June 04, 2019

Palms in the water...opportunities in abundance. Consider the "morichal" habitat.

As lovers of the natural, botanical-style aquarium, it's always fun to study habitats where fishes come from and see how we can replicate aspects of them in our aquariums. In fact, it's like the whole game, right? Nature has created so many interesting habitats in which life can flourish.

One thing that we find amazing about the natural world is that there seems to be an inspiring habitat for just about everything out there. In the seemingly endless search for new aquarium ideas, we spend a lot of time looking for new ideas- new ecological niches to simulate, to stretch your creativity a bit.

We've spent some time over the past couple of years studying an aquatic environment that you might not have thought much about before, yet is just begging for you to replicate in the aquarium!

Enter the "morichal..."

Oaky, cool Scott. What's a "morichal?"

Hmm...glad you asked.

A "morichal" is a lowland stream found in Savannah areas of South America, Amazon River basin, the upper Negro River drainage in Brazil, the Orinoco River basin, and along the Orinoco River in Colombia and Venezuela, among other locales. The habitat is dominated by a certain type of palm tree, the "Moriche Palm" (Mauritia flexousa), and extensive riparium vegetation. This palm only grows were its roots can be underwate (love that!), and typically is found in groups- hence the term, "morichal", which refers to...a group of them!

Morichals are considered important systems for the maintenance of freshwater Neotropical fauna in lowland savannas. The monodominant stands of the palm and associated growths provide important food to a great number of species,

Although typically supplied with underground water sources throughout the year, these streams swell with water during periods of seasonal flooding. Riparian vegetation and sandy substrates abound. And when you have trees, vegetation, and seasonal influx of water, utilizing botanicals in your aquarium replication of this habitat is just "par for the course', right?

The habitat itself has an abundance of botanical debris, leaves, macro algae, fallen branches, palm fronds, and a matrix of roots and such. And, with terrestrial plants growing right up to the water's edge, the possibilities to create a cool aquatic display are unlimited! With a little creativity, one could simulate the growth of the riparian vegetation of the "morichal."

I've cultivated some riparian plants, such as Acorus, for the past couple of years, which "I'm gonna" use someday in a paludarium-type replication of this habitat! A paludarium would open up some unique aesthetic opportunities to really push the boundaries of creativity!

In the past, Ive even experimented with small "Cat Palms" (Chamaedorea cataractarum) and rooted them in leaf-strewn, shallow sand substrates- a sort of "micro morichal" setup! I know this concept can work! Further experimentation in this area can no doubt yield some cool results!

And of course, whenever you have these complex physical habitats, you end up with a diversity of life and food sources- and hence, fishes which are suited to exploit them. This interesting summary from a study I encountered on Morichal habitats expands upon this:

"In structurally complex habitats, specialist species also can exploit specific food resources to which they are morphologically or physiologically adapted to utilize (Willis et al., 2005). For example, in vegetated patches we found a relatively high abundance of small cichlids and doradid catfishes with different body shapes and feeding habits (e. g., Apistgramma hoignei, Physopyxis ananas). But small omnivorous characids with less-diversified body morphologies (Characidae), such as tetras of the genera Moenkhausia spp. and Hemigrammus spp., dominated open and shallow beaches.

Littoral habitats containing woody debris and leaf litter also might support higher primary and secondary productivity which provides fishes with more foraging opportunities on a larger variety of substrates (Benke et al., 1985; Crook & Robertson, 1999). Relationships between fish structure and macroinvertebrate assemblages have been associated with habitat heterogeneity (Angermeier & Karr, 1984)."

Although the waters in these habitats are largely clear (as in, not turbid), they are stained with tannins and are typically acidic in pH (usually 6.0 or less), and have a significant amount of roots and such from the terrestrial and riparium vegetation surrounding. You'll find lots of palm leaves, fruits, and seed pods submerged on the substrate in morichals.

And of course, that's where we come in, right?

What would be good botanicals to utilize in an aquarium representing this habitat?Well, some of our palm-derived selections would be a good start! Since palms are an important part of this habitat, it would only make sense that these materials form an important part of your aquascape, right?

Scattering these materials along the bottom of the aquarium would create a pretty good replication of the morichal environment! I would probably not go too crazy, in terms of variety; rather, I'd limit my selections to a few of the above and just sort of "do it up" that way, so as to emphasize the abundance of several dominating plant species in the locale.

Although not as productive as the Amazon River itself, these environments often contain dozens of different fish species in relatively small areas, including characins, catfishes, and dwarf cichlids. Unusual characin species, such as Hemiodus, are often found in these habitats. Occasionally available in the aquarium trade, they would make really cool "stars" for a specialized display like this! The lovely "Green Neon Tetra" (Paracheirodon simulans), is a known (and super sexy!) denizen of this habitat, as well!

Oh, and Dwarf Pike Cichlids are often found in morichal habitats...hello!

Of course, some of the more popular characins, such as Pencilfishes (N. unifasciatus is notable), are found there. And Apistogramma, along with the beloved Mesonauta insignis, are found in morichals, which will lend a familiar, if not somewhat exotic look to your display!

As a subject for a riparium study, the morichal environment presents a near-perfect opportunity to stretch your aquatic creativity, while highlighting some well-known fishes in an unusual and not-often-replicated niche.

Think of the creative possibilities here!

The abundance of botanicals and wood available to us today makes it easier than ever to realistically replicate this habitat! There are numerous amazing materials which you can employ to replicate the functional and aesthetic aspects.

The morichal is symbolic of where we are in the aquarium hobby: At a real "high point", where it's entirely possible to create realistic, "functionally aesthetic" aquatic display utilizing natural materials to mimic the look and feel of the amazing aquatic habitats of the world, while simultaneously learning about these priceless natural treasures.

Where to next?

Learn a little. Get excited. Have fun. Fly in the face of convention.

Stay studious. Stay fascinated. Stay innovative. Stay creative. Stay inspired...

And Stay Wet!

Scott Fellman

Tannin Aquatics