Variations on a theme...experiments with Epiplatys annulatus and the idea of going beyond the ordinary...


I love killifishes.

Have you ever thought of keeping killifishes in a setting that is more similar to what they're found among in the wild? Now, I know that for controlled breeding, you'd typically want to keep them in small, bare tanks, with spawning mops, peat moss, or whatever the appropriate substrate is.

However, what about trying to simulate the habitats in which some are found? Would this work? Could you do it effectively? Would the fish reproduce?

Well, first off, I have no illusion that you'll be able to produce as many fishes as often as in a controlled, more "artificial"-type spawning setup. However, as one who is fascinated by how fishes interact with their environments, I couldn't help but wonder you could at least create an interesting, if not viable, setup to more realistically simulate the natural habitats from which these fishes come from. Oh, and I realize that we've been doing the "permanent setup" thing with killies for decades- you know, a small tank with a dense coverage of plants. That sort of thing. Now, that works, and may very well simulate the habitats of some killies, but many come from habitats which we generally don't replicate in aquariums. Habitats that lend themselves well to experiments on a very small scale!

Examples? Well, let's look at the tiny, but surprisingly popular Epiplatys annulatus Monroviae, "The Clown Killie." This little fish is commonly kept in the aforementioned permanent setups with a fair degreee of reproductive success. Of course, you can't argue with the success, but you can think about creating more natural conditions for these fishes to see if you'd get any different results, right?


Over the years, I chose this rather "touchy" species as my muse, along with the much easier to keep Epiplatys dageti Monroviae, as my killie of choice. I spent a lot of time studying the wild collection areas of these fishes, and came up with all sorts of ideas and theories about every aspect of them, ranging from why they have the colors they do, to what they really eat in the wild, to, what kind of water conditions to keep them in.

So, for the most part, these fishes are often found in very shallow jungle streams. How shallow? Well, reports I've seen have stated that they're as shallow as 2 inches (5.08cm). That's really shallow. Seriously shallow! And, quite frankly, I'd call that more of a "rivulet" than a stream! Virtually still, with a barely perceptible current. Now, I don't expect you to set up a tank that's 2 inches deep...but what about like 3.5"-4" (8.89-10.16cm) deep? Totally doable. There are some pretty small commercial aquariums that aren't much deeper than 8" (20.32cm), and you could adapt other containers for this purpose, right? Like storage boxes, etc. That's like "standard-issue" killie stuff.

However, we're not content to simply set up a 4-inch deep tank, throw in some killies and a clump of Water Sprite and call it a day, right? Nope. We need to do better. Let's think about this habitat again for a quick second.

As mentioned above, these little jungle streams are really shallow, cutting gently through accumulations of leaves and forest debris.  The great killie documenter/collector, Jorgen Scheel, precisely described the water conditions found in their habitat  as "...rather hot, shallow, usually stagnant & probably soft & acid." Ah-ah! We know this territory pretty well, right?

Oh, and here's a cool fact you may not have thought about...keep this in mind:  Because they also inhabit coastal areas (mine were the "Monroviae" population...) they are also found in slightly brackish water!

Hello. Yeah... And yes, I've exploited this interesting fact in the past, conducting a few experiments with this species as we'll see shortly- with really good results, too! And hopefully, you will too, in the near future, when we start releasing the Estuary line of stuff...but imagine, a botanical-influenced, brackish-water aquarium? For killies? Yeah. 

Ahh...back to the idea at hand....

How about a long, low aquarium, like the ADA "Cube Garden 60F", which has dimensions of 24"x12"x7" (60x30x18cm)? You would only fill this tank to a depth of around 5 inches ( 12.7cm) at the most.

Here is a pic of my experimental brackish water Epiplatys annulatus setup from a few years back. This one I actually filled to the top, used a fine layer of fine, white sand, and kept the water very slightly brackish (s.g.1.003). It was kind of an odd dichotomy, really, because I used some botanical items in the sort of "island" of rock I created in the lower light area on one side. You can guess where the fish spent most of their time! I incorporated what I now call "Mariposa Pods" a few little "Savu Pods", and some Coco Curls into the "island", which had a mix of terrestrial and true aquatic plants. Kind of a dichiotomy, because I had a "planted brackish botanical tank", with slightly tinted water!  Yeah, I've always liked pushing in different directions! 

The next question you'll ask is, "Did you have jumpers?" And my answer: "Nope." Was I lucky? Probably...but for 3 years.  Oh, and I had a thriving little reproductive population of these fish with little intervention other than maintenance.
And a thought on "touchy" fish in general? Yes, some fishes don't do as well in captivity as others. My theory? It's not that they are "weak fishes". It's because some fishes aren't handled correctly in the "chain of custody" from origin to aquarist. It's because we are not providing them with something that they need. Fish aren't touchy "just because they're touchy." It's usually because we don't provide them with a proper, consistent chemical environment (and don't just assume that what you read in the "aquarium literature" is the last word on the subject...), an appropriate diet that simulates their natural one, and a tank setup which replicates the physical environments from which they evolved to inhabit over eons. That's my theory, anyways!
Moving on...
I later experimented with these guys in a tank that was more reminiscent of the way many would create a "permanent setup" for them: Darker conditions, lots of plants, and soft, acid blackwater. A sort of "quasi-paludarium" setup, if you will.
This tank had dimensions of 12"x7"x9.5" (30x18x24cm), and was filled with a water depth (not counting substrate) of just  a hair under about 5 inches (12.7cm) again...Just couldn't break the 5-inch barrier for some reason!  Yet, I know it's entirely doable. Like many hobbyists, I've raised these fishes and other killies in plastic storage boxes with really shallow water depth. 
Although my experimental tanks were sort of "stylistically" crude, and not exactly in line with the way my aesthetic has evolved nowadays, they are at least examples of some alternatives to the more staid "permanent setup" that has historically worked for this rather touchy species. If I do this again (actually, when I do this again!), I will definitely go with a full leaf litter-covered bottom, a little "shoreline of marginal and terrestrial plants, and a bottom substrate of fine sand mixed with some soil. I will probably still do the brackish thing, because it was easy to do, and the fishes actually displayed better overall health and vigor (IMHO) in the "botanical/brackish" water conditions.
The key here was consistent water chemistry and quality, regular small water changes, good food (I used wingless fruit flies, baby brine shrimp, and small frozen bloodworms), and areas of lower lighting that the fish can retreat to (or, in my case, just hand out in 90% of the time!). Nothing too crazy, other than the brackish/botanical thing. And FYI, I very slowly acclimated my captive-bred specimens to these conditions. It was actually a bit arrogant to keep them under these conditions, because there are a variety of populations of this fish, and I had no way of knowing if the ancestors of mine came from these conditions...But hey, it was an experiment! 
Where am I going with this? Well, basically, I'm trying to convince you to dig a bit deeper when considering the fishes that you keep. Check out the many scholarly research papers you can find online about any number of seemingly arcane fish topics. If you persist, you can often unearth some real gems- useful pieces of information that can influence your decisions on how you'll keep various fishes. Stuff that, although perhaps contrary to "the way we always do it", can unlock other clues, secrets, and techniques, which may ultimately lead to greater success than we've seen before.
You've got the talent, the interest, and the access to all sorts of information that, only a decade ago, would have required you to write to museums and universities to retrieve... Now, you can find this stuff while sitting with your iPad in the chaise lounge on your patio!
It's a pretty cool time to be a fish geek! 
Stay excited. Stay curious. Stay innovative.
And Stay Wet.
Scott Fellman
Tannin Aquatics
PS- Sorry for the spacing issues on this blog...some sort of weird formatting issue with the blog software that I couldn't resolve... :(

Scott Fellman
Scott Fellman


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