PRINCIPAL INVESTIGATOR (S ): Judith Miles 



EXPERIMENT TITLE/NUMBER : Web Formation, ED52 



PROGRAM/MISSION : Skylab 3 



CLASSIFICATION : Animal - Cross spider ( Araneous diadematus ) 



DISCIPLINE(S) : Behavioral science, Neurosensory 



OBJECTIVES : To compare the detailed structure of webs built by spiders in 

 null gravity with those built in a one-g environment to determine how 

 weightlessness affects the central nervous system. 



PROTOCOL : The crewmen deployed the spider cage and an automatic 16-mm 

 photography system, released the spider in the cage, took 35-mm photographs, 

 and obtained television coverage of the spiders and webs. 



EQUIPMENT : Spider cage, photographic equipment. 



RESULTS : Returned web samples showed finer threads were used in flight than 

 in ground-built webs. Anita's death was reported on the 51st day of the 

 mission and Arabella's death was discovered on return to earth. Both spiders 

 apparently died of dehydration and are preserved at the Smithsonian Institute. 



CONCLUSIONS : There is positive evidence that the spider utilized a 

 gravity-sensing organ to size her thread. 



PUBLICATIONS : 197, 377, 500 



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