Arachnoiden is located in north-central Massachusetts. We import, raise, breed, and sell tarantulas. We buy most of our species from German private breeders and arachnologists who maintain hundreds of captive-bred lines. Germany’s arachnid shows attract breeders from around the EU and buyers from around the world. New hobby species are often introduced there.

Virtually all our Brachypelma and Tliltocatl are bred in Mexico.

You’ll find our species listed alphabetically on a single, scrollable column, subdivided into spiderling, juvenile, immature, and adult categories. Experienced keepers will appreciate this layout. All specimens beyond juveniles are sexed.

In addition to a wide and changing selection, we provide photographs and short essays. Essays are written to help place a species in its natural setting. May they motivate you to critique your care sheet or improve your breeding plan. Information comes from a variety of sources, typically overseas and US breeders, field collectors, arachnologists, arachnology texts, and original scientific manuscripts. The most important statements have references or hyperlinks. Hobbyist and personal experience are given if helpful.


Safety for the owner goes hand in hand with safety for the spider. Internet photos of people holding tarantulas, even decorating their heads and faces with them, demonstrate risk to human (a bite and/or flicked urticating hairs) and tarantula (injury, stress). Photos don’t show the tarantula being flung across the room when handling goes awry. If you want to handle your pet, get a cat.

Bites from New World tarantulas are painful and associated with local inflammation, akin to a wasp sting. Bites from Old World tarantulas may in addition cause neurologic symptoms, sometimes lasting weeks. All tarantula bites have potential to cause more serious symptoms should an allergy to venom exist. Fortunately, thus far, there have been no reports of death from a tarantula bite.

Many New World tarantulas will flick urticating (itchy) hairs from their rumps when disturbed. These hairs have potential to land on skin, eyes, or be inhaled. Self-limited, local irritation is the most common result. Rarely, consultation with an ophthalmologist or other medical professional is required.

Safety issues can be complex. If in doubt, seek medical attention.

Starting in the hobby

For those of you new to the hobby, welcome! Here are a few tips to facilitate your venture into the field:

There are many sources of reliable information, but time-tested The Tarantula Keepers Guide (TKG) by Stanley and Marguerite Schultz has helped thousands of hobbyists with the basics. It is worth reading before your first purchase.

Whether you plan to keep one species or one hundred, spiderlings are generally the most economical investment. Like any young animal they require slightly more care. For some, it’s part of the fun. Once you’ve learned the basics, we are happy to answer specific spiderling husbandry questions.

Because female tarantulas live 2-5x longer than males, collectors prefer females. Tarantulas aren’t easily sexed as spiderlings, but sexing by molt and ventral examination become easier and more reliable with increasing size.

Sexing and cost

We raise spiderlings to a size where sexing is reliable by molt and/or ventral examination. At this point we’ll remove a species from the website and a short time later list it under females, males, or pairs. Because hobby collectors far outnumber breeders, males are not often listed. We do list and sell a few, but most go unsold. Decreased male saleability and male egg-sac bias, up to 70% in some species, are two reasons why females cost 2-3 times more than their unsexed counterparts.

Sexually mature males are sometimes available. We list molt dates to the nearest day, week, or month.


We use anterior-posterior leg-span, with size ranges reflecting variation in a given batch. A 1 1/2″ Xenesthis is a leggy, months-old lightweight, whereas a 1 1/2″ Grammostola is several times heavier and a few years old. A 1 1/2 inch Cyriocosmus dwarf may be sexually mature.

US collectors

We are happy to consider purchasing or trading for any species you’d like to offer, the exception in some cases being species that cannot be easily identified by visual inspection. Please include delivery in your proposal. We can help with shipping materials and technique for first-time shippers. Shows are an excellent way to trade, with no packaging and shipping involved. Feel free to drop us a line shortly before an upcoming show.

US breeders

We are happy to consider purchasing or trading for spiderlings from US breeders. We may ask you for photographs of mother and father if you are new to us, and ask you to include delivery in your proposal. As above, shows are an excellent venue for direct buying, selling, and trading.

Thank you everyone.