''Psalmopoeus cambridgei'', the Trinidad chevron tarantula, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

spider Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

in the family

Theraphosidae Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae. , 1,040 species have been identified, with 156 genera. The term "tarantula" is usually used to describe members of the family Theraphosidae, although m ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Trinidad Trinidad is the larger and more populous of the two major islands of Trinidad and Tobago. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is often referred to as the southernmos ...

. Its venom is the source of

psalmotoxin 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. Sources Psalmotoxin is a toxin produ ...

and

vanillotoxin Vanillotoxins (VaTxs, subtypes VaTx1, VaTx2, and VaTx3) 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), activati ...

which are classified as

inhibitor cystine knot An inhibitor cystine knot (aka ICK or Knottin) is a protein structural motif containing three disulfide bridges. Knottins are one of three folds in the cystine knot motif; the other closely related knots are the Growth Factor Cystine Knot (GFCK) ...

proteins. Psalmotoxin may be of

therapeutic A therapy or medical treatment (often abbreviated tx, Tx, or Tx) is the attempted remediation of a health problem, usually following a medical diagnosis. As a rule, each therapy has indications and contraindications. There are many different ...

use in patients with a

stroke A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...

Description

Trinidad chevron tarantula c Steve Laycock

The female has

chevron Chevron (often relating to V-shaped patterns) may refer to: Science and technology * Chevron (aerospace), sawtooth patterns on some jet engines * Chevron (anatomy), a bone * '' Eulithis testata'', a moth * Chevron (geology), a fold in rock ...

-shaped dark markings on the abdomen and her color varies through shades of green and brown with characteristic red or orange flashes on the legs. The mature male is

sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

, colored a more uniform grey or brown, the body appearing smaller in comparison to the diagonal leg span, reaching five inches (12 cm) on average. Males can reach maturity in as little as one year. The female is very large and fast-growing, reaching seven inches (18 cm) in leg span. It feeds readily and makes an attractive display animal, being fairly active when given correct housing conditions.Giantspiders.com
Retrieved June 27, 2011. Spiderlings of this species are very opportunistic and will usually create a home in a small crevice hidden with a silken blanket covered in soil.

Biology

Arboreal tarantulas live singly in specially constructed silken tube webs or in crevices, behind loose bark or among

epiphytic An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...

plants.Natural history of tarantula spiders
(

PDF Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. ...

) Retrieved June 27, 2011. The Trinidad chevron tarantula hunts

bat Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most bi ...

frog A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

grasshopper Grasshoppers are a group of insects belonging to the suborder Caelifera. They are among what is possibly the most ancient living group of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grasshopp ...

mice A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

cricket Cricket is a bat-and-ball game played between two teams of eleven players on a field at the centre of which is a pitch with a wicket at each end, each comprising two bails balanced on three stumps. The batting side scores runs by striki ...

s, and other

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s. The Trinidad chevron tarantula breeds freely in captivity. Two silken egg sacs are commonly produced from one mating and each of these contains one hundred to one hundred and fifty eggs. The female spider guards the sac, turning it occasionally, and the eggs hatch after about six weeks. The spiderlings usually disperse at the first

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...

stage.

Etymology

The name ''cambridgei'' is in honour of the

arachnologist Arachnology is the scientific study of arachnids, which comprise spiders and related invertebrates such as scorpions, pseudoscorpions, and harvestmen. Those who study spiders and other arachnids are arachnologists. More narrowly, the study of sp ...

Frederick Octavius Pickard-Cambridge Frederick Octavius Pickard-Cambridge (3 November 1860 – 9 February 1905) was an English arachnologist. He is sometimes confused with his uncle, Octavius Pickard-Cambridge (1828–1917), who was also an arachnologist and from whom F. O. Pi ...

References

{{Taxonbar, from=Q1039211 Theraphosidae Endemic fauna of Trinidad and Tobago Spiders of the Caribbean Spiders described in 1895