|Title:||The impact of body size and starvation on the biochemistry and the physiology of ammonium excretion in the marine mysid, "Leptomysis lingvura"||Authors:||Fernández-Urruzola, Igor
Packard, Theodore T.
|UNESCO Clasification:||251001 Oceanografía biológica||Keywords:||Glutamate dehydrogenase
|Issue Date:||2011||Abstract:||Ammonium (NH4+) release by bacterial remineralization and heterotrophic grazers determines the regenerated fraction of phytoplankton productivity, so the measurement of NH4+ excretion in marine organisms is necessary to characterize both the magnitude and the efficiency of the nitrogen cycle. Glutamate dehydrogenase (GDH) is largely responsible for NH4+ formation in crustaceans and consequently should be useful in estimating NH4+ excretion by marine zooplankton.<br />Here, we address body size and starvation as sources of variability on the GDH to NH4+ excretion ratio (GDH/RNH4+). We found a strong correlation between the RNH4+ and the GDH activity (r2 = 0.87, n = 41) during growth. Since GDH activity maintained a linear relation (b = 0.93) and RNH4+ scaled exponentially (b =0.55) in well fed mysids, the GDH/RNH4+ ratio increased with size. However, the magnitude of its variation increased even more when adult mysids were starved. In this case, the GDH/RNH4+ ratio ranged from 11.23 to 102.41.||URI:||http://hdl.handle.net/10553/7221||Source:||5th International Zooplankton Symposium, Pucón, Chile, Marzo, 2011|
|Appears in Collections:||Póster de congreso|
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