Working the web....

There is a web of life out there, ready for us to embrace.

If you've followed us for any length of time, you're well aware that we are not just pushing you to play with natural, botanical-style aquariums only for the pretty aesthetics. We are almost as obsessed with the function of these aquariums and the wild habitats which they attempt to represent!

And one of the most important functions of many botanically-influenced wild habitats is the support of food webs. As we've discussed before in this blog, the leaf litter zones in tropical waters are home to a remarkable diversity of life, ranging from microbial to fungal, as well as crustaceans and insects...oh, and fishes, too!  These life forms are the basis of complex and dynamic food webs, which are one key to the productivity of these habitats. By researching, developing, and managing our own botanically-infleunced aquaria, particularly those with leaf litter beds, we may be on the cusp of finding new ways to create "nurseries" for the rearing of many fishes!

At least upon superficial examination, our aquarium leaf litter/botanical beds seem to function much like their wild counterparts, creating an extremely rich microhabitat within our aquariums. And initial reports form those of you who breed and rear fishes in your intentionally "botanically-stocked" aquariums are that you're seeing great color, more regularity in spawns, and higher survival rates from some species. We're just beginning here, bit the future is wild open for huge hobby-level contributions that can lead to some serious breakthroughs! 

Let's consider some of the types of food sources that our fishes might utilize in the wild habitats that we try so hard to replicate in our aquariums, and perhaps develop a greater appreciation for them when they appear in our tanks. Perhaps we will even attempt to foster and utilize them to our fishes' benefits in unique ways?

Maybe we will overcome generations of fear over detritus and fungi and biofilms- the life-forms which power the aquatic ecosystems we strive to duplicate in our aquariums. Maybe, rather than attempting to "erase" these thing which go against our Instagram-influenced aesthetics of how we think that Nature SHOULD look, we might want to meet Nature where she is and work with her. 

And we might see the real beauty- and benefits- of unedited Nature.

One of the important food resources in natural aquatic systems are what are known as macrophytes- aquatic plants which grow in and around the water, emerged, submerged, floating, etc. Not only do macrophytes contribute to the physical structure and spatial organization of the water bodies they inhabit, they are primary contributors to the overall biological stability of the habitat, conditioning the physical parameters of the water. Of course, anyone who keeps a planted aquarium could attest to that, right? 

One of the interesting things about macrophytes is that, although there are a lot of fishes which feed directly upon them, the plants themselves are perhaps most valuable as a microhabitat for algae, zooplankton, and other organisms which fishes feed on. Small aquatic crustaceans seek out the shelter of plants for both the food resources they provide (i.e.; zooplankton, diatoms) and for protection from predators (yeah, the fishes!).

I have personally set up a couple of systems recently to play with this idea- botanical-influenced planted aquariums, and have experimented with going extended periods of time without feeding my fishes who lived in these tanks- and they have remained as fat and happy as when they were added to the tanks...Something is there- literally!  

Perhaps most interesting to us blackwater/botanical-style aquarium people are epiphytes. These are organisms which grow on the surface of plants or other substrates and derive their nutrients from the surrounding environment. They are important in the nutrient cycling and uptake in both nature and the aquarium, adding to the biodiversity, and serving as an important food source for many species of fishes.

In the case of our aquatic habitats, like streams, ponds, and inundated forests, epiphytes are abundant, and many fishes will spend large amounts of time foraging the biocover on tree trunks, branches, leaves, and other botanical materials. Although most animals use leaves and tree branches for shelter and not directly as a food item, grazing on this epiphytic growth is very important. Some organisms, such as nematodes and chironomids ("Bloodworms!") will dig into the leaf structures and feed on the tissues themselves, as well as the fungi and bacteria found in and among them. These organisms, in turn, become part of the diet for many fishes.

And the resulting detritus produced by the "processed" and decomposing pant matter is considered by many aquatic ecologists to be an extremely significant food source for many fishes, especially in areas such as Amazonia and Southeast Asia, where the detritus is considered an essential factor in the food webs of these habitats. And of course, if you observe the behavior of many of your fishes in the aquarium, such as characins, cyprinids, Loricarids, and others, you'll see that in between feedings, they'll spend an awful lot of time picking at "stuff" on the bottom of the tank. In a botanical style aquarium, this is a pretty common occurrence, and I believe an important benefit of this type of system. 

I am of the opinion that a botanical-style aquarium, complete with its decomposing leaves and seed pods, can serve as a sort of "buffet" for many fishes- even those who's primary food sources are known to be things like insects and worms and such. Detritus and the organisms within it can provide an excellent supplemental food source for our fishes! Just like in Nature. 

It's well known that in many habitats, like inundated forests, etc., fishes will adjust their feeding strategies to utilize the available food sources at different times of the year, such as the "dry season", etc. And it's also known that many fish fry feed actively on bacteria and fungi in these habitats...so I suggest once again that a blackwater/botanical-style aquarium could be an excellent sort of "nursery" for many fish species! 

You'll often hear the term "periphyton" mentioned in a similar context, and I think that, for our purposes, we can essentially consider it in the same manner as we do "epiphytic matter." Periphyton is essentially a "catch all" term for a mixture of cyanobacteria, algae, various microbes, and of course- detritus, which is found attached or in extremely close proximity to various submerged surfaces. Again, fishes will graze on this stuff constantly.

And then, of course, there's the "allochthonous input" that we've talked about so much here: Foods from the surrounding environment, such as flowers, fruits, terrestrial insects, etc. These are extremely important foods for many fish species that live in these habitats. We mimic this process when we feed our fishes prepared foods, as stuff literally "rains from the sky!" Now, I think that what we feed to our fishes directly in this fashion is equally as important as how it's fed.

I'd like to see much more experimentation with foods like ants, fruit flies, and other winged insects. Of course, I can hear the protests already: "Not in MY house, Fellman!" I get it. I mean, who wants a plague of winged insects getting loose in their suburban home because of some aquarium feeding experiment gone awry, right?

That being said, I would encourage some experimentation with ants and the already fairly common wingless fruit flies. Can you imagine one day recommending an "Ant Farm" as a piece of essential aquarium food culturing equipment? Why not right?

As many of you may recall, I've often been amused by the panic that many non-botanical-style-aquarium-loving hobbyists express when a new piece of driftwood is submerged in the aquarium, often resulting in an accumulation of fungi, algal growth and biofilm. I realize this stuff looks pretty shitty to many of us, particularly when we are trying to set up a super-cool, high-concept aquascaped tank.

That being said, I think we need to let ourselves embrace this. I think that those of us who maintain blackwater. botanical-style aquariums have made the "mental shift" to understand, accept, and even appreciate the appearance of this stuff. Natural habitats are absolutely filled with this stuff...it's like the whole game here- an explosion of life-giving materials, free for the taking...

Another "mental shift", I suppose...one which many of you have already made, no doubt. I certainly look forward to seeing many examples of us utilizing "what we've got" to the advantage of our fishes! AGAIN: A truly "Natural" aquarium is not sterile. It encourages the accumulation of organic materials and other nutrients- not in excess, of course. Biofilms, fungi, algae...detritus...all have their place in the aquarium. Not as an excuse for lousy or lazy husbandry- no- but as supplemental food sources to power the life in our tanks.

Real gifts from Nature...that you can benefit from simply by "working the web" of life which arises without our intervention as soon as leaves, wood, and water mix.

Keep making those mental shifts. Meet Nature where it is.

Stay bold. Stay inquisitive. Stay open-minded. Stay grateful. Stay diligent...

And Stay Wet.

 

Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman

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1 Response

Scott Gale
Scott Gale

May 27, 2019

I had a rock holding down a few leaves, yes, I just rinsed them off and popped them in…shame on me! Yesterday during my water change, I moved the rock because the leaves were saturated enough to stay down. Within an hour, a big group of Cherry Shrimp had moved onto the spot and grazed there all night. Maybe because that spot was covered for a couple weeks, it had extra time to develop the microorganisms the shrimp like to eat? I’ll have to try it again sometime.

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