Tarantulas undergo molting, also known as ecdysis, a biological process where they shed their exoskeleton. This shedding allows tarantulas to grow, as their rigid outer covering does not expand. Molting is essential for their development and survival.
The Purpose of Molting
Molting serves several purposes beyond just growth. Since their hard exoskeleton cannot stretch, shedding it allows the tarantula to increase in size. This process also enables tarantulas to repair injuries, such as regenerating lost limbs or damaged fangs. Additionally, molting replaces worn sensory hairs and refreshes their external protective layer.
Frequency and Influencing Factors
The frequency of molting varies considerably. Younger tarantulas (slings or juveniles) grow rapidly and molt more frequently, sometimes monthly. As tarantulas mature, their growth rate slows, and so does their molting frequency; adult tarantulas may molt once or twice a year. Adult male tarantulas typically molt only once after reaching maturity, contrasting with females who can continue to molt throughout their lives.
Species differences also play a role, with some tarantula species growing faster than others. Environmental conditions like temperature, humidity, and food availability also influence molting frequency. A well-fed tarantula kept in optimal conditions will molt more regularly.
Recognizing Premolt and the Molting Process
Recognizing premolt signs helps owners anticipate this sensitive period. A common sign is a refusal to eat, which can last for several weeks, particularly in adult tarantulas. The tarantula may also become lethargic and less active, often hiding. A darkening of the abdomen, especially in species with a “bald spot,” indicates the new exoskeleton forming beneath the old. Some tarantulas, particularly New World species, may spin a dense silk “molting mat” on which they will lie.
When molting begins, the tarantula typically lies on its back, a position that can appear alarming but is normal for this process. During ecdysis, the old exoskeleton splits, often around the carapace and abdomen. The tarantula slowly extracts itself from its old exoskeleton. This process can take 15 minutes for spiderlings to several hours, or up to 24 hours for larger adults. The tarantula is vulnerable during this time, and it is important not to disturb it.
Caring for a Tarantula After Molting
After molting, the tarantula’s new exoskeleton is soft and delicate. This new exoskeleton needs time to harden, a process called sclerotization, which can take several days to over a week. During this recovery period, avoid handling the tarantula, as its soft body can be easily injured. Fresh water should always be available, as hydration aids in recovery.
Do not feed the tarantula until its new exoskeleton, especially the fangs, has fully hardened. Introducing prey too soon can lead to injury, as the tarantula’s fangs will be too soft to properly subdue food, and prey items could potentially harm the vulnerable spider. For adult tarantulas, wait about 10 days before offering food, while slings may be ready in 3-5 days once their fangs appear black and firm.