Some aspects of trophic relations of gizzard shad, Dorosoma cepedianum

Foods, feeding, voidance, and bioenergetics of gizzard shad were investigated. Ten of the 17 most frequently occurring plankters in Smith Mountain Reservoir were utilized as food: the bulk of the diet consisted of Glenodinium, Dinobryon, and copepod nauplii. The feeding behavior of shad was described. Shad were observed to demonstrate the directed activity of seeking particulate materials from the substratum, It was concluded that shad are continuous feeders, but show seasonal variation in food intake. Evacuation of the alimentary tract required 18 to 21 hours and was related to continuous feeding, activity. Feeding trials with Artemia nauplii yielded the equation: n/T = 1.36 T⁰·²³ W⁰·⁴⁶ D⁰·⁰⁹. Filtration rates were shown to be inversely related to feeding duration and body size. Oxygen consumption was measured at three temperatures. Routine metabolism-weight relations were shown to be M = 0.452 W⁰·⁸⁴⁸ at 10 C, M = 0.659 W⁰·⁸⁴¹ at 15 C and M = 0.769 W⁰·⁹³⁷ at 20 C in a siphon-equipped respirometer. At 20 C this relationship was M = 0.627 W⁰·⁸¹³ in a flowing water system. A typical yearling gizzard shad, 34 g in weight, required a dietary equivalent of 1204 cal/day of which 905 cal were spent for respiratory metabolism.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Wildlife Biology

Department dc:contributor.department

Wildlife Biology

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1971

Author dc:creator

• Smith, Alphonso Oscar

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-10302008-120728

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/40273