1/6 Vernacular Name GOLIATH BIRD EATING SPIDER PHYLUM / SUBPHYLUM Arthropoda CLASS / ORDER / SUBORDER Arachnida / Araneae / Orthognatha FAMILY Theraphosidae GENUS/SPECIES Theraphosa blondi GEOGRAPHIC RANGE Surinam, Brazil, Guyana and Venezuela HABITAT Swamps and marshes in interior of northern tropical rainforests of South America TOURING HIGHLIGHTS - Until recently, the Goliath was believed to be the world's largest species of spider. A male of the species has the longest documented leg span of 12” across, about the size of a dinner plate or small pizza. A two-year-old female Goliath Tarantula bred by Robert Bustard had a leg span of 11” and weighed 6 oz in February 1998. In general, males are slimmer but somewhat longer-legged, while females are considerably heavier and more thickly built. However, Theraphosa apophysis, the pinkfoot goliath tarantula, does have some specimens recorded at 13-inch leg spans. - There is no documented case of the death of a human being resulting from the bite of a Goliath Bird Eating Spider, or any other tarantula. Their toxins have evolved to kill or immobilize their prey, not to ward off human beings. - Although the Goliath is large and powerful enough to eat frogs, small lizards and small mammals, the name bird eater is somewhat of a misnomer. They can and do take hatchlings and occasionally may be able to snare a small unaware bird incubating eggs, but bird hunting is enough of a rarity to make it an exaggeration to consider them as dedicated bird hunters. Goliaths can take snakes and one was observed taking a Fer-de-lance, a pit-viper with an extremely lethal bite. The Goliath Bird Eater was named by explorers from the Victorian era who first reported them to the western world, and witnessed on eating a humming bird. - They have the ability to make noise. When feeling threatened, they are capable of making a loud hissing noise by rubbing bristles on their legs together. Called stridulation, it can be Goliath Bird Eating Spider 2/6 loud enough to be heard up to a distance of 15 feet. - Like all spiders, Goliath Bird Eating Spiders use their fangs for subduing their prey. They carry it to their dens (or to a safe location) for devouring at leisure. They don't have teeth for tearing and chewing their meals so they regurgitate digestive juices onto their victim. These digestive juices break down the soft tissues so that the spider can siphon up its meal via the suction action of its stomach. All that's left when the spider has finished are bones, skin, fur and/or feathers. - Hair covers the entire body of the Goliath, as it does on all tarantulas; hair is their most important means of sensory input, and serves several functions. Some hairs contain temperature or smell receptors. Other hairs can detect airborne vibration. Hairs in certain areas, mostly on the abdomen, can act as an itchy irritant to potential predators, and the Goliath is notorious for its ability to throw these from its abdomen. This ability, coupled with its size and aggressiveness, sharply limits its popularity in the pet market. Those intrepid souls who insist on keeping Goliaths are warned not to handle them because the result can be painful and dangerous if there is an allergic reaction to these hairs or they strike the eyes, mouth or nose. - The infra-order of Mygalomorphs, which includes all tarantulas, is relatively primitive. One key difference from true spiders (suborder Labidognatha) is found in the placement of the chelicerae and subsequent jaw action. The first pair of limbs (not legs), the chelicerae, are sharp and pointed and used for capturing prey, then paralyzing it by injecting a poison. On their ventral surfaces each chelicerae is armed with a venomous fang fed by ducts leading from a pair of poison glands. The fangs, in their relaxed state, fold next to a row of spikes or teeth. In true spiders they are attached below the head and are used in a lateral motion affording them a relatively greater biting span than is seen in the mygalomorphs. In the latter the chelicerae are located on the front of the head forcing them to strike forward and downward. - A second distinction between mygalomorphs and true spiders is the respiratory system. The respiratory system of the mygalomorphs differs from that of true spiders in having two sets of book lungs and no trachea in contrast to the true spiders, which have one pair of book lungs and trachea. Book lungs are air-filled sacs with a series of leaf-like folds of the body wall held apart by supports that allow air to circulate between them. The openings to the book lungs can be discerned as slits at the rear of the pale regions. The spaces within the folds are filled with blood and communicate with blood sinuses of the abdomen. Trachea are branching air-filled channels opening through small pores on the abdomen that bring air to the tissues. The combination of a single pair of book lungs and the possession of trachea provide a more efficient respiratory system for the true spiders compared to that of the mygalomorphs. SURVIVAL STATUS AND / OR CONSERVATION - Not currently listed as threatened, but habitat destruction, particularly the loss of tropical rainforest may constitute a threat in the future. ENEMIES AND / OR DEFENSE - Enemies include predatory mammals, spider eating birds, snakes and humans. - In addition to running, they can defend themselves aggressively and deliver a bite with their poisonous fangs. They may assume a threat posture by rearing up on the back two pairs of legs. In this position the spider extends its front two pairs of legs and palpi vertically into the Goliath Bird Eating Spider 3/6 air. Under continued provocation the spider will lunge forward periodically and may deliver a painful bite to its antagonist. - They are capable of throwing urticating hairs (hairs that cause a painful or itching reaction) from their abdomens at an attacker. - None of these defenses work against one of the most relentless and formidable of their enemies, the Pompiliid wasps commonly called in the vernacular tarantula hawk-wasps. Females of these large wasps seek out large spiders on which to lay their eggs. Tarantulas up to and including the Goliath Bird Eating Spider have no defense against this predator. Once a wasp has located a tarantula it lures it from its burrow or forces its way into the burrow and delivers a paralyzing sting through one of the spider’s flexible membranes (e.g. a leg joint). The paralyzed spider is then entombed within its own burrow or one dug in advance by the wasp. The wasp deposits a single egg on the immobilized spider and seals the burrow with soil. On hatching, the wasp maggot proceeds to devour the still living spider, which eventually dies. The fully developed maggot then pupates and emerges from the burrow as a large, metallic tarantula hawk-wasp. - There are also parasitic flies that have maggots that burrow into the spider and feed internally. Prior to pupation they burst out of the spider’s abdomen killing it in the process. Some mite species are also tarantula parasites. These tend to be white in color and attach themselves to membranous regions on the spider’s external surface. Unlike the other parasites these do not usually lead to the death of a tarantula unless the tarantula is weakened by secondary factors. PHYSICAL - Color ranges from dark to light brown. - The body is made up of two distinct parts; the cephalothorax, or head and neck combined, and the abdomen. The most obvious part of the front portion is the carapace. This is a shield- like plate that covers the dorsal region of the cephalothorax. - Their eyesight is weak even though they have eight eyes and are able to see only variations in the level of light. They rely much more heavily on sensory hairs that feel the slightest vibrations on the ground and in the air, allowing them to detect movement. - The pedipalps look like small legs but are sensory and their expanded bases help to hold and squeeze the prey. In mature males the pedipalps are modified for transferring sperm to the female. The four pairs of walking legs are armed at their ends with curved claws. - The abdomen is not segmented and has no appendages except for spinnerets, of which there are typically 3 pairs. The spinnerets are fingerlike organs that have minute spinning tubes at their tips, sometimes numbering a hundred or more on each spinneret, that exude fluid silk. Silk is a protein that polymerizes under tension and hardens into thread as it is stretched. Some of these tubes excrete not silk but a sticky fluid that causes certain threads of the web to become adhesive. LONGEVITY - In wild: Unknown. - In captivity: Requires about 10 years to mature to adults. Males live for only three to six years upon maturing, while the life expectancy for a female Goliath is up to 30 years with an average of 12 to 14 years more likely. The spiders continue to molt after reaching maturity and are able to re-grow any limbs they might lose. Because the females can molt throughout their adult lives it is believed that females of very large species like the Goliath bird eater Goliath Bird Eating Spider 4/6 may be able to live up to fifty years, but this has not been proven. ACTIVITY PERIOD - Nocturnal DIET AND FEEDING - In wild: Goliaths primarily eat insects and other invertebrates but do take larger prey such as bird nestlings, frogs, lizards and small snakes, including poisonous ones.