Recently, it seems like we have had a "rash" of spawning of characins in our tanks that have historically proven to be somewhat challenging (at least, for us!). First, it was the Pencilfish Nannostomus beckfordi, with a spontaneous and seemingly out-of-the-blue spawning event one evening last week.
The fish had been eating ravenously, coloring up dramatically, and "sparring" was occurring between what were obviously rival males for the first time in the many months since I obtained the fish. In the back of my mind, I was thinking to myself, "At some point, these guys are gonna spawn..."
Well, they did, but the "at some point" came a lot sooner than I expected!
Several days back, it was my Rummynose Tetras (Hemigrammus bleheri), which provided an unexpected treat one evening.
Wow, two fishes that I have deliberately attempted to spawn over the years without success, and they spontaneously engaged in this behavior on their own. What was I doing differently this time?
Well, obviously, the most obvious thing was that the fishes live in an environment that is much more reminiscent of the ones from which they came. That is to say, soft, acidic water, richly stained with humic and tannic acids from driftwood, leaves, and some seed pods on the substrate.
As an obsessive water change fan, I am devotedly changing 10 gallons of water weekly from their 50-gallon aquarium, with water conditioned in a similar manner as that in the display tank (i.e.; soft, acid water and influence of botanical-derived tannins). Their environment is nothing if not consistent.
It would be easy for me to give all the credit to the botanicals...I mean, offering them is what I do for a living, so I could hardly be blamed for making that claim...but I think it would be incomplete, at best.
The reality is, I am providing my fishes with a stable chemical environment, consistent with the conditions that these wild fishes came from. I'm keeping dissolved organics in the water to a minimum by using chemical filtration (activated carbon, Poly Filter, and Purigen) on a continuous basis and conducing the aforementioned water changes like clockwork. The fishes are feed extremely high quality food daily, and I take the time to make sure each one gets his or her fair share.
In short, I'm doing nothing differently than any other hobbyist who has ever bred fishes has done. The only different thing is that I am not providing these conditions for the expressed benefit of spawning the fishes.
The fishes are simply doing what comes natural. They're reacting to proper environment and nutritional parameters. If they had slightly different requirements, these spawnings would likely not have taken place. This happy result is simply the combination of selecting fishes carefully for the environment that was prepared for them and consistent husbandry. If's not "rocket science" by any stretch.
I profess, as I have for many years, that it's practically inevitable that animals will reproduce- or attempt to reproduce- when presented with environmental conditions that are appropriate for them. The "skill" part for the hobbyist comes in when we do what it takes to analyze, select, and provide these conditions for our fishes. Oh, and include a healthy dose of patience.
As a reef aquarium enthusiast, I often reflected on this when a reef tank was "cranking", with corals growing, and fishes like Clownfish spawning regularly. I knew that other fishes, like bennies, gobies, etc. would be "doing there thing" as well- and they were-when conditions were right-in my reef, and in thousands of other hobbyist's reef tank around the world. It was less about my brilliance as an aquarist than it was about my making the wise choice to engage in practices that offered optimum conditions for my animals.
The aquatic botanical thing? Well, yeah, it makes sense that fishes from an environment with soft, acid water rich in humic acids and tannins would spawn in an aquarium which had a diverse and significant assemblage of materials that provide these substances. In decades past, it would have been the same if I used peat moss in my filters and conducted the same water changes, etc. So yeah, credit to the botanicals for "doing their thing", but an equal part could be given to consistent, traditional methods of husbandry.
In short, if you find yourself stuck, wondering why you can't get those stubborn fishes to breed...Do the obvious: research where they came from in nature, attempt as closely as possible to recreate those conditions, and engage in consistent, fundamental husbandry technique, and the result is almost a forgone conclusion. of course, getting the fishes to spawn is one thing. Collecting the eggs, rearing the fry, etc., is quite another. That requires an additional skill set, patience, and time, which not everyone can provide on the first- or even the fifth-try. The procedures are a bit more complex, less forgiving, and more labor-intensive.
So why not make the "easy" part of the equation, well...easy, and at least focus on providing your fishes-even if they're just in a display- with the conditions they would need if you were attempting to spawn them intentionally? It's one of those "no-brainer" things in fish keeping that should be immediately obvious, but we tend to overlook in our busy, daily lives and the many other commitments besides our aquariums that fill them.
Give this idea a shot. The results just might surprise you.
Then again, maybe they won't.
Stay curious. Stay excited. Stay consistent.
And Stay Wet.