Date Awarded

1972

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Virginia Institute of Marine Science

Advisor

Jackson Davis

Committee Member

Mark E. Chittenden

Committee Member

George Grant

Committee Member

William E. Odum

Abstract

Energy transformations and budget are computers for young-of-the-year blueback herring, Alosa aestivalis, in the James River, Virginia. Distribution, growth, and selective feeding are described. Fish and zooplankton collections were made at five stations in the main channel of the James RIver from June through November 1969. Two 24hr series of samples were collected in July and October 1968 in the Potomac River. A direct relationship existed between standing cropos of zooplankton and distribution, growth, and feeding of blueback herring. Zooplankton densities were highest upstream, where food consumption and growth rates were correspondingly highest. A progressive downstream decrease and upstream increase in the fish abundance occurred during teh study. Condition 9K) decreased after flooding from hurricane Camille. Blueback herring fed primarily on copepods (Eurytemora affinis, Cyclops vernalis, and Canthocamptus roberteokeri), but cladocerans (Bosmina longirostris-coregoni and Diaphanosoma brachyurum) were also important. Selection (electivity) was strongest for adult copepods and weakest for copepod nauplii. Selection for copepodites and B. longirostris-coregoni was moderate to weak. Feeding occurred only during daylight. Effect of predation on zooplankton populations is discussed. Respiration experiments were carried out in the laboratory from Nobvemer 1970 to March 1971. The regression of oxygen consumption on temperature (routine metabolism) was expressed as Log 0 = -1.4451 + 0.0548 T, where 0 = oxygen consumption (mg 02/gram wet weight/hr), and T = temperature (C). This dissertation is from the Joint Program Degree from the College of William & Mary and University of Virginia and awarded by the University of Virginia.

DOI

https://doi.org/10.25773/8YFP-0829

Rights

© The Author

Share

COinS