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The Goliath birdeater (Theraphosa blondi) is a spider belonging to the tarantula family, Theraphosidae. It is considered to be the second largest spider in the world (by leg-span, it is second to the giant huntsman spider), and it may be the largest by mass. It is also called the Goliath bird-eating spider; the practice of calling Theraphosids "bird-eating" derives from an early 18th-century copper engraving by Maria Sybilla Merian that shows one eating a hummingbird, but the term is inaccurate as they do not primarily prey on birds.
Habitat and ecology
Theraphosa blondi is native to the upland rain forest regions of northern South America: Surinam, Guyana, northern Brazil and southern Venezuela. Goliath birdeaters are terrestrial, living in deep burrows, and are found commonly in marshy or swampy areas. It is a nocturnal species.
Females always mate[clarification needed] and sometimes end up eating their mates. Females mature in 3 to 4 years and have an average life span of 15 to 25 years. Males die soon after maturity and have a lifespan of 3 to 6 years. Colors range from dark to light brown with faint markings on the legs. Birdeaters have hair on their bodies, abdomens, and legs. The female lays anywhere from 100 to 200 eggs, which hatch into spiderlings within two months.
These spiders can have a leg span of up to 28 cm (11 in) and can weigh over 170 g (6.0 oz). Birdeaters are one of the few tarantula species that lack tibial spurs, located on the first pair of legs of most adult males.
In response to threats, Goliath birdeaters stridulate by rubbing setae on their pedipalps and legs. Also when threatened, they rub their abdomen with their hind legs and release hairs that are a severe irritant to the skin and mucous membranes. These urticating hairs can be harmful to humans, and the species is considered by some to have the most harmful tarantula urticating hair of all.
Like all tarantulas, T. blondi have fangs large enough to break the skin of a human (1.9–3.8 cm or 0.75–1.5 in). They carry venom in their fangs and have been known to bite when threatened, but the venom is relatively harmless and its effects are comparable to those of a wasp's sting. Tarantulas generally bite humans only in self-defense, and these bites do not always result in envenomation (known as a "dry bite").
Despite its name, the Goliath birdeater does not normally eat birds. As with other tarantulas, their diet consists primarily of insects. However, because of its size and opportunistic predatory behavior, it is not uncommon for this species to kill and consume a variety of small terrestrial vertebrates. In the wild, T. blondi has been observed feeding on rodents, frogs and toads, lizards, and snakes.
In captivity, the Goliath birdeater's staple diet should consist of cockroaches (generally the Dubia cockroach, Blaptica dubia). Spiderlings and juveniles can be fed crickets or cockroaches that do not exceed the body length of the individual. Feeding of mice is discouraged because of the risk of injury to the tarantula. It has previously been suggested that excess calcium from the feeding of rodents can cause problems during molting.
- World's biggest spider face-off - see which bug wins here[dead link]
- Herzig, Volker; King, Glenn F. (2013). "The Neurotoxic Mode of Action of Venoms from the Spider Family Theraphosidae". In Nentwig, Wolfgang. Spider Ecophysiology. p. 203. ISBN 3642339891.
- Striffler, Boris F. (November 2005). "Life history of Goliath Birdeaters – Theraphosa apophysis and Theraphosa blondi (Araneae, Theraphosidae, Theraphosinae)". Journal of the British Tarantula Society 21 (1). Retrieved 10 September 2013.
- "Largest Spider". Guinness World Records. Retrieved 24 August 2013.
- Perez-Miles, Fernando; Montes de Oca, Laura; Postiglioni, Rodrigo; Costa, Fernando G. (December 2005). "The stridulatory setae of Acanthoscurria suina (Araneae, Theraphosidae) and their possible role in sexual communication: an experimental approach". Iheringia, Serie Zoologia 95 (4). doi:10.1590/S0073-47212005000400004.
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