Cyriocosmus aueri — the Peruvian Dwarf Redleg Tarantula — is one of the most visually striking dwarf tarantulas available in the hobby. Formally described by Kaderka in 2016 from specimens collected in Peru's Loreto region, this tiny terrestrial species is prized for its rich colouration — a dark brown-black body with a distinctive pale abdominal pattern and vivid reddish-orange leg markings that make it look far more impressive than its 1–1.5 inch adult size might suggest.
Unlike the Psalmopoeus species in our collection, C. aueri is beginner-friendly, possesses urticating hairs, and comes from a humid Peruvian rainforest environment that calls for consistently moist conditions. It is a species for collectors who appreciate the extraordinary in miniature.
QUICK ANSWER — WHAT DOES CYRIOCOSMUS AUERI NEED?
C. aueri requires a small terrestrial enclosure (minimum 6"W × 6"D × 4"H), temperatures of 75–82°F, high humidity of 75–85% RH, consistently moist substrate, appropriately tiny prey, and a secure escape-proof lid. It is a beginner-friendly species. Adults reach only 1–1.5 inches — all prey and equipment must be sized accordingly.
- Enclosure: Small terrestrial, escape-proof lid essential, 6" minimum width
- Temperature: 75–82°F (24–28°C) daytime
- Humidity: 75–85% RH — keep substrate consistently moist
- Feeding: Every 7 days (adults); every 3–4 days (slings) with appropriately tiny prey
- Experience level: Beginner friendly
- Urticating hairs: Yes (Type III) — New World species
- Adult size: 1–1.5 inches DLS — true dwarf tarantula
Species Overview & Natural Habitat
Cyriocosmus aueri was formally described in 2016 from the Loreto region of northeastern Peru — a vast area of lowland Amazonian rainforest characterised by consistently high temperatures, extreme humidity, and year-round rainfall. In the wild, C. aueri lives at ground level, sheltering in leaf litter, under bark, and in shallow burrows in the forest floor. It is a microhabitat specialist adapted to the warm, perpetually humid conditions of the Peruvian Amazon.
The genus Cyriocosmus contains some of the most visually striking dwarf tarantulas in the entire family Theraphosidae. Despite their tiny stature — adults rarely exceed 1.5 inches in diagonal leg span — many species display exceptional colouration. C. aueri is particularly prized for the vivid reddish-orange leg markings that contrast sharply with its dark body and pale abdominal chevron pattern.
Described by Kaderka in 2016, this is a relatively recently documented species. Captive-bred specimens are increasingly available as hobbyist breeders work with the genus, but quality captive-bred stock remains in demand due to the species' visual appeal and compact size.
Is Cyriocosmus aueri Right for You?
BEGINNER FRIENDLY — WITH SOME IMPORTANT NOTES
C. aueri is genuinely accessible for first-time and newer keepers. It has urticating hairs, mild venom, and a generally docile disposition. However, its very small size creates specific challenges: escape-proof enclosures are critical, prey must be tiny, and the humid care requirements are non-negotiable. These are manageable with preparation but worth understanding before acquiring.
C. aueri is an excellent choice if you: are a newer keeper wanting a visually striking but manageable species, have existing experience with humidity management, appreciate the extraordinary in miniature, and understand the escape-proofing requirements of a very small spider.
Consider carefully if you: have young children or pets with unsupervised access to the enclosure (escape risk), struggle with humidity maintenance, or find very small spiders difficult to observe and work with.
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View Cyriocosmus aueri — Shop Now →What Enclosure Does Cyriocosmus aueri Need?
C. aueri is a ground-dwelling terrestrial species. Unlike the arboreal Psalmopoeus in our collection, it needs floor space over height — and because of its tiny size, even a "small" enclosure gives it ample room to explore and web. The most critical enclosure requirement is an escape-proof lid. A missing sling or juvenile of this species is nearly impossible to locate.
| Stage | Minimum enclosure | Notes |
|---|---|---|
| Sling (under 0.5") | 1–2 oz deli cup | Secure lid essential; tiny ventilation holes only |
| Juvenile (0.5–0.75") | 3"W × 3"D × 3"H | Cork hide at substrate level; moist substrate |
| Sub-adult (0.75–1") | 4"W × 4"D × 3"H | Begin adult husbandry protocol |
| Adult (1–1.5") | 6"W × 6"D × 4"H | Escape-proof lid; deep moist substrate |
How to Set Up a Cyriocosmus aueri Enclosure (Step by Step)
- Add 3–4 inches of moist substrate — coconut fibre, organic topsoil, or peat/coco mix. Keep substrate consistently moist throughout — think damp sponge, not dripping wet.
- Place a small cork tube or curved cork flat at substrate level as a hide. This species will web extensively around its retreat and burrow beneath it.
- Add a tiny water dish — a bottle cap or the lid of a small deli cup. Change weekly.
- Verify the lid is completely escape-proof. Check every gap, ventilation hole, and seal. A sling under 0.5" can escape through surprisingly small gaps.
- Keep lighting minimal. C. aueri is shy and cryptic — significantly more active in dim conditions.
- Allow 24 hours to settle before offering prey.
Temperature & Humidity Requirements for Cyriocosmus aueri
C. aueri comes from Peru's Loreto region — one of the most consistently humid environments on earth. High humidity is not optional. A consistently moist substrate is the single most important husbandry parameter to maintain.
| Parameter | Ideal | Acceptable | Avoid |
|---|---|---|---|
| Daytime temperature | 75–82°F (24–28°C) | 72–84°F | Below 68°F / above 86°F |
| Night temperature | 70–76°F (21–24°C) | 68–78°F | Sustained below 65°F |
| Ambient humidity | 75–85% RH | 70–88% RH | Consistently below 65% |
| Substrate | Consistently moist | Lightly moist | Dry or bone dry — dysecdysis risk |
| Misting frequency | Full enclosure every 5–7 days | When substrate begins to lighten | Allowing full dry-out between mistings |
How to Feed Cyriocosmus aueri
Prey sizing is critical for dwarf tarantulas. Standard hobby feeder sizes — even "small" crickets — are far too large for most C. aueri. Always use the smallest available prey items and pre-kill for slings and juveniles.
| Stage | Prey item | Frequency |
|---|---|---|
| Sling (under 0.5") | Fruit flies (D. melanogaster), micro crickets prekilled | Every 3–4 days |
| Juvenile | Fruit flies, tiny crickets prekilled | Every 4–5 days |
| Sub-adult | Small crickets, micro dubia (prekill recommended) | Every 5–6 days |
| Adult | Small crickets, small dubia roaches | Every 7 days |
| Pre-molt / Post-molt | None — remove all prey | Resume 7–10 days post-molt |
PREY REMOVAL — CRITICAL FOR DWARF SPECIES
Remove all uneaten prey within 24 hours. Crickets will readily attack a molting or recently molted dwarf tarantula — a single oversized cricket can kill a C. aueri during its vulnerable post-molt window. Pre-killing prey eliminates this risk for slings and juveniles.
Sling Care — The Most Critical Stage
C. aueri slings are extremely small — typically under 0.5" when acquired. They require the same care as adults but in miniature: tiny enclosures with escape-proof lids, fruit flies or micro crickets, and consistently moist conditions. The sling stage is when humidity failures are most dangerous — a dry enclosure can cause a failed molt and death within days at this size.
Molting — What to Expect
Pre-molt signs: prey refusal for 1–3 weeks, abdomen darkening, increased webbing and burrowing, sealing behaviour.
During molt: Typically 15–60 minutes — significantly faster than larger species. Do not disturb. Maintaining correct humidity during this period is critical.
Post-molt: Wait 7–10 days before offering food. Start with smaller prey than normal.
Handling & Temperament
C. aueri is generally docile. It has urticating hairs (Type III) and mild venom — not a high-risk species. However, handling is not recommended given the significant drop and escape risk with such a tiny spider. Appreciate it as the display animal it is.
Common Health Problems
| Issue | Signs | Action |
|---|---|---|
| Dysecdysis | Stuck shed, limbs trapped | Raise humidity immediately; moist hide |
| Dehydration | Shrunken abdomen; lethargy | Mist entire enclosure; check water dish |
| Prey injury | Wounds; missing legs | Pre-kill prey for slings; remove within 24 hours |
| Substrate mites | Tiny specks in substrate | Full enclosure clean; avoid overwatering |
| Escape | Spider missing | Prevention only — check lid seals every maintenance |
Frequently Asked Questions About Cyriocosmus aueri
How big does Cyriocosmus aueri get?
Adults reach only 1–1.5 inches DLS — a true dwarf tarantula. Despite the small size, the vivid colouration is clearly visible and makes it one of the most rewarding dwarf species to keep.
Is Cyriocosmus aueri good for beginners?
Yes, with preparation. The main considerations are escape-proofing, correct humidity, and appropriate prey sizing. The species is docile and low-risk compared to Old World species.
Why does Cyriocosmus aueri need such high humidity?
It originates from Peru's Loreto region — Amazonian rainforest with consistently extreme humidity. Low humidity causes dehydration and dysecdysis (failed molts), which is particularly dangerous for small species.
What do I feed such a tiny tarantula?
Fruit flies for slings, progressing to micro crickets and small crickets for adults. Standard hobby feeder crickets are far too large for most life stages.
How do I know if my C. aueri is in pre-molt?
Prey refusal, darkening abdomen, and increased burrowing and webbing. Molts are fast — sometimes you'll find an exuvia before you realised it had started.
Is Cyriocosmus aueri legal in the US?
Legal in most US states with no CITES restrictions. Always verify local regulations before acquiring.
Field Life Pets · Captive Bred · Ships Lower 48
Big personality. Tiny price. Extraordinary colour.
Every C. aueri we sell is captive bred, established on feeders, and one of the most visually striking dwarf tarantulas you can own. Just $15. Ships to all lower 48 states — live arrival guaranteed.
Get Your Cyriocosmus aueri — $15 →Written by FLPD · Updated June 2026. For informational use only. Verify local legality before acquiring any exotic tarantula.