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Document Type

Article

Publication Date

1967

Keywords

Pike--Minnesota; Fishes--Spawning; Fishes--Development; Plankton populations

Abstract

In this study, certain physical, chemical and biological conditions were observed in order to relate them to the development and survival of eggs and young northern pike in a small pond. The spawning period lasted one week and was interrupted by unfavorable weather. Low temperature caused the eggs to develop at a rate slower than the rate other workers have shown to be normal. Many eggs between stages II and Ill appeared to be developing abnormally and were perhaps reacting to an unsuitable environmental condition. Since 90% of all eggs completed development, neither slow nor abnormal development increased the egg mortality rate. The young pike fed selectively on Cladocera rather than other types of plankton present and did not utilize small rotifers as food. Scarcity of plankton appears to have been the major factor restricting northern pike production. Growth rates of pike on different sides of the pond correspond directly to the distribution of plankton. When plankton was not abundant, growth was slow, the quantity of food per stomach was low, and many fish had not fed. It is possible that most young pike died because they were attacked or eaten by other pike, but a low density of plankton shortly after hatching apparently triggered the outbreak of cannibalism.

First Page

101

Last Page

109

Primo Type

Article

Included in

Zoology Commons

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