by John P. Clare
Whether you intend to build a horizontal terrarium, or a vertical terrarium like these, the same basic requirements
and procedures apply. These terrariums each contain a breeding pair of Imitating Dart Frogs, Ranitomeya imitator.
Photo ©2010 John P. Clare / FrogForum.net
To the newcomer, building a dart frog terrarium or a tropical terrarium for other amphibian species can seem daunting. However, once you've constructed one, future builds are fairly straightforward. This guide will give you an overview of what is required to construct a dart frog terrarium, and we will cover the basic components and how to implement them. There are several useful resources on the web, and there are several books that cover the topic too. For a practical example of what's discussed in this article you may find it useful to read this thread on step-by-step construction of a vertical terrarium for thumbnail dart frogs. That thread also discusses creating a textured background for the terrarium. This article omits discussion of background construction. Hopefully there will be a future article on this aspect of tropical terrariums.
This article is aimed specifically at dart frog terrarium construction, but with the exception of the ventilation aspect, terrariums for tropical tree frogs and other tropical frogs can be built in the same way.
Constructing a dart frog terrarium like those pictured above will require the following materials:
- A suitably sized terrarium container - usually an aquarium tank or a product specifically sold as a terrarium, such as Exo Terra's Terrariums and Zoo Med's Naturalistic Terrariums. The terrarium needs to have a water-tight base, due to the day-to-day accumulation of water.
- A tight fitting lid that prevents the escape of fruit flies and other small animals (microfauna) that will share the terrarium with the frogs.
- Appropriate ventilation for the frogs in question - dart frogs require very little or no ventilation, and restricted ventilation is necessary to retain the humidity necessary to mimic the frogs' tropical rainforest home. The only exception to this restricted ventilation is if you have an automatic misting system or you religiously mist the terrarium daily in order to maintain a high, consistent level of humidity. For frogs other than dart frogs, more extensive ventilation is required because other frogs are prone to respiratory infections if kept in terrariums with low ventilation. A suitable lid can be as basic as a sheet of glass cut to cover the entire open part of the terrarium, though most hobbyists prefer to provide at least a small area of ventilation, such as an aluminium screen like those found in the 3 terrariums pictured at the top of this article. Exo terra and Zoo Med terrariums come with screen lids that require replacement or at least a piece of glass or plastic placed over part or all of the screen in order to restrict ventilation, as these terrariums are not designed with dart frogs in mind.
- Adequate sealing of doors and lids to prevent escapes of frogs and fruit flies, and to maintain humidity. For example, aquarium silicone can be applied to fill gaps in a door, and, once cured, a razor blade can be used to free the door's movement.
- A facility to remove excess water from the the terrarium. This can be as simple as a small pond in one corner (which we will deal with later in this article), a piece of capped PVC pipe extending to the base of the substrate, or a drainage nozzle installed in a hole in the glass near the bottom of the terrarium. Note that special drill bits and precautions are required when drilling glass, so do not attempt to do so without the proper research.
- Appropriate substrate, such as an aquatic soil product, tropical plantation soil, or ABG mix.
- Appropriate drainage layer material, if you wish to provide a drainage layer (the so-called "False Bottom"). Suitable materials include LECA (Light Expanded Clay Aggregate, which is sold some times as Hydroton), Hydroballs, Featherlite, and the plastic diffuser material sold for lights, also known as egg crate.
- Fiberglass Window screen mesh or similar safe material to prevent substrate material getting into the drainage layer.
- Leaf litter for microfauna, frog hiding places, and frog security. Leaf litter should be chosen based on how long it takes to decompose - the longer the better - and its safety for frogs. Popular choices include magnolia leaves, "Live Oak" leaves, Indian Almond Leaves, and Sea Grape Leaves, but there are many other possibilities.
- Cork bark or other suitable water-resistant wood in order to section off a pond like that shown in the diagrams that follow.
- Wood that will stand up to the tropical conditions of the terrarium without molding significantly or decomposing too rapidly. Suitable woods include Mopani Wood, Manzanita, Ghost Wood, and Malaysian Driftwood. Grape Wood, commonly sold for reptile terrariums, does not last very long in tropical terrariums and it has a tendency to mold repeatedly during its lifetime in the terrarium. Therefore, Grape Wood should be avoided.
- Tropical plants such as small bromeliads, pothos, Peperomia, Philodendron, Fittonia, Ficus, Dischidia, Hoya, etc. The choices here are extensive and will not be covered in this article. Suitable plants for water areas in the terrarium include Java Moss (Vesicularia dubyana) and Riccia (Riccia fluitans). Riccia has the added benefit of colonizing moist land areas and creating a beautiful green carpet, though it requires very good lighting to achieve this.
- Hiding areas appropriate to the type of dart frog. For example, coconut huts are commonly used for large dart frogs like Dendrobates tinctorius, D. leucomelas, D. auratus, and frogs from the genera Phyllobates and Ameerega. For thumbnail dart frogs like Ranitomeya imitator, film canisters strategically placed around the terrarium are a better choice, and thumbnails also like to hide in bromeliads.
One final consideration to keep in mind is heating. If your terrarium will be in cool room, or becomes cold in the winter (below about 65 °F / 18 °C), you may need to examine heating options while designing your terrarium. Perhaps the best approach is to use a thermostatically controlled, water-safe heating cable in the substrate or drainage layer. It's difficult to add an internal heating option to a terrarium after it is in use, so explore the options before you begin construction.
Tropical terrariums that have moist/humid conditions invariably accumulate excess water in their substrate layers. This can lead to water-logging, rotting of the substrate, and proliferation of an excess of anaerobic bacteria that can pose a danger to the terrarium inhabitants and plants. Dart frog enthusiasts and hobbyists who keep tropical tree frogs usually employ a false bottom to deal with this excess water.
A false bottom consists of a drainage layer below the actual terrarium substrate. Water drains through the substrate and accumulates in this drainage layer, away from the substrate itself. Normally, most of the excess water is drained periodically to prevent it reaching the substrate. As discussed earlier, this can be accomplished in several ways. The example presented here is the corner pond - this gives us easy access to the water table and it also provides a water body into which the larger varieties of dart frog can deposit their newly hatched tadpoles. When constructing a false bottom, light, low-density materials are usually employed. You could use gravel or pebbles, but these are significantly heavier than the materials listed earlier - an important concern when it comes to moving a terrarium. My personal preference is LECA because it is the least unsightly and easiest to install.
Industrious amphibian enthusiasts often bury or seclude an aquarium pump in the false bottom in order to power a water fall, drip wall, or mock stream. Flowing water can help maintain high levels of humidity, and reduce the levels of anaerobic bacteria in the water table, due to the increased rate of gaseous exchange provided by the water movement. However, a broken water pump is often challenging to remove from the drainage layer, and you must also allow the cable to exit the terrarium without providing an escape route for frogs and fruit flies. Water features can help beautify a terrarium, but are of little practical advantage, and the hobbyist should ask himself/herself if the effort and risks of installing the water feature are worth the benefits.
Here is a pictorial guide to building a basic dart frog terrarium, minus background, lid construction, and landscaping. The terrarium pictured is a replica of how I maintain and breed Dendrobates tinctorius, and how I keep Phyllobates terribilis.
A layer of LECA or other drainage material is added first. The depth is not too important but should be at least 1 inch (2.5 cm). The deeper the drainage layer, the less frequently you will have to remove excess water, but deeper drainage layers take vertical space away from the rest of the terrarium. Note that a space has been left in the corner to create a small pond, as discussed earlier in this article. Holding the LECA in place during construction is difficult, so to prevent it rolling into the space, place an object in the terrarium until the LECA has been secured in place.
A sheet of fiberglass window screen mesh cut to the area of the drainage layer surface is placed on top of the drainage layer. If you are constructing a pond as we are doing here, cutting a larger piece of window screen to wrap around the pond edge and underneath the drainage layer will help immensely to keep the drainage layer in place. The mesh prevents soil/substrate particles getting into the drainage layer.
A piece of cork bark is used to make a bank for the pond area. This is optional but helps to keep the substrate and drainage layer away from the pond. The cork bark can be cut with a hack saw. Note that it is much higher than the drainage layer, to take into account the depth of the substrate layer we will put in place later.
This step is optional, but I like to put a thin layer of coconut husk chips (the big chunky stuff) on top of the mesh to prevent very fine substrate particles getting into the drainage layer. It also provides a buffer between the actual substrate and the drainage layer, and helps to wick water between the layers.
Next we add the substrate. I use pre-moistened ABG mix, but you can use other materials like aquatic plant soil as discussed earlier. I like to use at least 2 inches (5 cm) of substrate proper. This is where your microfauna will live, and where your plants will root. Note how in the diagram the substrate layer is not just a flat, boring layer. This also helps to provide variations in moisture levels and differences in cover - I find that breeding "houses" placed in the dips are favored as egg deposition sites by Dendrobates tinctorius. Now is also a good time to add springtails and/or isopods.
Now we've added a nice layer of leaf litter. I like the smaller leaves like "Live Oak" for smaller dart frog species and froglets, and larger leaves like Magnolia for larger frogs. A mixture of sizes is even better.
Two coconut huts make good hiding spaces for larger dart frog species. If you place a petri dish or a round lid from tupperware (plastic food container) under the coconut hut, it makes an ideal egg deposition site. Ensure the lid or petri dish is slightly larger than your coconut hut so that it can receive moisture from misting.
Finally, spray the whole terrarium down with water so that there is a decent water level in the pond (and, because they are not sealed off from each other, the drainage layer).
If you have a suitable lid ready, the terrarium can now be populated with dart frogs. Most enthusiasts will prefer to plant the terrarium before introducing dart frogs, but the terrarium has reached a functional stage. You can also add terrarium wood and affix film canisters to the terrarium walls, if appropriate to the species of frog you intend to house.
I hope you've found this guide useful. If you have any questions or comments directly related to this article, please make use of the comments form below. For individual terrarium construction issues, please start your own thread in the Vivarium, Terrarium and Enclosure Discussion area. Happy building!
First published on Tuesday August 24th 2010.
Article is ©2010 John P. Clare - FrogForum.net. All rights reserved. This article may not be reproduced or published in part or in whole without written permission from John P. Clare.
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