Date of Award

1941

Degree Type

Thesis

Degree Name

Master of Science in Zoology

Department

Zoology

First Advisor

Charles J. Fisk

Abstract

A steadily decreasing yield in the winter flounder stock has led to a series of investigations into its life history by the Federal Fish and Wildlife Service, in an attempt to ascertain the cause of its decline. Disagreement in age determination by scale analysis has been responsible for much delay in solving an urgent problem. To devise an accurate method for determining age by scale reading, a series of specimens of gradually increasing sizes, beginning with those known to be of the currently-spawned stock, were selected and their scales subjected to detailed study.

Results showed that age can definitely be determined by scale analysis when accompanied by essential supplementary data on length and date of capture. Age determination of 509 specimens from the population of Point Judith Pond checked with the findings of ear-bone readings of age.

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