June 01, 2020

To the roots...

I spend a tremendous amount of time focusing on specific habitats and ideas to recreate them in the aquarium, and few have proven as popular- or alluring- as the flooded forest floors of Amazonia. We've visited these habitats multiple times in our blog, and done some discussion on the fishes and animals which reside in them during the periods of inundation (which is usually around September to the end of May).

When the forests flood, the sandy soils are carpeted in aggregations of botanical detritus, root tangles, fallen logs, leaves, bark, etc. from the formerly dry forest floor. This is, of course, the stuff we as botanical-style blackwater aquarium enthusiasts are most interested in. One of the key components of this habitat, from a "structural/spatial" sense, is the presence of logs, branches, and roots from fallen trees.

Yes, roots.

We see many aquariums which feature wood and leaves, of course. However, I think we don't see a tremendous use of smaller branches, roots, and "twig-sized" pieces, and I think that is something we would definitely like to see more of in our aquariums. There is something remarkably realistic about the presence of these smaller materials in an aquarium. The complexity and additional "microhabitats" they create are compelling and interesting. And they are very useful for shelling baby fishes, breeding Apistogramma, Poecilocharax, catfishes, Dicosssus, an other small, shy fishes which are common in these habitats.

Now, small root bundles and twigs are not traditionally items you can find at the local fish store or online. I mean, you can, but there hasn't been a huge amount of demand for them in the aquascaping world lately...although my 'scape scene contacts tell me that twigs are becoming more and more popular with serious aquascapers for "detailed work"...so this bodes well for those of us with less artistic, more functional intentions!

In flooded forests, roots are generally found in the very top layers of the soil, where the most minerals are. In fact, in some areas, studies indicated that as much as 99% of the root mass in these habitats was in the top 20cm of substrate! Low nutrient availability in the Amazonian forests is partially the reason for this. So, ecological reasons aside, what are some things we as hobbyists can take away from this?

Well, for one thing, you can use a lot of materials to create a very dense look of tangled root structures extending into the water. For example, Melastoma roots have a perfect, delicate structure, and when combined with smaller wood pieces of materials like "Spider Wood", "Tangle Wood Root", or even "Tiger Wood" from our collection, create a very unique, realistic look.

Although we are out of Melastoma roots at the moment, we are expecting a large, long-delayed shipment (Thanks, coronavirus) of them later this month! The nice thing about a tangled mix of roots is that it not only creates a unique aesthetic- it creates a fascinating natural foraging area for fishes.

Okay, "infomercial" time over.

Fungal growth, biofilms, and small crustaceans/microorganisms will live in the tangled matrix of small roots with enormous surface area. This has the dual advantage of functioning not only as a producer of supplemental food sources, but as a natural nutrient processing "facility" in the aquarium. This is a huge and important benefit provided by this type of assemblage.

In Nature, these assemblages also serve a similar role, and "sequester" materials like leaves and such, further adding value to the resident life forms. These areas are ideal for fishes to use for spawning sites and shelter from predators, as well.

The trees-or their parts- literally bring new life to the waters which surround them.

The materials that comprise the tree are known in ecology as "allochthonous material"- something imported into an ecosystem from outside of it. (extra points if you can pronounce the word on the first try...) And of course, in the case of trees, this also includes includes leaves, fruits and seed pods that fall or are washed into the water along with the branches and trunks that topple into the stream.

These materials are known to ecologists as “coarse particulate organic matter”, and in the waters of these inundated forest floors there is a lot of CPOM, and the community of aquatic organisms (typically the aforementioned aquatic insects and crustaceans) has a high proportion of “shredders”, which feed on the CPOM and break it up into tinier bits called (wait for it...) "fine particulate organic matter."

Some of these "shredders" and their larvae are a direct source of food for fishes, providing a nutritious food source for growing populations in these waters.

And of course, some fishes directly consume fallen fruits and seeds themselves as part of their diet as well, aiding in the "refinement" of the CPOM. Think about the Pacu, for example, which has specialized mouthparts suited to crushing hard-shelled fruits and seeds. Other organisms make use of the fine particulate matter by filtering it from the water or accessing it in the sediments that result. These allochthonous materials support a diverse food chain that's almost entirely based on our old friend, detritus!

Yes, detritus. Sworn enemy of the traditional aquarium hobby...misunderstood bearer of life to the aquatic habitat. Just another benefit (yeah, you heard me right) to recreate these complex "root tangles" in the aquarium.

I have this obsession with these little niches in wild habitats, where a confluence of materials occurs. There IS something fascinating about tangled roots, branches, submerged, decaying vegetation, and rich substrate intersecting in the wild that has inspired me to replicate aspects of them in my aquariums in recent years.

We talk a lot about "microhabitats" in Nature; little areas of tropical habitats where unique physical, environmental and biological characteristics converge based on a set of factors found in the locale. Factors which determine not only how they look, but how they function, as well.

As aquarists, observing, studying, and understanding the specifics of microhabitats is a fascinating and compelling part of the hobby, because it can give us inspiration to replicate the form and function of them in our tanks! Just looking closely at an image of one of these locales can give you a plethora of tank ideas!

Continue to look to Nature for your inspiration. Make the effort study the way life forms adapt to these habitats and live within it. The lessons we can learn are so numerous, and so potentially beneficial, that we simply can't overlook this niche.

Get back to the roots! Literally!

Stay bold. Stay curious. Stay creative. Stay excited. Stay observant...

And Stay Wet.

Scott Fellman

Tannin Aquatics