Tarantula

Tarantulas comprise a group of large and often hairy spiders belonging to the family Theraphosidae. There are currently about 1,000 species that 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. New World species kept as pets have urticating hairs that can cause irritation to the skin and, in extreme cases, cause damage to the eyes. Like all arthropods, the tarantula is an invertebrate that relies on an exoskeleton for muscular support. Like other Arachnida, a tarantula’s body comprises two main parts, the prosoma (or cephalothorax) and the opisthosoma (or abdomen). The prosoma and opisthosoma are connected by the pedicel, or pregenital somite. This waist-like connecting piece is actually part of the prosoma and gives the opisthosoma a wide range of motion relative to the prosoma. Tarantula sizes range from as small as a fingernail to as large as a dinner plate when the legs are fully extended. Depending on the species, the body length of tarantulas ranges from 2.5 to 10 cm (1 to 4 in), with leg spans of 8–30-centimetre (3–12 in). Leg span is determined by measuring from the tip of the back leg to the tip of the front leg on the opposite side. Some of the largest species of tarantula may weigh over 85 g (3 oz); the largest of all, the goliath birdeater (Theraphosa blondi) from Venezuela and Brazil, has been reported to attain a weight of 170 g (6.0 oz) and a leg-span up to 30 cm (12 in), males being longer and females greater in girth. The fang size of this tarantula reaches a maximum of 3.8 cm (1.5 in). Theraphosa apophysis (the pinkfoot goliath) was described 187 years after the goliath birdeater, so its characteristics are not as well attested.Theraphosa blondi is generally thought to be the heaviest tarantula, and T. apophysis to have the greatest leg span. Two other species, Lasiodora parahybana (the Brazilian salmon birdeater) and Lasiodora klugi, rival the size of the two goliath spiders. Most species of North American tarantulas are brown. Elsewhere, species have been found that variously display cobalt blue (Cyriopagopus lividus), black with white stripes (Aphonopelma seemanni), yellow leg markings (Eupalaestrus campestratus), metallic blue legs with vibrant orange abdomen and green prosoma (Chromatopelma cyaneopubescens). Their natural habitats include savanna, grasslands such as the pampas, rainforests, deserts, scrubland, mountains, and cloud forests. They are generally classed among the terrestrial types. They are burrowers that live in the ground.