How often do jumping spiders moult? 

Spiders are by far one of the most fascinating arthropods! Their body consists of an exoskeleton that is soft like human skin in some areas, and hard like plywood in others. This kind of inflexible structure is the ideal body armor in the animal kingdom, but how does a spider function in body armor that protects yet prevents the body from growing? The answer is moulting! Moulting is one of the most important moments of a spiders life, and is a necessary recurrence to ensure continuous growth.

The moulting process begins with your spider eating and storing as many nutrients as possible before the journey, while simultaneously building a thick moulting hammock. A moulting hammock has a narrow opening at the front and back, with thick walls of silk (almost to the point where transparency makes it  difficult to see your spider) and this structure is used to protect them during the process. You will also want to look out for dull coloration and what we call the side to side “butt dance”. This dance is a pretty good indication that your spider has saved up enough energy to start the pre-moult process and they will begin constructing their moulting hammock. Your spider will also begin to reject food the closer they get to completing their hammock, so it’s a good idea to entice and give extra offerings of food during this time to ensure they have enough reserves to survive the process of shedding their old exoskeleton.

Their behavior may become noticeably sluggish, and it is around this time that the laying down of the new cuticle (which is arranged in folds beneath the old one) will begin. The old cuticle is then dissolved from the inside by special enzymes known as chitinases and proteinases to a third of its original thickness. This creates a moulting gap between the old exuvium and the new exoskeleton, which is then filled with liquid. At this precise moment, the spider will begin pumping body fluid from the hind body into the front body, so that the latter is inflated and tears at natures predetermined locations of the body leaving only one anchor of security; the moulting thread attached to the spinnerets.

Your spider will begin a rhythmic pumping movement in its legs that behave like a hydraulic system allowing the extremities to reach their final new size, and the joints to remain full while the sclerotin of the new exoskeleton is slowly reproduced and hardens. If you're lucky and patient enough to witness this process, you will notice that your spider will be whitish in color. As the exoskeleton hardens it will go from pale, to tan, to brown, and even to black, all within an hours time depending on the species.

This entire process is comparable to a human going to a spa and getting a full body chemical peel, but this one comes with a death waiver; if a spider is unsuccessful in emerging from its old shell in the alloted time, it can lead to the fusing of the old and new exoskeleton which can lead to deformities, self-amputation, and even death. Should your spider self-amputate, don't panic! They know what they're doing and will have a chance to grow any missing limbs back during their next moulting cycle as long as they aren't an adult. To prevent this from happening, we recommend gently misting your spider's enclosure and hammock twice daily during moulting. This can help prevent dehydration which is one of the main causes for poor moulting conditions in jumping spiders.

The rate at which your spider will moult is highly dependent on how old they are. An Instar is a phase between two periods of moulting in a spider's life used to determine their age. Most jumping spiders are adopted out at instar 4 or 5. More experienced Jumper parents will adopt at instar 2 when the babies are called Slings or Spiderlings.

i6 - i8 Juveniles. For juvenile jumping spiders, moulting can take up to 2 hours.

i9 - i12 Sub-Adult. For sub-adult spiders, moulting can take 3-5 days.

i13 - i16 Adult. This is your jumping spiders last and final molt.

2-3 years old - Senior

If my Jumping spider isn't moulting correctly, what do I do?

Because of the delicate nature of moulting you may need to intervene if your jumping spider is an i5 or younger and has taken more than 30 minutes to complete the process. If they are still moving but also still stuck in their old exoskeleton it's time for triage. *I DO NOT recommend doing this without experience unless you do not have access to help as you may be risking the loss of your spider.  

Items needed:

• Clear 2-4 ounce condiment-cup *you can buy these in a massive pack, or you can go steal a few from your local Five Guys burger joint, sub-shop, or restaurant. Most people don't mind if you ask politely.
• Micro-misting spray bottle
• Cotton pads
• Safety-pin or thumb-tack

Step 1: Use a clear 2-4 ounce condiment-cup with a lid.

Step 2: Use a safety pin or a thumb tack to poke 4- equally spaced air holes into the sides of a condiment cup for airflow. Grab your Micro-misting spray bottle and gently mist the sides with warm water.

Step 3: Dampen the cotton pad with warm water and GENTLY place your spider on top of it. 

Step 4: Put them under a warm light (NOT IN THE SUN) and have patience. Allow your spider to wiggle themselves out.

Should your spider be successful in detaching themselves from their old exoskeleton, there can be an occasional mis-moult. This will be noticeable when a jumping spider will either have a deformity such as a misshapen or hooked leg, or in worse cases, they may have some limbs missing. While loss of limb is an obstacle don't fret! As long as your spider is not a fully grown adult, they will have the chance to grow back a proper limb during their next moult!

Remove LIVE prey during moulting  

Touching your jumping spider during moulting can lead to unwanted stress and can be detrimental to their survival; especially if they endure a fall. A fall during moulting can have deadly consequences. You will also want to remove all feeder insects once your spider has consistently rejected food; failure to do so will cause your spider to perceive a threat while in a vulnerable state, and they will be unable to focus on shedding their exoskeleton in time to separate properly. It’s also best to wait 48-72 hours to feed your spider after a fresh moult to avoid injury especially if you feed your spiders crickets. Crickets can, and will harm your spider if possible.

Hopefully by the end of this post we have helped you better understand the importance of a spiders moulting process, and why it is one of the most significant moments of a spiders life. Feel free to leave a comment if you have an questions that we didn't cover during the moulting process. We hope this post was helpful to you!