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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS1992

Preliminary results of the Artemia salina experiments in biostack on LDEF

The mosaic egg of the brine shrimp, Artemia salina, resting in blastula or gastrula state represents a system that during further development, proceeds without any further development to the larval stage, the free swimming nauplius. Therefore, injury to a single cell of the egg will be manifest in the larvae. In several experiments, it was shown that the passage of a single heavy ion through the shrimp egg damaged a cellular area large enough to disturb either embryogenesis or further development of the larvae, or the integrity of the adult individual. Emergence from the egg shell was heavily disturbed by the heavy ions as was hatching. Additional late effects, due to a hit by a heavy ion, are delayed of growth and of sexual maturity, and reduced fertility. Anomalies in the body and the extremities could be observed more frequently for the nauplii which had developed from eggs hit by heavy ions.

Graul, E. H.↗
NASA NTRS1995

Effect of microgravity and hypergravity on embryo axis alignment during postencystment embryogenesis in Artemia franciscana (Anostraca)

Cysts of brine shrimp attached with a liquid adhesive to 12-mm diameter glass coverslips in a syringe-type fluid processing apparatus were flown aboard the NASA space shuttle Discovery, flight STS-60, from 3-11 February 1994, and were allowed to undergo postencystment embryogenesis and to hatch in microgravity. The shuttle flight and the ground-based control coverslips with attached cysts were parallel to the earth's surface during incubation in salt water. Based on the position of the cyst shell crack in the attached cyst population, the ground-control nauplii emerged mostly upward. On the shuttle in microgravity, although our method of detection of orientation would not reveal emergence toward the coverslip, the ratio of the position of the cyst shell crack in the population after hatching best fit the predicted values of a random direction for nauplii emergence. Centrifugation on earth was then used to create hypergravity forces of up to 73 g during postencystment embryogenesis and hatching. The upward orientation of emerging nauplii showed a high degree of correlation (r(2) =98.8%) with a linear relationship to the log of g, with 78.2% of the total hatching upward at 1 g and 91.0% hatching upward at 73 g.

NASA Program NSCORT↗