|Steady-State Energetics of a Planktonic Herbivore|
Droop, M.R.; Scott, J.M. (1978). Steady-State Energetics of a Planktonic Herbivore. J. Mar. Biol. Ass. U.K. 58(3): 749-772
In: Journal of the Marine Biological Association of the United Kingdom. Cambridge University Press/Marine Biological Association of the United Kingdom: Cambridge. ISSN 0025-3154, more
Energy budget; Growth; Respiration; Brachionus plicatilis Müller, 1786 [WoRMS]; Marine
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The marine rotifer Brachionus plicatilis Muller was grown bacteria-free in a chemostat with the alga Brachiomonas submarina, labelled with SUP-57 Co vitamin B SUB-12 , as the limiting nutrient. State variables were recorded at a number of steady states between zero dilution rate and washout. These were algal input biomass, algal (and faecal) output biomass, rotifer (and gut) output biomass, in terms of carbon, nitrogen and vitamin B SUB-12 ; and input and output dissolved vitamin B SUB-12 . From these were calculated input, ingestion, assimilation, excretion and growth rates and the associated transfer efficiencies. Ingestion and assimilation efficiencies were high and not obviously growth rate dependent, whereas the growth efficiency was interpreted as ranging from zero at zero growth rate to a maximum at half maximal growth and back to zero at washout, being the result of the carbon and nitrogen excretion rates, which, finite at zero growth rate, increased with increasing rapidity with increasing growth rate, tending to infinity as the maximum growth rate was approached. Nitrogen and carbon excretion rates were correlated. 'Slow-adapted' and 'fast-adapted' modes of growth were recognized with characteristically different growth and energy parameters. The resons for and implications of these findings are discussed.