June 05, 2021

From Nature's Idea Book: Floating leaf litter beds...

If you're a geek like me, you're always on the lookout for unusual ecological niches to recreate in your aquariums. And Nature doesn't disappoint! She's got a whole array of crazy-cool habitats which we as aquarists can appreciate and attempt to replicate in our tanks.

In places like the rain forest streams of Amazonia, biologists have observed floating leaf litter beds which hold together for quite a long time- almost becoming known "features" in the aquatic "topography" of the igarapes and streams of the region!

So imagine, if you will, a "classic" submerged leaf litter bed in Amazonia, composed of a variety of leaves, branches, twigs, seed pods, and other botanical materials...Yet, floating on the water surface; extending as much as a few feet under the water! What you get is a fairly deep layer of plant materials colonized by fishes and other creatures, which forage on the macro invertebrate life found in these complex assemblages.

Biologists call this an "ephemeral" habitat, as it is transitory or temporary as it slowly breaks apart-despite the fact that it might be years before this occurs.

Okay, so it slowly breaks apart over time.

This is cool.

And often, these floating or partially submerged leaf litter banks either accumulate among the branches of overhanging vegetation during the high-water season, gradually floating downstream, or they stay anchored in place by fallen tree trunks and other large materials, ultimately forming a more "traditional" submerged leaf litter bed as they sink.

Think about the possibilities to replicate these floating leaf litter beds in aquariums!

I found this to be an amazingly interesting niche! Reminds me of the Sargassum "forests" of the Caribbean and Tropical West Atlantic! Literal "floating feasts" for the animals which reside there! This is another potentially irresistible ecological niche for us to play with, right?

Oh- and many fish species associate with these floating litter banks for the entire wet season!

And one of the reasons they stay put is because their food sources are there, too! In fact, a species of "water bug", Weberiella rhomboides, is found almost exclusively in these floating banks, attracting large numbers of insectivorous fishes, like characins, catfishes, knife fishes, and others.

Yeah, it's a virtual "who's who" of blackwater, leaf-litter-zone dwellers, some of which are very familiar to us as hobbyists- for example, characins like Hemmigramus species, Moenkhausia species, the killifish Rivulus ornatus, and of course, cichlids, including a number of Apistogramma, Crenicichla, Hypselecara, and the much-loved Mesonauta festivus, to name a few. Can you imagine how this could make a very interesting theme for an aquarium?

Yeah, I can...as you'd imagine!

You'd want a fairly shallow, wide aquarium, and probably would filter it with an outside power filter or canister filter with the return positioned in such a way as to minimally disturb the surface. With minimal preparation (ie; cleaning them with a light boil, but not trying to saturate them to the point of the materials sinking right to the bottom), a lot of this stuff would sort of float for a while before sinking to the bottom.

You'd essentially be creating a diverse assemblage of botanicals, just like you would if you were doing a "conventional" leaf-litter display (I love that- I just called this stuff a "conventional leaf litter display"- look how far we've come...). And of course, Nature offers no shortage of inspiring leaf-litter habitats to examine!

Now, eventually, some of this stuff would sink, or be trapped below the floating "matrix", and you'd end up with materials on the bottom...okay...cool! It would transition naturally to a more "conventional" botanicals-on-the-bottom display. So this is essentially an "ephemeral display"- transitioning from a "floating leaf litter bed" to a submerged leaf-litter aquarium!

How freakin' cool is that?

Of course, you could probably keep it going by replacing the leaves and such as you would anyways, right? And as the wood becomes submerged, you'd "let it do it's thing", and/or replace/add new pieces.

A sort of actively-managed botanical-style tank...sort of like any other botanical-style tank- but with a twist...er, a float.

Stay creative. Stay inspired. Stay thoughtful. Stay observant. Stay diligent...

And Stay Wet.

Scott Fellman

Tannin Aquatics