Upon returning to the practice of herpetoculture last fall after a ten year hiatus, I immediately noticed a stronger emphasis on bioactive setups in the mainstream. Though keeping snakes in racks is still the norm in many circumstances, and something that has its place in unique contexts, I am grateful to observe the beginnings of a sea change within the broader community that prioritizes enriched, individualized, naturalistic husbandry for all species. This, in my experience, is the most rewarding pursuit when it comes to keeping reptiles, and thanks to a number of accessible resources, dedicated hobbyists, and focused companies, it is more achievable than ever before.
Over the past year, I have maintained a bioactive system for puffing snakes in a 6' x 4' x 2' (height by width by depth) enclosure and have greatly enjoyed the process and practice of building and attending to this system. Next year, I will be upgrading the enclosure to an 8' x 7' x 3' bioactive system, using plants native exclusively to the Guyana Shield region, where the puffing snakes in my care originated. I look forward to sharing the process of that build when the times comes. In this post, I aim to offer one small contribution to the practice of bioactive herpetoculture as I have explored it thus far, with the hope that I can help to make the process and rewards a little easier to come by for anyone interested in setting up a neotropical bioactive system.
Both literally and figuratively, the foundation of any thriving bioactive setup is the substrate. For neotropical vivariums, a substrate with good drainage and relatively low nutrient content is preferred, and many commercial substrates and blends can be utilized - perhaps the most applicable in this context is the well-known ABG blend. However, to save some money and gain a better understanding of the substrate I use, I tend to blend my own. A mixture of peat moss, long-fiber sphagnum moss, play sand, charcoal, leaf litter, and fir bark has worked very well in my enclosures over the span of the last year. The ratio by volume which I use (adjusted as necessary) is as follows:
As with any substrate, organic and additive-free components are a must to avoid exposing enclosure inhabitants to potentially harmful chemicals.
Given their humidity requirements, most neotropical setups benefit from a bottom drainage layer, for which I use clay hydroballs. However, for the enclosures featured in this post, I have not used a drainage layer and have experienced good results by carefully monitoring the moisture content of the substrate (and by utilizing cork rounds as planters for the larger plants). I aim for soil that is moist, but not wet, and occasionally turn the substrate to blend it and redistribute moisture and nutrients.
A generous layer of leaf litter over the top of the substrate helps to maintain humidity, provides microclimates, food, and habitat for microfauna, and encourages natural foraging behavior in some species of reptile. It also strongly contributes to the appearance and feel of the rainforest floor.
Many bioactive suppliers offer live oak, sea grape, and magnolia leaf litter, a combination of which looks great, and I have also harvested my own leaves of willow, madrone, or other non-toxic species. For those who harvest their own leaves, it is important to ensure they are collected from an area that is not exposed to pesticides or herbicides, and some keepers would additionally recommend boiling any collected leaves to sanitize them before adding them to the enclosure.
The addition of microfauna can serve a number of beneficial functions in any enclosure, and in the minds of many, represents the distinction between a naturalistic display and a bioactive system. Small invertebrates in particular, such as springtails and isopods, perform a number of helpful functions, from reducing odors by devouring fecal waste generated by enclosure inhabitants, to cycling nutrients and making them bio-available to vivarium plants.
Dwarf white isopods fare well in neotropical vivariums and can
often be found hiding beneath cork slabs, or amongst the leaf litter.
I have added several forms of microfauna to my puffing snake enclosures, some of which have fared better over the long-term than others. Springtails (Folsomia and Collembola sp.) have done exceedingly well, and their numbers have steadily increased over time to inhabit every part of the enclosure. I have also added several species of isopod over the months, and in my circumstances, have found that dwarf white (Trichorhina tomentosa) and powder orange (or powder blue) (Porcellionoides pruinosus) fare best in the longterm. Both springtails and isopods require some time to fully establish themselves in a large vivarium - in this case, it took about three months.
Believe it or not, there are several springtails congregating on this leaf!
Though diminutive, they have a profoundly beneficial impact in a bioactive system.
Microfauna benefit from occasional feeding to generate larger and more robust populations. Water-rich vegetables such as potato, carrot, or cucumber can be fed in small amounts, alongside a broad variety of commercial microfauna foods and supplements. Though microfauna will feed on fecal waste and urates generated by enclosure inhabitants, I still recommend spot cleaning and turning the substrate as needed to remove large segments of solid waste. This helps to reduce the overall nutrient load of the system and avoid foul odors.
Live plants are a vital component of any bioactive system and support a variety of functions - from helping to maintain humidity, to providing climbing, hiding, and basking opportunities, to creating a beautiful and attractive display. In addition, I find that live plants strongly encourage a variety of natural behaviors in puffing snakes. Each time a new leaf or flower opens, it is not long before the snakes are actively investigating the slight change to their environment - a consistently gratifying observation to witness as a keeper. The plants also help to provide dappled light and basking gradients which the snakes in my care readily utilize. One female in particular strongly prefers to drink off of recently misted leaves.
Basking beneath the dappled light that the foliage provides.
The author's adult male puffing snake, caught in the act of investigating a newly opened leaf.
When designing an enclosure and selecting plants, I tend to research common houseplants native to the region from which the species being kept originates. In the case of the puffing snakes, an incredibly broad array of plants applies, as they inhabit the greater Amazon Basin - perhaps the most biodiverse region on the planet. From that research, I make a plant list of those plants which appeal to me, making sure they satisfy the functions on the three levels described as follows:
- Primary plants are the largest plants in the display and/or plants which are showcased front and center. They are typically planted low in the enclosure, either directly into the substrate or in planters. When planters are necessary, I utilize large cork rounds for a more natural look.
- Vines, trailing, and shingling plants are typically small to medium sized plants, which are best positioned high in the enclosure and allowed to trail downward, or low in the enclosure and encouraged to climb upward through branches or a similar supporting structure. Some species may be mounted as epiphytes, while others may require planters mounted in the branches or enclosure decor - I have found cork tubes (plugged on one end and filled with substrate) function well for this purpose while maintaining a natural and attractive appearance.
- Epiphytes are smaller plants which can be mounted directly to branches or enclosure decor and which typically do not require substrate to thrive. I utilize epiphytes, usually bromeliads, as accents throughout all levels of the enclosure, and many species look particularly nice in upper branches below bright light.
A bromeliad mounted directly to a cork branch - note the offset or "pup" on the left.
The following is a plant list of Central and South American species used in one of my enclosures, which currently houses 1.1 adult Spilotes sulphureus:
In terms of maintenance, live plants don't require a great deal of input, in my experience. Infrequent pruning and harvesting of offsets (from established bromeliads) as needed is the bulk of the work, with the occasional addition of safe, organic fertilizer to encourage plant health and vigor. I often use cuttings to propagate additional plants or otherwise turn them into the substrate or leaf litter to decompose and feed the microfauna. Plants typically grow best under bright light (6000K color temperature), which is easily accomplished using either LED or T5 lighting, or preferably a combination of both.
After exploring bioactive systems over the past year, I feel that the longterm benefits of this style of husbandry far outweigh the initial inputs and maintenance required, especially in comparison to more sterile, laboratory-style conditions. Sterile systems serve a function within the hobby, particularly during quarantine or when illness strikes, but they fail to provide variation and enrichment, factors which encourage vigor and a widespread array of natural behaviors in captive specimens. To observe such behaviors is a gratifying experience, which instigates a positive reward system for both the keeper and the kept. I hope that this post has been a helpful resource in making bioactive systems a bit more approachable, and I welcome feedback and communication if any clarification is needed.
Here are some photographs of the system after one year:
Altogether, the enclosure measures 6' tall, 4' wide, and 2' deep, and can
be divided into two separate units by closing a pass-through in the back right.
The upper unit.
The lower unit.