Instars (L/i) explained.
Instead of measuring age in months or years, like we would with other animals, we measure age in jumping spiders using instars. L stands for larval stage, and i stands for instar, but people use L or i interchangeably a lot in regards to jumping spiders. The number will tell you the amount of moults your spider has had. So i6 or L6 means that your spider has had 6 moults.
Every time a jumping spider moults, they move up an instar.
Sizes of jumping spiders of the same instar can vary a lot, especially between different locales, so there is no way of knowing which locale your spider is without asking your breeder.
Jumping spider life cycle
Eggs
The female jumping spider will lay her eggs, and cover them with silk to protect them.
Eggs with legs
As the eggs develop they start to grow legs and other features. They will still be pale yellow at this stage.
L1
At this instar, the babies will start to change colour from pale yellow to black, but their abdomens will remain round in shape. At this point, the spiderlings are not ready to leave the nest, and mum may scoop any that try to pop out early back into the nest.
L2
At this instar, the babies will have larger heads than bodies, and will start to look more like the spiders we know and love. They will remain completely black, and will have developed spinnerets. At this time, they will start to leave the nest in search of their first meals, and start to create little hammocks of their own.
L3
At this instar, the babies will start to get their iconic colourations.
L4
At this point, spiderlings under my care are given their own enclosure to grow on in, where they will repeat the process of eating, and moulting, going up an instar several more times.
Adulthood
Whilst there is no set amount of moults until adulthood for jumping spiders, in my experience, it seems to be around 10.
