Life history allocation of energy to growth and reproduction was determined for female gizzard shad. Absolute caloric energy allocated to eggs increased with age. The relative amount of production energy directed to reproduction increased with age up to 5 years and then decreased. Seasonal variation in lipids was studied. Quantitative changes occurred in ovarian lipids during the reproductive cycle. Carcass lipids varied seasonally. Age of sexual maturity was 3 years. Delayed maturity is attributed to high allocation of energy to growth enabling shad to outgrow intense competition and predation in pre-reproductive ages; there is little competition and predation in reproductive shad. Growth rates and condition factors indicated constant availability of food seasonally.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc504310 |
| Date | 12 1900 |
| Creators | Fagan, Joseph A. |
| Contributors | Fitzpatrick, Lloyd C., Pearson, William D., Stanford, Jack Arthur, 1947-, Beitinger, Thomas L. |
| Publisher | North Texas State University |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | vii, 62 leaves: ill., maps, Text |
| Coverage | United States - Texas |
| Rights | Public, Fagan, Joseph A., Copyright, Copyright is held by the author, unless otherwise noted. All rights reserved. |
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