Science Screen Report for Kids- Tarantula - Up Close and Personal - Volume 17, Issue 5

From Volume 17 Issue 5. Theyre big, hairy, scary, poisonous and found in a variety of habitats on Earth. The 8-legged arachnid is a pet for some, pest for others and in Asia, a spicy, cooked, snack. This program uncovers the cultural myths and truths about the King of Spiders and the modern research being done using its venom. Tarantulas comprise a group of hairy and often very large spiders belonging mainly to the family Theraphosidae, of which approximately 900 species have been identified. Historically tarantulas were the bigger genera from the family Lycosidae (like Lycosa tarantula). The colonists of the Americas gave the name to the bigger spiders of the tropic-dwelling families Theraphosidae and Dipluridae (funnel-web tarantulas), and that usage has now supplanted the earlier European one. Some genera of tarantula hunt prey primarily in trees; others hunt on or near the ground. All tarantulas can produce silk—while arboreal species will typically reside in a silken "tube tent", terrestrial species will line their burrows with silk to stabilize the burrow wall and facilitate climbing up and down. Tarantulas mainly eat insects and other arthropods, using ambush as their primary method of prey capture. The biggest tarantulas can kill animals as large as lizards, mice, and birds. Tarantulas are found in tropical and desert regions around the world. Most tarantulas are harmless to humans, and some species are popular in the exotic pet trade. Some species, while not known to have ever produced human fatalities, have venom that can produce extreme discomfort over a period of several days. The name 'tarantula' comes from the town of Taranto in Southern Italy and was originally used for an unrelated species of European wolf spider. The name was borrowed to apply to the theraphosids when Europeans explored areas where these large spiders were common. In Africa, theraphosids are frequently referred to as "baboon spiders". Asian forms are known as "earth tigers" or "bird-eating spiders". Australians refer to their species as "barking spiders", "whistling spiders", or "bird-eating spiders". People in French-speaking areas may apply the general name "mygales" to theraphosid spiders. Like all arthropods, the tarantula is an invertebrate that relies on an exoskeleton for muscular support. A tarantulas body consists of two main parts, the prosoma or the cephalothorax (the former is most often used) and the abdomen or opisthosoma. The prosoma and opisthosoma are connected by the pedicle, or what is often called the pregenital somite. This waist-like connecting piece is actually part of the prosoma and allows the opisthosoma to move in a wide range of motion relative to the prosoma. Depending on the species, the body length of tarantulas ranges from 2.510 cm (14 inches), with 8- to 30-cm (3- to 12-inch) leg spans (their size when including their legs). Leg span is determined by measuring from the tip of the back leg to the tip of the front leg on the opposite side. The largest species of tarantula can weigh over 85 gms(3 ounces).The largest of all, the Goliath Birdeater (Theraphosa blondi) from Venezuela and Brazil, has been reported to have a weight of 150 gms (5.3 ounces) and a leg-span of up to 12 inches (30 cm), males being the longer and females greater in girth. http://www.ssrvideo.com/