''Grammostola iheringi'' also known as the Entre Rios tarantula, it was first described by Keyserling in 1891. They are found in

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

, and is considered the biggest tarantula in the ''

Grammostola ''Grammostola'' is a genus of South American Theraphosidae, tarantulas that was first described in text by Eugène Simon, Eugène Louis Simon in 1892. These medium- to large-sized spiders are native to tropical South America, and are usually brown ...

'' genus.

Description

Females can live a bit over 20 years, and can grow to up to 23cm. They are leggier than most others in the ''Grammostola'' genus, and also differs from them by their behavior. They have velvety black legs, which have a slight blue tint. And a black

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

, which is bordered by an orange coloration. The

opisthosoma The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma (cephalothorax). It is a distinctive feature of the subphylum Chelicerata (arachnids, horseshoe crabs and others). Although it is similar in most respects to a ...

is a dark red color. GiTx1

Venom

As most New World Tarantulas, this species lacks potent venom. Although their

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

has been analyzed, and the

toxin A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849– ...

Gitx1 was found. The effects of this toxin in mice ranges from rotating movements, disorientation and paralysis, to complete paralysis and death. Depending on the amount of the toxin inserted. The venom name comes from the initials of this species and toxin, plus the x from toxin.

Behavior

Compared to the others in the ''Grammostola'' genus, this species is an outlier. They are quite an active tarantula, and a bit defensive. It is usually out in the open, though they are quite skittish. They also present a stalking tactic for hunting, which differs from the more typical ambush strategy.

References

{{Taxonbar, from=Q2741175 Theraphosidae Spiders of Brazil Spiders described in 1891