Tarantulas are arthropods – a group of animals characterised by their tough outer skeleton. While this exoskeleton provides support and protection, it also makes growth very difficult indeed.
Tarantulas shed their skin regularly. The process of shedding their skin is necessary for the tarantula to grow. It is also an opportunity for the tarantula to replace missing body parts such as legs or mouthparts.
How Often Do Tarantulas Shed Their Skin?
Most adult female tarantulas shed their skin once a year. This occurs in response to environmental triggers such as differences in temperature and humidity.
Adult male tarantulas typically have a very short lifespan. They rarely reach their next annual moult after reaching maturity.
Occasionally an adult male tarantula will survive long enough to attempt to moult again. This is often referred to as a “post-ultimate moult”. This generally doesn’t go well, with the specimen either dying during shedding, or losing body parts.
Younger tarantulas shed far more frequently. This makes sense as the tarantula is growing rapidly so regularly needs a new set of “clothes”. It is perfectly normal for smaller tarantulas to moult every few months.
As tarantulas get larger so the regularity of these sheds can decline. Generally speaking the bigger the tarantula the less frequently it will shed.
Why Do Tarantulas Shed Their Skin?
Shedding seems like a mammoth task for a tarantula. So why do they bother to shed their skin in the first place?
Think of your tarantula’s exoskeleton like a suit of armour. It may offer protection from predators and may reduce the chances of dehydration but your tarantula cannot grow properly. Imagine our knight putting on weight, and his armour getting ever tighter. Soon enough he’ll want to upgrade to a larger set.
When tarantulas shed, they split open their existing tough outer skeleton and emerge from within with a new soft, pliable version. Once safely out of the old skin the tarantula inflates the new exoskeleton and allows it to harden.
The end result is a much larger tarantula. Many keepers are astonished at just how much their tarantula manages to grow after a single moult.
Repair of Missing Body Parts
Tarantulas are able to regrow missing legs and other body parts during a moult. They can also replace any urticating hairs that are missing from their abdomen.
Missing legs may take a number of moults to regrow to full size. In the meantime a regrown limb may appear smaller or less colourful than the original limbs. With each successive moult, however, this regrown limb will get bigger and stronger. Eventually it will be indistinguishable from the other legs.
Preparation for Reproduction
Shedding has an important role to play in the reproduction of tarantulas.
Male tarantulas do not become ready to mate until they pass through a special moult. This is often known as their “ultimate moult”. At this point male tarantulas develop the reproductive organs they’ll need to mate with a female.
Shedding can also affect reproduction in female tarantulas.
When a female tarantula moults it doesn’t just shed its outer skin, but also the lining of the reproductive organs. The end result is that female tarantulas become virgins each time they moult.
The sooner after a moult that a female tarantula manages to mate, the greater the chances she will successfully produce fertile eggs.
How Long Does It Take for a Tarantula to Shed It’s Skin?
The process of shedding can take many hours for a tarantula, depending on the size and species in question.
In my collection many specimens turn over to start the moulting process in the late afternoon or early evening. They then progress through the evening, to be found fully moulted the next morning.
Should You Handle a Tarantula After Shedding?
The exoskeleton of a freshly-moulted tarantula is soft and pliable. This is a dangerous time for tarantulas, where predators or parasites will find it much easier to attack them. The tarantula itself may also struggle to move about properly until the exoskeleton hardens.
Moulting is therefore a stressful and risky experience for most tarantulas. It is best to give your tarantula the time to recover from such an ordeal. Do not disturb the spider for some time after a moult. This means no handling, and also no provision of food.
Some weeks after shedding you should find that your tarantula has fully recovered, and has got their appetite back.
A very good sign is if your tarantula brings it’s old sloughed skin out of the hide and dumps it somewhere in the corner of the cage. At this point you can be reasonably confident the tarantula has recovered fully, and is ready to start feeding again.