Toxicity Classification System: What Determines "Danger"?
Before purchasing a tarantula or scorpion, you first need to understand how experts measure "toxicity strength." The standard that professionals use is the concept of medical significance — this refers to the level at which "a sting or bite could cause serious harm to life or function without medical intervention." The key distinction is not simply "the presence of venom," but rather "whether hospitalization is necessary" becomes the axis of judgment.
Tarantula toxicity is easier to understand when viewed as a spectrum. While most species possess venom glands, the medical impact on humans is comparable to or less than a bee sting. However, some Old World species (originating from Africa, Asia, and the Middle East) contain neurotoxic components, and cases have been reported where symptoms persist or systemic reactions occur. For individuals with allergies, even species with mild venom carry an anaphylaxis risk, so this too falls under the category of "medically significant."
Scorpion toxicity is often organized on a 5-point scale. Levels 1-2 involve only localized pain with natural recovery. Level 3 produces systemic symptoms (sweating, muscle spasms) but a healthy adult can recover. Levels 4-5 are powerful ion-channel-disrupting neurotoxins that can cause respiratory paralysis and cardiac arrest if untreated. Among all scorpions, approximately 30 to 50 species are considered medically significant, with the remaining 2,500+ species posing relatively low risk.
Safe Species for Beginners: What Specifically to Choose
Tarantulas
- Chilean Rose (Grammostola rosea / G. porteri)：A New World species from South America. Toxicity is extremely low with few bite incidents reported. Movements are slow and temperament is docile. However, they may fast for extended periods (several months to a year), and it is important not to misinterpret "not eating" as a sign of illness.
- Brazilian Black (Grammostola pulchra)：A New World species of the same genus. Characterized by striking solid-black coloration and calm temperament. Growth is slow and availability is limited, but if obtained, it is ideal for beginners. Its toxicity spectrum is equivalent to the Chilean Rose.
- Azurescens (Aphonopelma chalcodes / A. seemanni)：Originating from North and Central America. Easy to manage in dry conditions with no medical significance. Tends to use urticating hairs (irritating hairs) as a defense mechanism more than biting.
What these three species have in common is "New World origin + low metabolism + defense mechanism primarily based on urticating hairs rather than biting." Urticating hairs cause itching when they contact skin or eyes, but this is separate from toxicity risk and can be managed with hand washing and eye protection after handling.
Scorpions
- Emperor Scorpion (Pandinus imperator)：Originating from West Africa. Though large at 15-20 cm in length, toxicity is low with pain comparable to a honeybee sting. Ranks at toxicity levels 1-2. It is the most commonly kept pet scorpion, and since it is listed in CITES Appendix II, confirm that any individual was obtained through legitimate channels.
- Asian Forest Scorpion (Heterometrus genus)：Originating from Southeast Asia. Similar to the Emperor with low toxicity, ranking at level 2. Prefers humid environments and adapts well to Japan's climate. However, individuals often have more aggressive temperaments than Emperors, and handling is not recommended.
Dangerous Species You Must Never Keep
Note that all of the dangerous scorpion species listed below belong to the Buthidae family and are fundamentally prohibited from being kept or imported in Japan as designated alien species. Before even considering the danger they pose, it is important to understand that these species are legally forbidden to keep.
Scorpions
- Androctonus genus：Originating from North Africa and the Middle East. Toxicity level 5. Neurotoxins (such as chlorotoxin) act on the cardiac and respiratory muscles, with high fatality rates if untreated. A. australis (the yellow scorpion) is considered one of the most dangerous scorpions in the world.
- Leiurus quinquestriatus (Death Stalker)：Originating from the Middle East and North Africa. Toxicity level 5. Has one of the lowest LD50 values among scorpions (minimal venom is lethal), and is particularly dangerous for children, elderly individuals, and immunocompromised persons. Though rare in Japan's distribution channels, it can still be obtained through overseas online retailers — exercise caution.
- Parabuthus and Tityus genera：Include species from Africa and South America with toxicity levels 4-5. Verify the toxicity classification at the genus level before purchase.
Tarantulas
- OBT (Orange Baboon Tarantula / Pterinochilus murinus)：An Old World species from Africa. Extremely aggressive with numerous bite incidents reported. Bites can result in severe localized pain, muscle spasms, and swelling lasting several days. Even experienced keepers must handle this species with extreme caution.
- Poecilotheria genus：Originating from India and Sri Lanka. Among Old World species, it has the highest recorded bite incidents, with reports of prolonged muscle spasms and systemic malaise. Popular due to its striking appearance, but completely unsuitable for beginners.
- Widow Spider genus (Latrodectus：including the black widow and red-backed spider)：Possesses α-latrotoxin with medical significance. In Japan, this is designated as a specified alien species and keeping is prohibited. These are not actually relatives of tarantulas and have separate distribution channels.
Pre-Purchase Risk Assessment Checklist
Before deciding to make a purchase, confirm the following five items. If any answer is "no," it is strongly recommended to reconsider the purchase or switch to a safer species.
- Origin Verification：Confirm whether the species is New World (North and South America) or Old World (Africa, Asia, Middle East). Old World species generally have higher toxicity and rely more on biting since they lack urticating hairs.
- Genus-Level Toxicity Classification Verification：Reference toxicity data from specialist websites (The Scorpion Files, Theraphosidae.com, etc.) using the common and scientific names. Use literature-based information rather than relying on impressions of "seeming safe."
- Japan's Legal Status Verification：Check whether the species is designated as a specified alien species, specified animal, or listed in CITES appendices (details below).
- Emergency Access Verification：Is there a hospital within 30 minutes of your home capable of emergency response? If keeping highly toxic species, create a list of medical facilities that provide 24-hour care.
- Seller Credibility Verification：Are the scientific name, origin, hatch date, and captive history disclosed? Shops selling only by common Japanese names without detailed information are considered to have insufficient disclosure.
Japan's Legal Framework: Three Laws to Understand Before Keeping
When keeping tarantulas or scorpions in Japan, you must understand the following legal framework.
Invasive Species Act (Designated Alien Species)：All species in the Buthidae family (including Androctonus, Death Stalker, and other highly venomous species) are designated as specified alien species, with keeping, importing, and transferring fundamentally prohibited. Among spiders, funnel-web spiders (genera Atrax and Hadronyche), widow spiders (Latrodectus), and some swift spiders are also designated. Conversely, Emperor Scorpions, Asian Forest Scorpions, and the major tarantula species in circulation are not designated. Since lists are reviewed periodically, check the Ministry of the Environment's latest information.
Animal Welfare and Management Law (Specified Animals)：The scope of specified animals covers only mammals, birds, and reptiles; invertebrates such as scorpions and tarantulas are not subject to this classification. Regulation of dangerous invertebrate keeping falls under the Invasive Species Act mentioned above. If uncertain, check with your prefecture's animal welfare office or Ministry of the Environment materials before purchase.
Convention on International Trade in Endangered Species (CITES)：Pandinus imperator (Emperor Scorpion) is listed in CITES Appendix II, and domestic sale of individuals without proper import permits is illegal. When purchasing, request documentation (CITES certificate or equivalent). Cheap individuals without documentation may be smuggled.
Initial Response Protocol if Stung or Bitten
First: Identify What Stung or Bit You
Keep the scientific name of the species you keep written down beforehand. It affects treatment protocols in emergency care.
If Symptoms Are Localized Only (pain, swelling, redness limited to bite site)
→ Wash with running water → Cool → Observe for 30 minutes to 1 hour. If symptoms do not worsen, can be monitored at home. However, for Old World tarantulas or scorpions with toxicity level 3 or higher, consider medical consultation as a precaution.
Seek Emergency Care Immediately if Any of the Following Symptoms Appear
- Difficulty breathing or sensation of throat tightness
- Systemic muscle spasms or sensation of paralysis
- Excessive sweating, salivation, or pupil changes (autonomic nervous system symptoms)
- Drop in blood pressure or altered consciousness
- Any non-dermal symptoms in individuals with allergy history
Information to Provide When Contacting the Hospital
- Species name (scientific name) and origin
- Time of sting or bite
- Current symptoms and rate of progression
- Allergy history and current medications
In Japan, only a limited number of hospitals maintain antivenom for poisonous snakes and venomous organisms. If keeping species with toxicity levels 4-5 such as Androctonus or Leiurus, it is recommended to contact nearby hospitals in advance. The Japan Poison Information Center (072-727-2499) operates 24/7 and can be used for symptom consultation and hospital referrals.
