Homage to a fave friend...

It's hard to believe that it's been more than four years since we've started operations here at Tannin Aquatics. And more incredible to consider how, during that time, the idea of botanical-style aquariums (blackwater, brackish, or otherwise) has slowly percolated into the mainstream of hobby consciousness- leaving behind the hushed "side show" feel that the concept used to be met with.

Now, I don't claim that we were the main "mover" of this shift, but I think we've had some impact on it. In fact, the term "botanical" used to describe the natural stuff we work with, placed in our aquariums was simply not used in this context prior to 2015, to the best of my knowledge. 

Of course, I'm not saying that hobbyists haven't been tossing in leaves and seed pods and such prior to our arrival on the scene. That would be arrogant, egotistical, and just wrong. Hobbyists have been tossing "stuff" into aquariums pretty much as long as there have been aquariums!

That being said, there really wasn't a sort of "nexus" for the study, application, and procurement of this stuff before we arrived, as far as I know.

And since we've been researching, curating, and offering this stuff here at Tannin, I'd like to think that we've helped advance the identification, preparation, and application of these natural materials in our aquariums. It's more than just selling this stuff- it's about helping foster a "movement" which advances and educates the aquarium hobby. And it starts with some really basic stuff.

When I first started experimenting with tossing leaves, seed pods, and the like into aquarium over a decade ago, one of the main things I used as my criteria for evaluating the suitability of a botanical for aquarium use was what I call "functional aesthetics."

Really just a buzzword-like way of saying that I like stuff to look cool and be useful as well!

And, when it comes to the concept of "functional aesthetics", you'd be hard-pressed to find a botanical which meets this definition as much as what is debatably our most popular botanical- the Cariniana pod.

It's the seed pod of the Cariniana legalis tree from the forests of Brazil. With its unique cylindrical shape and nice opening on one end, it's a near-perfect "botanical accent piece" for all sorts of aquatic and vivarium applications.

I mean, it checks all the boxes: It looks cool, it's durable, and has that cool "defensible opening" that fishes or frogs can hide in and use as a hangout or spawning cave.  And it''s easy to prep for aquarium use, too!

Yet, it's been given a whole lot of f-ing stupid names, and has been sort of misunderstood for a long time. So, we'll just revisit it once again...

What's the real story on this pod?

Well, it's back to the rain forests of Brazil.

The origin of this botanical is the Cariniana legalis tree- one of Brazil's oldest trees, with some specimens over 3,000 years old! Can you imagine how many of these pods such a tree can produce over its lifetime? 

(Damn, I'm such an exploitative capitalist...Shame.)

(Our fave tree in all its jungle glory! Image by mauroguanandi, used under CC BY 2.0)

This woody tree from the family Lecythidaceae is an impressive tree which rises majestically above the rain forest canopy. Scientist describe this tree as "A large emergent tree, sparsely scattered in areas of lowland non-flooded rainforest, such as Atlantic forest, mesophyllous, riverine or hygrophyllous forest and semi-deciduous woodland."

Couldn't have put it better, myself. Really. 😆

Now, the bad news about this species is that it is considered "vulnerable" by the The IUCN Red List of Threatened Species, as its habitat is under threat.  We obtain our specimens from a producer who has plantation-grown trees, which are specifically maintained for this and other human purposes, without chopping them down or destroying surrounding lands. 

In some areas, the bark and leaves are used for medicinal purposes (supposedly it has anti-diarrheal properties) and for binding stuff. We, of course, love the seed pods! I'll just take the word of the indigenous people that it's good as a diarrhea remedy...

Now, what we call a "pod" is really what a botanist would call a "dehiscent pyxidia"- a really cool, tongue-twisting way of saying that it's a fruit capsule, from which the upper part falls off when the seeds are released! Yeah, why couldn't they just say it THAT way, right?

Botanists, sheesh.


Funny side story: When I first started to obtain this pod, my supplier from South America would send many that were completely intact, with the upper part of the fruit capsule sealed...and more-or-less "welded" shut. So, essentially, everything which made the pod useful to us as fish geeks (ie; the opening and hollow interior) was not there...I still have a bag or two of hundreds of these things that I've not been able to use...I was like, "What?"

Hmm, maybe I can harvest the seeds and try to grow my own, lol...

So, there was bit of a learning curve with this stuff for me!

And then there was that damn name...The "Savu Pod."

Stupid. Urghhhh!😫

And I was stupid for calling it that, too.

I took the "advice" from a friend of a friend, who was into frogs, who told me rather authoritatively when I started playing with these and told him about them, "That's what they're called." And of course, I stupidly used it, too. And the reality probably is, that's what some hobbyist somewhere called them, and the name stuck.

And yeah, I contributed to this nonsense... I was an idiot. 

"Savu Pod", catchy though it might be- is a made up name, with no meaning whatsoever to science, or the locals in Brazil, where it's known as  "Jequitiba-branco", which refers to the fruit of the tree. In fact, if you must know... The Tupí name "Jequitibá" consists of the word jiqui(e) meaning "bow net" and the word "yba" which is "fruit tree" or "fruit."

No mention of the freaking name "Savu" anywhere. "Cause it's made up and completely irrelevant...sounds "exotic", but has no relation to the botanical itself at all.  Stupid.............

Yeah, I'm killing this name forever, as far as we're concerned. Good f---ing riddance.😆

If you must know- like I must:

"Savu" (also known as "Sawu", "Sabu", "Sawoe", "Havu", "Hawu",  or "Hawoe") is the largest of a group of three islands, situated midway between Sumba and Timor in Indonesia...like thousands and thousands of miles west of where this tree is ever found. Like, WTF does this have to do with this pod?


Stomp it out of your language forever. I will never refer to these botanicals by "that name" again. Ever. Except to mock those who do use it.. 😆

This is why I am so stupidly angry about the coral part of our hobby...Stupid names...grrr... Don't start me here.

Okay, that felt good. Really angry- perhaps a bit over the top- but- like, really good!

Deep breath, Fellman.

So, back to the botanical itself.

We will always refer to it as the Cariniana pod, 'cause that's what it is. It's simple and descriptive enough, without being as goddam lame as "Savu Pod."  It works for me...And besides, calling it "The Cariniana dehiscent pyxidiawould just be a bitch to spell, right?

Wow, I just couldn't let the whole name thing go, huh?


To prepare the Cariniana Pod for use is pretty straightforward. 

Annoyingly, they'll float like mad when introduced to water, but their buoyancy tendencies can be conquered relatively easily. You'll simply need to boil them, like many other pods we work with.

Place them in an inert pot, fill with fresh water, and bring them to a boil. Keep poking at them during the process to make sure they get submerged as much as possible during boiling. Once the water reaches a boil, reduce heat and let them do their thing for at least 20-25 minutes. Allow them to cool, then place them in a container of fresh, room temperature water to make sure that they've been "sunk."

Sure, sometimes it will take much longer...or a lot of extra soaking- to get them to really stay down. This is the price we pay for working with natural materials...There is no "guarantee" that says this stuff will sink in an hour.

We just have to  be patient! 

Like pretty much any "woody" botanical item out there, these pods will leach small amounts of tannins, lignin, and likely other compounds and organics for a while after you boil them.  Not enough to create dark brown water, but there is some leaching, regardless.

Traditionally, we've recommended to soak these for a day or two in a container of fresh water, to assure that they are fully saturated and have the chance to leach out the bulk of the initial bound up dirt, etc. after boiling. Quite honestly, I've usually skipped the extra "post boil soak" of late, without any issues, but it's your call.

And they are absolutely useful pods.

Fishes like Apistos will take to them easily, utilizing their cavity as a place to rear and protect their clutches of fry, much as they would exploit such a submerged seed pod in Nature. I Know that some hobbyists worry about fishes getting trapped in the opening. I've never had this happen, myself...so I don't stress out about it.

Now, we know that these are from trees found in rain forests of the Amazon region. We know that these forest floors flood seasonally, and are often inhabited by hundreds of species of fishes, which feed off of the allochthonous input from the surrounding terrestrial vegetation. It begs the question: Are Cariniana pods found on flooded forest floors, and utilized by fishes in ways like they are in the aquarium?

I can't say with 100% certainty, but it seems like a possibility. So these could be one of the most "authentic" botanicals we offer- perhaps filling the same exact "role" in our tanks as they do in their wild habitat. 

I'm probably getting to worked up or too contemplative about this stuff...

Regardless..these cool botanicals provide form, function, and aesthetics in one neat package...

And that's something that I think we can all get worked up about!

We just need to continue to NOT use that "other" stupid name for them, okay?


Until next time...

Stay relentless. Stay curious. Stay diligent. Stay creative. Stay patient...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

Scott Fellman
Scott Fellman


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