areas of this amazing hobby. I think there needs to be more accurate information on them spread more so than the technical problematic possibilities associated with the species family. As well as, like you mentioned, showcasing their absolute beauty in colour and nature in biotype style aquariums. Nothing sparks more intrigue than seeing an animal in its natural element.

I still believe, like you, that there is a big market here. For me in Australia, there are very limited options for various killifish species one can buy within my country. If you’re old enough to remember the brine shrimp (or should I say “sea monkeys”) craze that excited many people at the thought of being able to hatch and raise their own pets, would not killifish eggs be just as exciting for the majority of people?!  

I may not have much credibility seeing that I haven’t ever kept a killifish (yet) but, after reading your article, I totally understand your frustration regarding this unfortunate hidden gem. You’ve gotten an applause from me. ;)

Christopher James
Christopher James

February 15, 2024

Wow, Scott I didn’t realize! You’ve done some work here, isn’t that right? I went to browse through the site afterward because I only came across the article first then.. my ideas started materializing in front of my eyes! Ha We should connect, happy to volunteer to learn further and meet some folks. Background of sales and marketing. I’m actively breeding and crossing different Betta types now as well as practicing my shrimp colonies with neos (tap water here comes out around 240TDS and I haven’t worked out a better way yet). If there’s anything you feel I could bring to the table, please do not hesitate to reach out.


Christopher James
Christopher James

February 15, 2024

Such a great article, got back into the hobby summer of 22’ after a 15 year hiatus which stemmed from an attempt at a large reef (felt there was nothing else left unturned).. I’ve come back aboard and been in love with the botanical naturalistic style of planted freshwater and blackwater. Also, learning of the killi species for the first time in life. Like similar, pseudamagils, badis or Dario, our very own pygmy sunfish and like mentioned wild types of Betta or apistogramma morphs. Thinking of seeking out better ways to procure specimens of this species, I have a golden panchax but he’s like an assassin fish (I’m used to keeping larger cichlids of carnivorous nature but he is on his own level..) I’m interested in seeing peaceful interaction, maybe a species only colony trying annuals or lyre tail types. Would you guys have any recommendations for a east coast, united states fellow looking to get better into the loop of hobbyists actually keeping more of these killi types?


Ps. I’ve noticed a need for a lot of the naturalistic items and botanicals that no one shop looks prepared to fulfill for any of us. This may go hand in hand with my question above also and maybe I’m just unaware as of now. But I feel like an online retail operation is being called for all of the time with everything I’m seeing/reading. Something a little more friendly to the style that’s not Etsy but your superstore for specific biotope items, botanicals, specific rockery and driftwood.. delving into species specific specialty items. Maybe I’m wrong and as anything, it could fail miserably but I’d be willing to put my money where my mouth is.

Scott Fellman
Scott Fellman

February 08, 2020

Hi Charlie!

Glad you happened upon this piece! I think we have a better way- Check out our post from January 29th about the “Allure of ephemeral environments..” Perhaps a different twist on a way to keep annual killies! Like you, I adore these fishes and constantly ask if there is another way to keep them which can have mass appeal..I think keeping them in systems designed to highlight their habitats is a good starting point!

Best of luck!


charlie panella
charlie panella

February 05, 2020

Exactly the article Ive been looking for. Ive been an aquarist since childhood. Ive feared turning into an old kili guy with boxes of tiny fish in an unlit basement apologizing to anyone who comes in my fishroom for not seeing anything but tiny brown sticks…….. but its happening. Im getting the fever… help me there must be another way!!!!!!!!

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