Metabolic adaptations of deep-sea benthic foraminifera to seasonally varying food input
1992; Inter-Research; Volume: 81; Linguagem: Inglês
10.3354/meps081051
ISSN1616-1599
Autores Tópico(s)Geology and Paleoclimatology Research
ResumoATP content and metabolic activity of benthic foraminifera were determined from deepsea sediments of the Norwegian-Greenland Sea.Metabolic activity was analysed by measurements of Electron Transport System (ETS] activity and heat production.This, combined with live observations, revealed 2 survival strategies.Ruperlina stabilis, an obligate suspension feeder, is adapted to conditions in which it receives a steady input of particles throughout the year, enabling it to maintain a relatively high ATP content (153 f 23 ng ATP ind.-l) with a reduced ATP turnover rate (0.008 S-').In contrast Cribrostomoides subglobosum, Pyrgo rotalaria and Rhabdammina abyssorum undergo large (up to 10-fold) fluctuations in seasonal values of ATP and heat production, but retain a high, relatively constant ATP turnover rate (i.e.seconds).Such a rapid turnover allows these foraminifera to take quick advantage of sudden nutrient inputs; this state of readiness, however, is maintained at the cost of the protoplasm, which benthic foraminifera are apparently capable of metabolizing in times of starvation.C. subglobosum and P rotalaria responded to several sedimentation events with an increase in ETS activ~ty; single cells sometimes showed extremely high ATP values (50-to 100-fold increase), reflecting an individual physiological response to food input to the deep-sea.
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