We talk so much about the use of botanicals for their aesthetics and functional attributes (as in the tannins, humic substances, and other compounds they impart into the water) around here, but one of the things that we don't talk about enough is the use of botanical materials as food; or "food culturing" vehicles in our aquariums.
The simple reality is that likely many fishes may graze on the epiphytic growth of biofilms and algae which accumulate on the surfaces of most of these materials after they've been down for a while. It's no secret that shrimp, in particular, are big consumers of these growths, and will spend most of their day grazing on them. Of course, there are some botanicals that, by virtue of their structure or composition, which seem to accumulate more biofilms and such.
And of course, the inherent issue with a "review" of this nature is that it sort of looks like a "sales pitch" for the botanical materials we offer...Well, there's no way around that, right? I mean, we've curated our collection based on materials that work for us and for others, so it goes without saying that we will discuss them. Sure, some of these may be collected and/or ordered from other sources online and elsewhere.
Obviously, leaves come to mind immediately. Most any leaves will soften and recruit growth over time, some better than others. After many years of playing with a variety of leaves , I've formulated some opinions about which ones are the best.
Here are my top choices, and why:
Mulberry Leaves: We love these leaves because they serve no purpose other than to serve as food. It's long been known that Mulberry leaves provide carbohydrates, fiber, and essential nutrients, such as phytosetrols, which are essential to shrimp for optimum health and reproduction. Mulberry leaves are surprisingly nutritious supplemental foods for shrimp, as they're packed full of vital nutrients, like Vitamins B1, B2, B6, and Vitamin C, as well as carbohydrates, fiber, amino acids, and elements such as Magnesium, Potassium, Zinc, Iron, and Calcium.
Jackfruit Leaves: These leaves contain phytonutrients, such as lignans, isoflavones, and saponins that have health benefits that are wide ranging for humans. There is some conflicting data regarding jackfruit's antifungal activity. However, the leaves are thought to exhibit a broad spectrum of antibacterial activity. In traditional medicine, these leaves are used to help heal wounds as well. Do these properties transfer over to our fishes and shrimp? We are not aware of any scientific studies that have been completed to correlate one way or another. That being said, they seem to flock to these leaves and graze on them and on the biofilms which accumulate on their surface tissues.
Malaysian Bamboo Leaves: Although I'm not aware of specific nutritional benefits that these leaves offer to shrimp, I have seen shrimp spend hours and hours "working" their surfaces. These are very durable, long-lasting leaves, which do recruit biofilms and epiphytic algal growths after prolonged submersion. Bamboo is found in many environments from which shrimp hail, so one could (Well, I AM!) make the assumption that they are leaves which are "familiar" to them, and that grazing on the growths which cover them, or even consuming them is a part of their natural diet.
Magnolia Leaves: These long-lasting, beautiful leaves have long been popular for providing an aesthetic to the aquarium, both with their "generic tropical" sort of look once submerged, and for the tint that they impart into the water. Unique among the leaves that we offer, they have a sort of waxy "cuticle" which enables these leaves to "recruit" a lot of biofilm when submerged!
Magnolia grandiflora (the species we typically offer) produces phenolic antimicrobial chemicals, compounds called coumarins and sesquiterpene lactones, which discourage predation and grazing by terrestrial insects. Coumarins have known anti fungal properties. We can't help but wonder if these same antimicrobials and antifungals might provide some sort of benefits to fishes in a similar fashion to those attributed to Catappa, but this is just conjecture on our part; we are not aware of any specific scientific study on the matter, nor of the existence of data to confirm this theory. Fun to speculate, though!
And of course, there are numerous botanical materials besides leaves which fulfill similar purposes in the aquarium. Here are just a few of our faves:
Dregea Pods: Yes, the dreadful genus name sounds decidedly unappetizing, but there is something about these botanicals which shrimp seem to love! They have a very interesting "ribbed" exterior and a contrasting interior structure. The aforementioned "ribbed" exterior surface does a great job "recruiting" these biofilms after the pod has been submerged for a while. And the smooth interior tends to soften after preparation and submersion, offering fishes an (apparently) easily-consumed, highly palatable food source.
The fruit follicle-which we call a "pod" in our game- is known to contain many different secondary metabolites (aka "Anthocyanidins"- Delphinidin, Petunidin), Flavonoids (Rutin, Myricetin, Quercetin, Luteolin, Apigenin, Orientin, and at least one unidentified flavonoid), and Phenolic compounds. Sounds vaguely familiar, right? I'm recalling from Catappa...
And further phytochemical evaluation of the Dregea fruit revealed the presence of alkaloids, Terpenoids, Steroids, Coumarins, Tannins, Proteins, Phenolic compounds, as well as carbohydrates, glycosides, starch, phytosterol, lipids, amino acids, and lignins.
Dysoxylum Pods: Of course, what we call a "pod" is really the woody fruit capsule of Dysoxylum binectariferum. Botanists will tell you that the fruit capsule is 5-8 x 6 cm in length, red, "obovoid", depressed at the apex, and smooth in texture. The outer surface remains quite firm, while the inside will soften and ultimately attract significant biofilms once submerged. We've found over the years that ornamental shrimp, in particular, really take a liking to these pods, devouring the soft interior and the resulting biofilms which it recruits over time.
Interestingly, compounds derived from the tree are also known by modern medical researchers to have extremely valuable medicinal properties...Dysoxylum binectariferum bark was identified as an alternative source of CPT, through a process of bioassay-guided isolation. Camptothecin ( known to clinical researchers as "CPT 1") is a potent anticancer product, which led to the discovery of two other clinically used anticancer drugs, Topotecan and Irinotecan. Does this translate to health benefits for fishes and shrimp? I don't know, but I DO know that they love these pods!
Pyrifolium Pods: We love these botanicals, because they have the appearance of a leaf, but have the "heft" that you'd expect from a seed pod. Derived from the Aspidosperma pyrifolium tree from Brazil, They have a wonderful, "teardrop-like" shape. Most important, the interior of the pod tends to soften significantly when submerged, and is apparently irresistible to our little shrimp pals. This, of course, makes them very interesting to us as well!
Of course, there are dozens and dozens more botanical materials which shrimp and fishes love to graze on or consume, and we've barely scratched the surface of even our own collection here. I could literally just toss up the whole catalog of botanicals we offer and assert that shrimp and fishes will graze on them. You'll note that I didn't even touch on the popular and useful Alder, Birch, and Casuarina Cones, all of which are very useful for these purposes and more.
The same could be said for the various bark varieties that we offer. Their primary "attraction" is aesthetics and environmental "enrichment" (ie; they add a lot of "tint" to the water!); however, like everything else that we play with, they will provide supplemental neutron and grazing for...someone- right?
So, this is the briefest of summaries of what botanicals work for food and fun for your fishes and shrimp. You no doubt have other ideas and practices. And that's the beauty of this! It's an ever-evolving concept.
Keep searching. Keep experimenting. Keep sharing.
Stay curious. Stay diligent. Stay open-minded. Stay excited...
And Stay Wet.