Respiratory gas exchange, nitrogenous waste excretion, and fuel usage during starvation in juvenile rainbow trout, Oncorhynchus mykiss

R. F. Lauff, C. M. Wood

Research output: Contribution to journalArticle

86 Citations (Scopus)

Abstract

Oxygen consumption, CO2 excretion, and nitrogenous waste excretion (75% ammonia-N and 25% urea-N) were measured daily in 4-g rainbow trout over a 15-day starvation period. Oxygen consumption and CO2 excretion declined while N excretion increased transiently in the mid-part of the starvation period but was unchanged from control levels at the end. Component losses (as percentage of total fuel used) of protein, lipid, and carbohydrate were 66.5, 31.1, and 2.4% respectively, as measured from changes in body weight and body composition, the latter relative to a control group at day 0. Instantaneous fuel use, as calculated from the respiratory quotients and nitrogen quotients, indicated that relative protein use rose during starvation, but contributed at most 24% of the aerobic fuel (as carbon). Lipid metabolism fell from about 68 to 37%, and was largely replaced by carbohydrate metabolism which rose from 20 to 37%. We conclude that the two approaches measure different processes, and that the instantaneous method is preferred for physiological studies. The compositional method is influence by greater error, and measures the fuels depleted, not necessarily burned, because of possible interconversion and excretion of fuels.

Original languageEnglish
Pages (from-to)542-551
Number of pages10
JournalJournal of Comparative Physiology B
Volume165
Issue number7
DOIs
StatePublished - Jan 1 1996

Fingerprint

pulmonary gas exchange
respiratory gases
Oncorhynchus mykiss
Starvation
gas exchange
starvation
excretion
rainbow
Gases
Oxygen Consumption
Body Weight Changes
oxygen consumption
Process Assessment (Health Care)
Carbohydrate Metabolism
carbohydrate
Body Composition
Lipid Metabolism
Ammonia
Rosa
metabolism

Keywords

  • Fuel
  • Nitrogen quotient
  • Rainbow trout, Oncorhynchus
  • Respiratory quotient
  • Starvation

ASJC Scopus subject areas

  • Physiology (medical)
  • Environmental Science(all)
  • Physiology
  • Animal Science and Zoology

Cite this

Respiratory gas exchange, nitrogenous waste excretion, and fuel usage during starvation in juvenile rainbow trout, Oncorhynchus mykiss. / Lauff, R. F.; Wood, C. M.

In: Journal of Comparative Physiology B, Vol. 165, No. 7, 01.01.1996, p. 542-551.

Research output: Contribution to journalArticle

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