PRINCIPAL INVESTIGATOR(S ): Herbert W. Scheld, Anwar A. Baky, John F. Boyd, 



Victor B. Eichler, P. M. Fuller, Ronald B. 

 Hoffman, J. R. Keefe, K. P. Kuehnow, J. M. 

 Oppenheiraer, Gloria A. Salinas, and R. J. 

 von Baumgarten 



EXPERIMENT TITLE/NUMBER : Killifish Hatching and Orientation, MA-161 



PROGRAM/MISSION : Apollo-Soyuz Test Project 



CLASSIFICATION : Animal - Killifish (Fundulus heteroclitus) 



DISCIPLINE(S) : Cell biology, Behavioral science, Neurosensory 



OBJECTIVES : To evaluate the hazards inherent in the exposure of living 

 organisms to the space environment during critical portions of the life cycles 

 or for extended periods. The points of primary emphasis were the function and 

 development of the vestibular system and calcium deposition, particularly as 

 it relates to otolith development. 



PROTOCOL : The experiment package consisted of two parts: A series of staged 

 embryos in five individual compartments of a polyethylene bag and a series of 

 preconditioned juvenile fish in a similar bag. Embryos at 32, 66, 128, 216, 

 and 336 hours were used. Development occurred at a constant temperature of 

 295-K. Experiment packages were mounted on the Docking Module wall and 

 photographed periodically during the mission. At splashdown, vestibular 

 sensitivity was tested in a rotating, striped drum. Subsequently, additional 

 vestibular orientation tests were performed. Some of the killifish were fixed 

 for microscopic examination. 



EQUIPMENT : Transport control package, experimental package, rotating striped 

 drum, photography equipment. 



RESULTS : Postflight tests with rotating striped drum, light orientation, 

 geotaxis, parabolic trajectory on fry, hatchlings, mature (R+0.5 yr) were not 

 significantly different. Inflight visual conditioning was not significant. 

 Juvenile fish exhibited looping swimming activity. Hatchlings from 336 hr egg 

 stage also looped. Normal vestibular behavior was suggested by MD-9. No 

 growth abnormalities were observed in embryos that developed inflight. Normal 

 diving response resumed by R+0 . Juvenile swimming patterns indicated abnormal 

 swim bladders. 



CONCLUSIONS : There appeared to be no significant effect of space flight on 

 vestibular senses and embryonic development. 



PUBLICATIONS : 470, 471 



132 



