Jumping' into Jackfruit leaves!

As a long-time practitioner of the the botanical-style, blackwater aquarium, I've devoted many years to studying sourcing, and utilizing all sorts of botanical materials for use in my tanks. Sometimes, it hits me how incredibly geeked-out I am about the idea of playing with leaves and stuff.

I admit, it makes me smile when I realize that I've brought a level of geekiness to something as esoteric as "twigs, nuts, and 'dirty water' aquariums" (as one of my reefing buddies gleefully pointed out) for my fellow hobbyists to enjoy. It's satisfying to have built a business based on this weird obsession!

I mean, I can talk for hours about this stuff!

As you know, it's kind of an ongoing mission of ours here at Tannin Aquatics to seek out, research, and experiment with all sorts of botanical materials and leaves in our aquariums.  (Damn, that sounded very" Star Trek" of me, huh?) Over the first several years of our existence, we've been privileged to have access to a variety of botanical materials which have not previously been used in aquariums. 

Every one in a while, I have to highlight some of my favorite botanicals- not out of some self-serving desire to push what's "hot", or not selling, or whatever...Rather, to celebrate, elevate, and share my love of some of them with you, "Tint Nation", because they're so damn cool!

And because, as my wife says...I'm a geek.

So be it. :)

And of course, you're no doubt shocked to hear that the botanical we're talking about today happens to be a leaf. ("WTF is it with leaves and Fellman?")

When it comes to leaves for aquarium use, I have tried quite a few types over the years, and one of my faves has to be the leaves of the Jackfruit tree (Artocarpus heterophyllus).  It's one we've offered for some time now, and it's always been sort of the forgotten stepchild of the more popular leaves we offer, which don't seem to get the level of love and devotion as Catappa and Guava, so I thought I'd share my love for them with you today!

Now, this tree is very common in some parts of the tropical world, such as Southeast Asia and India, and the fruit and leaves have been utilized as a food and used in traditional medicines for centuries. They are particularly abundant in India, and that's where our experience with them began. Jackfruit trees are often found overhanging rivers in India, dropping leaves into the water, and of course, imparting a brownish tint as they decompose! SO, right from the start, here's a leaf doing in Nature what we want it to do in our aquariums.


Not surprisingly, Jackfruit leaves have been used by fish geeks in India to impart tannins into their aquarium water, much in the way Catappa, Guava, or other leaves are. A friend of ours, author/photographer/awesome fish breeder, Sumer Tiwari, told us they worked great with his killies and Dwarf Cichlids! And if you've seen his award-winning fishes, you'd give this a lot of thought and listen to the guy!

As a lover of botanicals, and leaves in particular, I was immediately interested, of course, and was able to lock down a terrific source for these unusual leaves, and began playing with them in my own tanks! Dutifully impressed with the results, we released them for sale to you, where they have become a "regular" in our lineup of botanical goodness!

And to our knowledge, at the time (around 2015) they hadn't really been that available regularly outside of their native regions for aquarium use before, and we were, of course, thrilled to be able to offer them to hobbyists!

Now, like all sorts of botanical materials we work with, Jackfruit and its leaves do contain compounds which are known by science to be beneficial for human health. 

It's long been documented by nutritional scientists that Jackfruit itself contains phytonutrients, such as lignans, isoflavones, and saponins, that have health benefits that are wide-ranging for humans. (Notice I'm emphasizing the "human" part yet again here?). Too many aquatics vendors are too quick to ascribe every human-related benefit from botanicals to fishes or shrimps, and I think that's kind of "reaching" a bit. I mean, sure, some of these things likely do "translate" to fishes, but I think it's a bit irresponsible to state absolutely that this is the case...

There is some conflicting data regarding jackfruit's antifungal activity. However, the leaves may exhibit a broad spectrum of antibacterial activity. In traditional medicine, these leaves are used to help heal wounds as well. Now, this is sort of similar to the attributes ascribed to Catappa, and there is probably a lot of "wiggle room", in terms of what they really can do and what we'd like them to do!

And, as we've said before- what some of these materials can do for humans, they may not necessarily do for fishes.

That being said, there are some things that we are aware of- mainly that they are durable, attractive leaves, which definitely can impart tannins into the water, giving it a nice tint! As mentioned above, we are not aware of any scientific studies that have been completed to correlate "medicinal" or "prophylactic" benefits of Jackfruit leaves specifically- to fishes or shrimps, one way or another- so for now, we're content to utilize these leaves for their aesthetics, biofilm "recruitment", durability, and proven ability to impart a tannin "tint" into aquarium water!

We do know that many of the chemical compounds contained in the leaves, as outlined above, are similar to those contained in Catappa leaves, and studies done on Catappa leaves do indicate some potentially anti-fungal properties in fishes...so... yeah.

From an aesthetic standpoint, these are nicely-shaped, high quality leaves that bring a very nice "tropical" aesthetic to the aquarium, as well as that tint we love so much around here! Jackfruit leaves look amazing as part of a mixed leaf litter bed, and are "strong enough" aesthetically to stand on its own, too! 

They will last a pretty long time- not quite as long as say, Magnolia, Mangrove, or Live Oak, but much longer than Catappa and Guava, in our experience.  And they hold their shape really nicely, sink rapidly after minimal prep, and stay down- all prerequisites for successful deployment underwater in an aquarium!

They will recruit biofilms on their surfaces, which, as most of you know, shrimp love to feed on (as well as consuming the leaves themselves as they soften). I've see my characins, dwarf cichlids, and small catfishes "grazing" continuously on their surfaces, making them a great candidate for any mixed leaf litter bed, IMHO!

Although our Jackfruit leaves are collected for us in an area that is free from pesticides or other contaminants, it's just good common sense to prep them before using in your aquarium. As with the other leaves we offer, we recommend that you rinse and/or steep them in boiling water before use, and add them gradually to your aquarium, so that you can gauge for yourself the impact they have on your water.

Our experience shows that they have a "tint capability" somewhere in between Guava and Catappa, although your results may vary, of course. This is a highly scientific assessment, of course (tongue firmly planted in cheek...)

As I talk about on a near-continuous basis here, the practice of adding terrestrial dried leaves and other botanicals to our aquariums for the purpose of influencing the environment and health of our fishes is growing and evolving daily. We're learning the good, the bad, and the erroneous attributes and implications of our craft.

Sometimes, it's just nice to take a minute or two to look at the materials that we've already had at our disposal, so that we can get a better picture of how they might fit into our next aquarium setup! (or vivarium or paludarium, as well! ). I hope this little love note to the Jackfruit leaf encourages you to give these guys another look when considering a mix of leaves for your botanical-style aquarium.

Until next time...

Stay curious. Stay experimental. Stay creative. Stay observant. Stay resourceful...

And Stay Wet.


Scott Fellman

Tannin Aquatics


Scott Fellman
Scott Fellman


1 Response

kate campbell-lloyd
kate campbell-lloyd

June 13, 2021

I found you by weaving my way through the world of tannins for eco plant dying of leaf imprints onto cloth…as a fan of jak fruit – a grower of the giant lemon sherbert & orange crunchy I just twigged they could be high in tannin and found you – thank you. I will now follow you and right now will add jakfruit leaves to my guppy aquarium and watch with interest!

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