Goliath birdeater tarantula, scientific name Theraphosa blondi, is the biggest known spider in the world. It belongs to the family Theraphosidae. In total, there are about 900 species of tarantula. A goliath birdeater weighs about 120 grams, with the leg span measuring up to 30 cms (12 inches). In general, the female is larger than the male. It is also known as the goliath birdeater, birdeater, or bird eating spider. The name 'birdeater' was assigned in the Victorian era, when explorers saw a tarantula of the same species eating a hummingbird.
This spider is light to dark-brown in color, usually with markings on the leg portion. Its body and legs are covered with hair that can be either short or long. Since it belongs to arthropods, it possess only an exoskeleton. The body is divided into two parts - the cephalothorax and the abdomen. The former part consists of the eyes, legs (eight in number), and excretory system, whereas the abdomen part hosts the brain, spinnerets, heart, reproductive organs, and excretory system that continues from the cephalothorax. In case of a female, the egg sac is located in the abdomen part.
This spider is a native to the rainforests of South America. It is a deep burrower and is mostly found in wet, damp, and marshy areas. It has poor eyesight and is nocturnal.
Like other tarantulas, the goliath birdeater is a carnivore. It ambushes its prey with the help of its fangs. However, in spite of the name birdeater, it does not eat birds. Instead, it feeds on a wide range of vertebrates and invertebrates like mice, frogs, lizards, small snakes, beetles, spiders, crickets, moths, and mealworms.
Both the male and female attain maturity in about 3 years. It is likely that the female eats the male after mating. The male lacks tibial spurs that are present in the first pair of legs in many tarantula species. These tibial spurs are used as a means of protection from the female during mating. After mating, the female lays about 200-400 eggs that hatch within two months. She looks after the spiderlings; the young ones leave the mother after a few weeks and start living on their own. The lifespan of a male birdeater is about 6 years, while the female can live up to 14 years.
This spider is quite aggressive; on being threatened, it makes a hissing noise (stridulation) by rubbing the leg bristles together. It protects itself by the means of its fangs (1-2.5 cm) and urticating hair. Though its fangs are venomous, they are comparatively less toxic than other deadly insects. Its bite causes mild pain and at times, swelling, like that of a wasp sting.
However, what one should be more careful of is the urticating hair that the spider flickers when it is under threat. Studies have found that this hair causes irritation of the skin and lungs. Due to these irritating hair, this spider is not a preferred pet, as it is with other tarantula species. Some indigenous people regard the goliath birdeater dish as a delicious recipe. This is the reason why the population of this mighty spider is decreasing day-by-day.