National Geographic : 1996 Sep
Superspider "There are spiders of marvelous bigness ... bigger than a man's hand," marveled Spanish explorer Fernandez de Oviedo in 1535. He may have been describing the South American goliath birdeater, shown life-size in a cut away view. Resting beneath a tropical dry, forest, the female tarantula's huge body is sustained by four book lungs (color coded in blue), named for their slender folds. The lungs add oxygen to the blood, pumped by a long, primitive heart (magenta). The nervous system (yellow) is concentrated primarily in the leggy front segment; the rear is crowded with the digestive tract (green), egg sac (beige), and silk producing glands purplel THERAPHOSABLONDI;PAINTINGBYCHRISTOPHER A. KLEIN, NATIONALGEOGRAPHICARTIST ' Airborne defenses With aflick of a hind leg, tarantulas of the Western Hemi sphere defend them selves by launchingtiny hairs bristlingwith micro scopic barbs. Once imbedded in the attacker'sskin or eyes, the barbs cause a maddening itch that can persistfor months. Early warning system Sensitive to the slightest vibrationor wind, pivoting hairfollicles on the tarantu la'sfeet and lower legs alert it to approachingdanger. The message is vital:Although they have as many as eight eyes, tarantulashave very poor vision.