Thrixopelma pruriens

Last updated

Peruvian green velvet tarantula
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Mygalomorphae
Family: Theraphosidae
Genus: Thrixopelma
T. pruriens
Binomial name
Thrixopelma pruriens
Schmidt, 1998 [1]

Thrixopelma pruriens, known as the Peruvian green velvet tarantula, [2] is a species of tarantula found in Chile in South America (not Peru). [1] [3]

Though docile, this species is rarely kept as a pet in part due to its tendency to fling urticating hairs with minimal provocation. [4]

In 2014, researchers at Yale University identified a toxin called Protoxin-I from the tarantula's venom that shows promise as a new painkiller drug. [5] The toxin reduces activity in an ion channel associated with inflammation and neuropathic pain, making it potentially suitable as a treatment for both normal pain and pathological pain syndromes. [6] [2]

Related Research Articles

Venom Toxin secreted by an animal

Venom is a type of poison, especially one secreted by an animal. Venom has evolved in a wide variety of animals, both predators and prey, and both vertebrates and invertebrates.

Mutillidae Family of wasps

The Mutillidae are a family of more than 7,000 species of wasps whose wingless females resemble large, hairy ants. Their common name velvet ant refers to their dense pile of hair, which most often is bright scarlet or orange, but may also be black, white, silver, or gold. Their bright colors serve as aposematic signals. They are known for their extremely painful stings,, and has resulted in the common name "cow killer" or "cow ant" being applied to the species Dasymutilla occidentalis. However, mutillids are not aggressive and sting only in defense. In addition, the actual toxicity of their venom is much lower than that of honey bees or harvester ants. Unlike true ants, they are solitary, and lack complex social systems.

Batrachotoxin Chemical compound

Batrachotoxin (BTX) is an extremely potent cardio- and neurotoxic steroidal alkaloid found in certain species of beetles, birds, and frogs. The name is from the Greek word βάτραχος, bátrachos, 'frog'. Structurally-related chemical compounds are often referred to collectively as batrachotoxins. It is an extremely poisonous alkaloid. In certain frogs, this alkaloid is present mostly on the skin. Such frogs are among those used for poisoning darts. Batrachotoxin binds to, and irreversibly opens, the sodium channels of nerve cells and prevents them from closing, resulting in paralysis and death. No antidote is known.

Schmidt sting pain index Pain scale for insect stings

The Schmidt sting pain index is a pain scale rating the relative pain caused by different hymenopteran stings. It is mainly the work of Justin O. Schmidt, an entomologist at the Carl Hayden Bee Research Center in Arizona, United States. Schmidt has published a number of papers on the subject, and claims to have been stung by the majority of stinging Hymenoptera.

<i>Mucuna pruriens</i> Species of flowering plant

Mucuna pruriens is a tropical legume native to Africa and tropical Asia and widely naturalized and cultivated. Its English common names include monkey tamarind, velvet bean, Bengal velvet bean, Florida velvet bean, Mauritius velvet bean, Yokohama velvet bean, cowage, cowitch, lacuna bean, and Lyon bean. The plant is notorious for the extreme itchiness it produces on contact, particularly with the young foliage and the seed pods. It also produces many medium-sized red swollen bumps along with the itching. It has agricultural and horticultural value and is used in herbalism.

Poneratoxin is a paralyzing neurotoxic peptide made by the bullet ant Paraponera clavata. It prevents inactivation of voltage gated sodium channels and therefore blocks the synaptic transmission in the central nervous system. Specifically, poneratoxin acts on voltage gated sodium channels in skeletal muscle fibers, causing paralysis, and nociceptive fibers, causing pain. It is rated as a 4 plus on the Schmidt sting pain index, the highest possible rating with that system, and its effects can cause waves of pain up to twelve hours after a single sting. Schmidt describes it as "pure, intense, brilliant walking over flaming charcoal with a three-inch nail embedded in your heel." It is additionally being studied for its uses in biological insecticides.

Buthidae Family of scorpions

The Buthidae are the largest family of scorpions, containing about 96 genera and over 1230 species as of 2021. A few very large genera are known, but a high number of species-poor or monotypic ones also exist. New taxa are being described at a rate of several new species per year. They occur in the warmer parts of every major landmass on Earth, except Antarctica and New Zealand. Together with four other families, the Buthidae make up the superfamily Buthoidea. The family was established by Carl Ludwig Koch in 1837.

Scorpion toxin

Scorpion toxins are proteins found in the venom of scorpions. Their toxic effect may be mammal- or insect-specific and acts by binding with varying degrees of specificity to members of the Voltage-gated ion channel superfamily; specifically, voltage-gated sodium channels, voltage-gated potassium channels, and Transient Receptor Potential (TRP) channels. The result of this action is to activate or inhibit the action of these channels in the nervous and cardiac organ systems. For instance, α-scorpion toxins MeuNaTxα-12 and MeuNaTxα-13 from Mesobuthus eupeus are neurotoxins that target voltage-gated Na+ channels (Navs), inhibiting fast inactivation. In vivo assays of MeuNaTxα-12 and MeuNaTxα-13 effects on mammalian and insect Navs show differential potency. These recombinants exhibit their preferential affinity for mammalian and insect Na+ channels at the α-like toxins' active site, site 3, in order to inactivate the cell membrane depolarization faster[6]. The varying sensitivity of different Navs to MeuNaTxα-12 and MeuNaTxα-13 may be dependent on the substitution of a conserved Valine residue for a Phenylalanine residue at position 1630 of the LD4:S3-S4 subunit or due to various changes in residues in the LD4:S5-S6 subunit of the Navs. Ultimately, these actions can serve the purpose of warding off predators by causing pain or to subdue predators.

Tarantula Family of spiders

Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae. Currently, 1,010 species have been identified. The term "tarantula" is usually used to describe members of the family Theraphosidae, although many other members of the same infraorder (Mygalomorphae) are commonly referred to as "tarantulas" or "false tarantulas". Some of the more common species have become popular in the exotic pet trade. Many New World species kept as pets have setae known as urticating hairs that can cause irritation to the skin, and in extreme cases, cause damage to the eyes.


Psalmotoxin (PcTx1) is a spider toxin from the venom of the Trinidad tarantula Psalmopoeus cambridgei. It selectively blocks Acid Sensing Ion Channel 1-a (ASIC1a), which is a proton-gated sodium channel.

Vanillotoxin Chemical compound

Vanillotoxins are neurotoxins found in the venom of the tarantula Psalmopoeus cambridgei. They act as agonists for the transient receptor potential cation channel subfamily V member 1 (TRPV1), activating the pain sensory system. VaTx1 and 2 also act as antagonists for the Kv2-type voltage-gated potassium channel (Kv2), inducing paralytic behavior in small animals.

Hanatoxin is a toxin found in the venom of the Grammostola spatulata tarantula. The toxin is mostly known for inhibiting the activation of voltage-gated potassium channels, most specifically Kv4.2 and Kv2.1, by raising its activation threshold.

Huwentoxins (HWTX) are a group of neurotoxic peptides found in the venom of the Chinese bird spider Haplopelma schmidti. The species was formerly known as Haplopelma huwenum, Ornithoctonus huwena and Selenocosmia huwena. While structural similarity can be found among several of these toxins, HWTX as a group possess high functional diversity.


Mambalgins are peptides found in the venom of the black mamba, an elapid snake. Mambalgins are members of the three-finger toxin (3FTx) protein family and have the characteristic three-finger protein fold. First reported by French researchers in 2012, mambalgins are unusual members of the 3FTx family in that they have the in vivo effect of causing analgesia without apparent toxicity. Their mechanism of action is potent inhibition of acid-sensing ion channels.

<i>Thrixopelma</i> Genus of spiders

Thrixopelma is a genus of South American tarantulas that was first described by Günter E. W. Schmidt in 1994.

RhTx is a small peptide toxin from Scolopendra subspinipes mutilans, also called the Chinese red-headed centipede. RhTx binds to the outer pore region of the temperature regulated TRPV1 ion channel, preferably in activated state, causing a downwards shift in the activation threshold temperature, which leads to the immediate onset of heat pain.

GTx1-15 is a toxin from the Chilean tarantula venom that acts as both a voltage-gated calcium channel blocker and a voltage-gated sodium channel blocker.

Protoxin-II, also known as ProTx-II, PT-II or β/ω-TRTX-Tp2a, is a neurotoxin that inhibits certain voltage-gated calcium and voltage-gated sodium channels. This toxin is a 30-residue disulfide-rich peptide that has unusually high affinity and selectivity toward the human Nav1.7. channel.


OdK2 is a toxin found in the venom of the Iranian scorpion Odonthobuthus doriae. It belongs to the α-KTx family, and selectively blocks the voltage-gated potassium channel Kv1.3 (KCNA3).

Protoxin-I, also known as ProTx-I, or Beta/omega-theraphotoxin-Tp1a, is a 35-amino-acid peptide neurotoxin extracted from the venom of the tarantula Thrixopelma pruriens. Protoxin-I belongs to the inhibitory cystine knot (ICK) family of peptide toxins, which have been known to potently inhibit voltage-gated ion channels. Protoxin-I selectively blocks low voltage threshold T-type calcium channels., voltage gated sodium channels and the nociceptor cation channel TRPA1. Due to its unique ability to bind to TRPA1, Protoxin-I has been implicated as a valuable pharmacological reagent with potential applications in clinical contexts with regards to pain and inflammation


  1. 1 2 "Taxon details Thrixopelma pruriens Schmidt, 1998". World Spider Catalog. Natural History Museum Bern. Retrieved 2016-04-29.
  2. 1 2 Gui, Junhong; Liu, Boyi; Cao, Guan; Lipchik, Andrew M.; Perez, Minervo; Dekan, Zoltan; Mobli, Mehdi; Daly, Norelle L.; Alewood, Paul F.; Parker, Laurie L.; King, Glenn F.; Zhou, Yufeng; Jordt, Sven-Eric & Nitabach, Michael N. (2014). "A Tarantula-Venom Peptide Antagonizes the TRPA1 Nociceptor Ion Channel by Binding to the S1–S4 Gating Domain". Current Biology. 24 (5): 473–483. doi:10.1016/j.cub.2014.01.013. PMC   3949122 . PMID   24530065.
  3. Schmidt, G. (2003). Die Vogelspinnen: Eine weltweite Übersicht. Hohenwarsleben: Neue Brehm-Bücherei. p. 191.
  4. "Thrixopelma-puriens-care-sheet". Retrieved 2014-03-19.
  5. Hathaway, Bill (2014-02-13). "YaleNews | Within tarantula venom, new hope for safe and novel painkillers found". Retrieved 2014-03-19.
  6. "The Peruvian Green Velvet Tarantula's Gift". The New York Times . 17 February 2014. Retrieved 19 March 2014.