As aquarists, we spend a good part of our time trying to figure out how to keep our fishes healthy and happy. And as dedicated natural aquarium enthusiasts, we take it a level deeper, and try to re-create as many of the features of our fishes' natural habitats as possible.
And I think it goes beyond just creating a cool-looking habitat with wood or botanicals or rock, and calls upon us to investigate other factors, such as the currents and underwater topographic features of these ecosystems. There is a reason why fishes aggregate and live out their lives in specific environmental niches; and it goes beyond just the presence of leaves, or the acidity or alkalinity of the water.
The physical structures and flow patterns which make up the streams, rivers, and other aquatic habitats are a fascinating study in and of themselves.
I'm fascinated by "rifﬂes' (defined as shallow sections of a stream with rapid current and a surface broken by gravel, rubble or boulders), with a moderately-fast-ﬂowing current and mostly sandy bottom with tree roots, leaves, driftwood pieces, and small rocks and pebbles. (ohh...home to Darter Characins! I'm thinking cool niche biotope aquarium here...)
These "riffles" are considerably more significant in the wet season, when the obvious impact of higher water volumes are present. They're fascinating habitats to explore- and interesting to replicate in our aquariums!
And interestingly, in South America, you'll find an unexpected abundance of some species familiar to us as hobbyists in these "riffles." Species like Pyrrhulina brevis, Hyphessobrycon melazonatus, and Hemigrammus of various forms, and even some Nanostimus, and the killie Rivulus compressus! I find this intriguing, because we tend to associate a lot of these little fishes with sluggish water and more static environments, not areas exposed to greater current and movement.
I pose the question once again:
Interesting "factoid": Some scientists have postulated that the higher presence of nocturnal predators in the pools adjacent to the more active riffles might increase the number of species that seek refuge in the riffles to avoid them!
So, protection from predators- survival- is a powerful motivation for fishes to seek out these different habitats. Now, granted, in the aquarium we are almost guaranteed NOT to keep predators and prey in the same tank (at least, not for long-term display purposes!), but is there not something to be gained by replicating such environments?
Reduction of stress. Fostering of natural behaviors...Even if they are not "necessary" for survival. I can't hope but wonder if providing some of these more specific environmental conditions (in concert with stuff like water chemistry and the presence of stuff like leaves, wood, etc.) could facilitate greater possibilities for spawning, long-term health, and greater lifespan?
Application of water movement-something we've embraced in reef aquariums for decades to facilitate natural responses and long-term health in our animals- has its place in almost every type of natural aquarium, doesn't it?
So, dust off those powerheads. Reconsider the way you return water to your aquarium. Evaluate the underwater topography of the natural environments and the life habits of your fishes from these locales.
Further, re-think stuff like lighting patterns, rain, etc., and their influence on our fishes. Consider how we might apply this information to better the lives of the fishes in our aquariums.
Dive deeper. Consider the "complete package" the next time you set up an aquarium. You might just find that you're pushing the needle on the state of the art of the aquarium hobby a bit farther, right?
I think so.
Stay creative. Stay motivated. Stay fascinated. Stay resourceful. Stay observant...
And Stay Wet.