Xenesthis immanis / Columbian Lesserblack Tarantula Care Sheet

Xenesthis immanis completely dispels the myth that all tarantulas are a boring, brown color. 

While the abdomen is clothed in bright pink-purple hairs, the carapace on Xenesthis immanis is even more impressive, possessing a bright metallic purple starburst pattern. Adult males can be particularly impressive, as they also develop purple femurs at maturity.

A fast-growing tarantula that attains a dramatic 7-8” as adults, this is really one of the most impressive tarantulas currently available to hobbyists. 

Unsurprisingly, as a result, it tends to be an eye-wateringly expensive tarantula to add to your collection. If you’ve got the readies, however, Xenesthis immanis is one spider that all serious tarantula keepers should own. And if that’s the case then read on for my Xenesthis immanis tarantula care sheet where you’ll learn exactly how I’m keeping my specimens…

Wild Habitat

As the name would suggest, the Columbian Lesserblack tarantula is a South American species. Far from being found only in Columbia, however, it may also be encountered in Peru and Venezuela. Originally described by Ausserer in 1875 it was classified initially as a Lasiodora species, which gives you some idea of the potential adult size. 

In the wild Xenesthis immanis is a burrowing species. It spends most of the daylight hours hidden away underground, coming to the surface as darkness falls to catch any passing prey items. 

While some specimens will happily burrow in captivity, I have found that the majority of my specimens don’t take the opportunity even when it is presented.

Xenesthis is quite a skittish species in general, and so if your specimen chooses not to burrow then they should be given a suitably-sized hide. 

Cages & Housing

Like many other South American terrestrial tarantulas Xenesthis immanis not only obtains a large adult size but also grows rapidly. 

A range of containers may be suitable, depending on the size of your tarantula and it’s behaviour in captivity…

Glass Tanks

Glass tanks look great and are pretty robust. If using a glass aquarium for your Colombian Lesserblack be sure to select one that offers suitable ventilation. Bespoke tarantula tanks do just this. 

Perspex Tanks

Perspex tanks tend to be lighter and cheaper to buy, but if you’re not careful the perspex can scratch very easily during cleaning. As a result, while they may look great to start with they can very quickly decline in quality. As with glass tanks, it is possible to build your own perspex tank very cheaply indeed if you’re on a budget.

Glass Terrariums

Glass terrariums make some of the best display tanks for many species of tarantula, though you’ll need to take into consideration the burrowing tendencies of this species.

If your Xenesthis immanis chooses not to burrow then a glass terrarium may be ideal, coming as they do in a range of different sizes. The vented lid makes for plenty of ventilation while the front-opening doors make routine feeding and maintenance a breeze.

Faunariums / Critter Keepers

Faunariums are plastic “boxes” with a tight-fitting vented plastic lid. While they’re certainly not the most attractive caging option available, they tend to be cheap and cheerful while permitting excellent ventilation. They can also hold a decent depth of substrate, which is ideal for burrowing tarantula species. 

Plastic Storage Boxes

I use a range of different plastic storage boxes for tarantulas in my collection, including many of my Xenesthis immanis specimens. These range from small deli cups for spiderlings and juveniles to large 9 to 15 liter tough plastic containers for larger specimens. Just be sure to modify them to permit proper air flow. I personally use an electric drill to add numerous air holes, though some keepers prefer to use a soldering iron in a well-ventilated room (be aware of fumes). 

Whatever tank you opt for, be aware that you’ll likely have to rehouse your Xenesthis immanis numerous times as it grows. Ultimately, for an 8-9” tarantula, a 30cm x 30cm tank is the bare minimum for an adult specimen; as a large species an even larger tank may be welcome. 

In terms of depth, if your specimen chooses to burrow then endeavour to provide a deep substrate to facilitate this.  

Heating & Temperature

At the time of writing I have half a dozen Xenesthis immanis specimens of varying ages and sexes. What I have found consistently is that this species seems to favour slightly cooler temperatures than many other species in my collection. They seem to thrive well at temperatures of 20 – 24 degrees Celsius (68 – 75 degrees Fahrenheit), though slightly higher temperatures are unlikely to cause any issues.

All my spiders are kept in a room where such temperatures are maintained around the clock, however if your home gets cooler then you may want to consider some form of artificial heating for your spider. 

Water & Humidity

I don’t worry too much about humidity levels with my tarantulas. My spider room sits naturally at 50-60% and this seems to work fine for all my spiders. 

All tarantulas should have a suitably-sized water bowl once it is safe to do so. I do not provide a water bowl for tiny spiderlings due to the practicalities, but for juveniles onwards I use anything from bottle tops, to shallow jar lids, to small deli cups as water bowls for Xenesthis immanis. The water should be changed regularly to keep it fresh and the “bowl” cleaned or replaced routinely for hygiene.  

Tank Decor

Xenesthis immanis have quite simple requirements in captivity; primarily enough substrate to permit burrowing if they opt to do so, and a suitable hide as an alternative place to hide away.

Substrate

I use coco fibre (coir) as a substrate for all my Xenesthis immanis. It is natural, hygienic, does a good job of absorbing water and looks great.

Alternative options are potting compost or topsoil, if you can be sure that no chemicals have been added. Some keepers opt to combine two or more substrates to get the consistency they’re seeking. 

If your Xenesthis immanis is to burrow then be sure to provide a suitable depth; ideally this should be at least the legspan of your tarantula.

As stated earlier, however, my specimens do not seem to burrow at all, even when the opportunity presents itself. As a result, it is wise to provide a physical hide. 

Hides

Provide a piece of cork bark or a plastic plant pot laid on its side, into which your Xenesthis immanis can fully conceal itself. Even then, your spider will likely only use it on occasion; I find this species to be far more visible than many of the “pet holes” we tarantula-owners lovingly care for.  

Sexing Xenesthis immanis

Xenesthis immanis can of course be sexed from sloughed moults as with other species, while the adult males possess standard palapal bulbs as well as the tibial hooks seen in many other species. However there are other techniques that can be worth knowing for this species.

Firstly, adult males change their appearance significantly upon maturity. You will notice that the femurs turn a brilliant purple color, matching the purple starburst pattern on the carapace. An adult male Xenesthis immanis really is up there as one of the most colorful and attractive tarantulas currently known in the hobby. 

Long before this, however, I have noticed in my specimens that the males generally look slimmer and more leggy than the females – even at quite a young age. If you’re desperate for a female but can’t find a sexed individual try visiting a reptile expo where you can compare multiple specimens with one another. The chunkier, more “thickset” specimens are more likely to be females in my experience.  

Food & Feeding

From Acanthoscurria geniculata to Lasiodora parahybana, one of the coolest things about keeping tarantulas from the tropical region of South America is their appetite. These guys always seem to be hungry and will throw themselves onto almost any food they can subdue.

The great thing about tarantulas like this is they also grow fast. This is a benefit for such an expensive tarantula; you can purchase a smaller (and therefore cheaper) specimen and watch it rapidly grow into a much, much larger spider.

Almost any standard feeder insects will be suitable. My personal preference is for a combination of locusts and roaches to vary the diet. While a once-per-week feeding is entirely suitable, this is a species with a big appetite so I feed my specimens twice a week without issue. 

Remember: the more they eat, the faster they’ll grow. This can be a useful technique should you buy a pair of a similar size; feed the female more to accelerate her growth rate, giving you the best chance of the pair maturing at breeding size.  

Be sure to remove any uneaten food from the cage, to prevent it stressing out your tarantula or dying and attracting mites. For such a skittish species a long pair of forceps is recommended for this task.  

Handling & Temperament

In terms of temperament I would Xenesthis immanis on par with Megaphobema robustum, also from Colombia. I wouldn’t call either species “defensive” or “aggressive” but they are quite skittish. Opening their cage can be enough to see them dashing out of view. Just like M. robustum they also adopt a “carapace down, abdomen up” posture when disturbed – presumably so they’re ready to kick off their urticating hairs if not left alone. 

I don’t recommend that any tarantula is handled as it puts the animal at risk. While I doubt this species would attempt to bite you if you tried, I would be worried that Xenesthis immanis would be at risk of bolting away from you, falling straight off your hand. 

Assuming you leave your specimen inside their cage then I wouldn’t regard this species as being particularly fast or aggressive. I would say that most tarantula keepers would have no issues maintaining this reasonably docile species. My specimens rarely if ever even try to kick off any urticating hairs from their abdomen. 

Just be sure to open their cage gently and move slowly when maintaining them to prevent them bolting and you’ll be just fine.  

Pros

• Big, impressive spider
• Amazing colors
• Reasonably slow moving
• Generally quite docile

Cons

• Expensive to buy
• Can be quite skittish
• Not really suitable for handling