Mexican Flame Knee Tarantula (Brachypelma auratum) Care Sheet

At first glance the Mexican Flame Knee tarantula (Brachypelma auratum) closely resembles the far better-known Mexican Red Knee (Brachypelma hamorii/smithi). Look a little closer, however, and subtle differences start to become clear…

Whilst both species have vivid orange or red stripes on their “knees” it is the background color that effectively separates these two species. In Brachypelma auratum these stripes are presented on a black background, making them stand out all the more. This is in contrast to the Mexican Red Knee whose stripes are found on an orange or yellow background.

In addition to this subtle difference, Brachypelma auratum is generally much darker in appearance, and has far fewer of the bright orange hairs found on the abdomen of its close cousin.

To some people, the Mexican Flame Knee is even more attractive than its rather more showy and popular relative. Whatever the case, this species meets all the standard benefits that have made Brachypelma tarantulas such popular pets; bright colors, docile disposition, ease of care and a moderate adult size.

If you’re a diehard Brachypelma tarantula fan (as I am) but you’re looking for something just that little bit different then Brachypelma auratum may just be the perfect next spider for your collection. If you’re considering adding this species to your collection then read on for my detailed Mexican Flame Knee care sheet.

Brachypelma auratum Wild Habitat

At one time Brachypelma auratum was considered a subspecies of Brachypelma smithi, but we now know it is a separate species in its own right. The Mexican Flame Knee is a relatively recent addition to science, having only been described in 1992 by Schmidt.

In the wild, this endangered species is found in savannah and scrubland regions of Mexico. More specifically scientists believe it is endemic to the Guerrero and Michoacán regions. Tarantula expert Rick West states that it ranges from “central eastern Jalisco south through north eastern Colima and into central western Michoacan state”.

Like other Brachypelma species it seems that the Mexican Flame Knee tarantula is a ground-dwelling tarantula and typically seeks refuge from predators and extreme weather.

While this tarantula species has been less extensively studied than many other species, it is worth noting that it has been found living communally with a small frog known as Eleutherodactylus occidentalis. While this is far from unique, with other species such as Poecilotheria ornata found living with other species, it is notable as it further expands this concept of tarantulas living passively alongside other potential prey species.

The climate in Michoacan state is described as “tropical savannah” with temperatures varying between 16’C and 29’C though daytime temperatures are normally in the mid twenties. They have, however, been recorded at over 40’C which indicates just how sturdy this species of tarantula really is. Generally speaking the Mexican Flame Knee can be kept like the Mexican Red Knee, whose territories can often overlap.

Mexican Flame Knee Housing

Brachypelma auratum is not a difficult tarantula to keep in captivity and is quite forgiving in terms of its care. It is an average-sized tarantula reaching a legspan of around 5” on average, though some older females may get closer to 6”. This means that unlike some huge species like the Goliath Birdeater or the Salmon Pink more modest accommodation will work perfectly well.

I recommend a cage of no less than 10” x 8” for adults, with juveniles of course doing fine in comparatively smaller containers. Of course, there is nothing wrong with placing this species into larger cages; indeed as this tarantula seems to be quite happy to sit out in the open for long periods of time it can make a very attractive display animal.

Whenever possible I like to use cages of around 30cm long by some 20-30cm deep which can be well landscaped and offer the opportunity to behave in a more “natural” manner.

My favorite cages for all adult tarantulas including the Mexican Flame Knee are Exo Terras or ReptiZoo terrariums. These attractive glass vivariums offer a huge number of benefits. Firstly they have front opening doors that lock shut when not in use. This therefore offers both excellent security but also practicality when it comes to feeding and cleaning.

If you’re unable to find an Exo Terra a range of other cages may be used for your Brachypelma auratum. The entomological shows I visit each year often have specialist glass tarantula cages for sale at very reasonable prices.

If you’re in the UK feel free to check out a company called Custom Aquaria who I have been buying from for years. If you’re on a budget it is of course even possible to build your own tarantula tank from glass or perspex.

Lastly, a range of plastic containers can be used. For example, Kritter Keepers have potential for use, or you could just repurpose a tupperware box by adding air holes for ventilation.

Heating & Temperature

The Mexican Flame Knee is typically found in hot, arid parts of Mexico so a standard room temperature is totally unsuitable for this species. Apart from the hottest months of the year, where ambient warmth may be enough, some form of artificial heating will be necessary.

This should be set up in such a way that one end of the of the cage is much warmer than the other. A temperature at the hot end of around 26-28’C tends to work well for this species, though they should always have the opportunity to escape to a cooler area of their cage if desirable.

For some readers your home may already be warm enough to support this lifestyle. For others, however, some form of artificial heating may be required in winter.

The easiest and most cost-effective way is usually with a reptile heat pad that is attached to the side of the cage. Some heat mats now come with a self-adhesive surface, making it easy to stick them to the side of the cage.

Heating smaller tarantula cages can be rather more problematic because heat mats are only sold so small. Furthermore, you may find yourself like many tarantula keepers ending up with quite a collection of immature spiders that you’re raising to adulthood.

Water & Humidity

Overly soggy conditions should be avoided for almost all tarantulas in captivity, and especially so for Brachypelma auratum as it is attuned to drier environments.

Personally I spray the cages of my spiders once every week or so to temporarily raise the humidity level, before it is allowed to naturally drop down thanks to the combination of heating and suitable ventilation.

At the same time I ensure that all my larger tarantulas have access to fresh water at all times, thanks to the provision of a water bowl. Here I tend to use tiny water bowls as sold for hamsters, and ensure that the bowls are regularly cleaned, sterilised and refilled.

Try to place the water bowl at the cooler end of the cage to reduce the evaporation rate or you may find that the water quickly disappears.

Cage Furnishings

Brachypelma auratum is not a demanding tarantula to keep. Once you’ve bought the cage, heater, plant spray gun and water bowl there aren’t too many more pieces of equipment that you’ll be needing.

Primarily you’ll want to secure some suitable substrate to line the base of the cage and somewhere for your tarantula to hide away during daylight hours. A range of substrates are available, many of them suitable for Mexican Flame Knees.

I now almost exclusively use coir fibre which is reasonably priced, looks great and allows some burrowing if your tarantula chooses to do so.

In terms of a hide, two of the best options are either a curved piece of corkbark or a plastic plant pot laid on its side. Wherever possible I like to give my Brachypelma tarantulas at least two hides – one at the hot end and one where it is cooler so they can choose to rest where the temperature suits them best.

When choosing a hide take into consideration the size of your tarantula. The hide should permit them to fully conceal themselves beneath as they would in the wild, allowing them to feel safe and secure in their cage.

Mexican Flame Knee Feeding

Mexican Flame Knee tarantulas are quite slow growing, and so won’t eat as frequently as faster-growing species like Indian Ornamentals or Salmon Pink Birdeaters. Specimens of most sizes will happily eat a suitably sized insect once every 5-7 days though the driver of your feeding regime should be your spider itself. If they always seem starving hungry then consider feeding them more often, while if food seems of little interest to them then reduce the feeding frequency.

Brachypelma auratum will take any suitably-sized feeder insects from crickets to locusts and roaches. Personally I don’t like to feed crickets because there is some evidence that they may nip at your tarantula if uneaten, and can lead to problems if your spider decides to moult.

Try to remove any uneaten food the morning after feeding if it has not been touched. If you find that your tarantula refuses food for a period of time then it may be coming up to moult so you should take suitable steps to protect it at this most sensitive of times.

Handling Brachypelma auratum

The Mexican Flame Knee is typically quite a docile tarantula, and so can be handled safely. That said, be aware that like other Brachypelma tarantulas they do have urticating hairs on the abdomen that can be kicked off if your spider feels threatened. As a result, try not to hold your tarantula close to your face.

Also, appreciate that tarantulas that fall from a great height can rupture their abdomens, leading to near-instant death. Therefore if you opt to handle your Brachypelma auratum try to do so over a suitable surface like your couch or a bed, so that no damage occurs if it is unlucky enough to fall.

Picking up a tarantula is a reasonably simple process. Simply hold out your flat hand in front of them and then gently coax them into your hand. Most Mexican Flame Knee tarantulas will gently walk forward onto your hand where they can then be picked up.

Alternatively, of course, just because you can handle a species of tarantula doesn’t mean that you have to. Many tarantula keepers are happy to simply admire their pets within their cage, and if necessary to gently nudge them with a pen or a pair of forceps if they ever need moving.