Catumiri

Catumiri (often misspelled “Catumuri”) is a genus of small South American tarantulas in the family Theraphosidae. It was established in 2004 by Brazilian arachnologist José Paulo Leite Guadanucci, who recognised that several dwarf “ischnocoline” tarantulas formed a distinct group based on their anatomy. The genus name comes from the Indigenous Tupi word catumiri, meaning “very small” – a nod to their tiny adult size compared to most tarantulas.

Historically, what we now call Catumiri argentinense was originally described in 1941 under a different genus, later treated as part of Oligoxystre. In his 2004 revision, Guadanucci moved this species into his new genus Catumiri and described three new species at the same time: C. chicaoi, C. petropolium (the type species), and C. uruguayense, all small-bodied tarantulas from Brazil and Uruguay.

Subsequent taxonomic work has refined the group. Modern catalogues now recognize five species spread across Brazil, Uruguay, Argentina and Chile: C. argentinense, C. chicaoi, C. parvum, C. petropolium and C. sapucai. In this updated view, C. uruguayense is treated as a synonym of C. parvum.

In the hobby, Catumiri are known as New World dwarf tarantulas, with adults typically reaching only around 2–2.5″ (5–6.5 cm) leg span, often with subtle bronze or copper tones (especially C. argentinense, the “Argentine Copper/ Bronze Dwarf”). They’re generally described as shy, fossorial or semi-fossorial spiders that build small burrows and webbed retreats, making them an appealing “tiny terrestrial” genus for keepers who enjoy discreet, small-bodied species.

Catumuri parvum

• Common name: Uruguayan Copper Dwarf Tarantula (Catumiri parvum)

• Origin: Southern South America – mainly Uruguay and southern Brazil

• Lifestyle: Terrestrial, burrowing dwarf; builds small burrows and webbed retreats close to the ground

• Adult size: About 2.5–4 cm (1–1.5") body length, roughly 2.5–3" legspan

• Growth rate: Moderate for a dwarf New World species; reaches adulthood in a few years with good care

• Temperament: Shy, reclusive, and generally calm; prefers to retreat rather than show defensive behavior

• Color & appearance: Subtle coppery-brown tones with a warm copper carapace, darker brown abdomen, and fine lighter leg hairs that give a soft, frosted look

Species history

Catumiri parvum has been known to science for well over a century. It was first described in 1878 by Eugen von Keyserling from specimens collected in Uruguay, originally under the name Ischnocolus parvus. Over time, the species was moved between a few early tarantula genera before finally being placed in the modern dwarf genus Catumiri, created by J. P. L. Guadanucci in 2004.

For a period, Uruguayan populations were split out as a separate species, Catumiri uruguayense, but later taxonomic work synonymized that name back into C. parvum, uniting these spiders under a single species again. Recent research has refined the diagnosis of the genus and expanded the known range of C. parvum within southern Brazil and Uruguay, highlighting it as a small but important piece of South America’s grassland tarantula fauna.

Natural habitat

In the wild, Catumiri parvum is found in southern South America, primarily Uruguay and southern Brazil, especially in the state of Rio Grande do Sul and nearby regions. Its type locality is in Lavalleja, Uruguay (Águas Blancas), an area of rolling hills and rocky outcrops within temperate grasslands.

This species is a terrestrial dwarf that lives close to the ground in open grasslands and subtropical plains. It makes use of small burrows, cracks in the soil, or spaces under stones, often lining these retreats with silk. Hobbyist and field notes describe it as a shy, reclusive spider that spends much of its time hidden, emerging mainly at night to hunt among low vegetation in relatively mild, seasonally humid conditions.

Our Specimen

Given name: TBD

Sex: TBD

Life stage: Sling

• New addition to our collection