Program Studies on the Fundamental Effects of Radiation upon
Aquatic Animals
During the fiscal year of 1953-1954 work in other areas
and in field-work planning necessitated the curtailment of
a portion of this program.
However, progress was made in
completing the work initiated in previous years and on current
projects.
A.
Biological effects of X-rays on invertebrates
The major current research deals with the lethal effects
of X-rays upon the embryological development of the fresh-
water snail, Helisoma.
Documentary photomicrographs recording
development of irradiated and control egg masses were reviewed
and the results summarized for tabulation.
Further irradia-
tion experiments were conducted in an effort to reduce variability or experimental error.
Eggs undergoing the
first
cleavage were stained in order to relate the mitotic phases
to certain characteristic stages in the microscopic appearance
of the cleaving egg.
During the summer a report of this
experiment will be ready for publication.
Early this fiscal year installation was completed on
the beryllium-window X-ray unit, which expedited both radiobiological and roentgenographic experiments.
Incidental to
this activity a paper '©) on the radiography of small fishes for
meristic studies was published in August 1953.