title: Water quality management for low temperature marine fishes in space.
abstract: Vestibular Function Experiment Unit (VFEU), one of the Spacelab facility flown in Neurolab mission (STS-90) in April, 1998, was to support neurophysiological research using a marine fish, Opsanus tau (oyster toadfish). The functions of the VFEU were primarily a quality management of environmental water during the mission at 14 degrees C and for acquiring physiological signals from implanted micro-electrodes in the otolith nerves as well as the spatial acceleration of the fish. A key element of the life support system was a balanced biological filter containing two types of nitrifying bacteria, Nitrosomonas for ammonia oxidization and Nitrobacter for nitrite oxidization. Although the 16 days mission was successful, two toadfishes died in late phase of the mission. Ammonium concentration in those two life support systems elevated to remarkably high level at the end of the mission whereas the other two indicated very low. This report summarizes the results of the water quality management of the VFEU during the Neurolab mission based on analysis of water samples taken during the flight and those taken prior and just after the flight.
authors.affiliation: Department of Physiology, Fujita Health University School of Health Sciences, Toyoake, Japan. nagaokas@fujita-hu.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Nagaoka
authors.forename: S
authors.initials: S
authors.lastname: Matsubara
authors.forename: M
authors.initials: M
authors.lastname: Kato
authors.forename: S
authors.initials: S
authors.lastname: Uchida
authors.forename: M
authors.initials: M
authors.lastname: Uemura
authors.forename: T
authors.initials: T
authors.lastname: Sakimura
authors.forename: N
authors.initials: N
authors.lastname: Ogawa
authors.forename: H K
authors.initials: HK
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D017756:Aquaculture; D001835:Body Weight; D005374:Filtration / Q000379:methods; D005399:Fishes / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D008021:Life Support Systems / Q000295:instrumentation*; D009573:Nitrites / Q000378:metabolism; D009576:Nitrobacter / Q000378:metabolism; D009606:Nitrosomonas / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000032:analysis / Q000378:metabolism; D012623:Seawater; D013026:Space Flight / Q000295:instrumentation*; D013696:Temperature; D018508:Water Purification / Q000379:methods*; D014893:Weightlessness
chemical_list: D009573:Nitrites; D000644:Quaternary Ammonium Compounds