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Growth and grazing on Prochlorococcus and Synechococcus by two marine ciliates
Author(s) -
Christaki Urania,
Jacquet Stéphan,
Dolan John R.,
Vaulot Daniel,
Rassoulzadegan Fereidoun
Publication year - 1999
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1999.44.1.0052
Subject(s) - prochlorococcus , synechococcus , ciliate , biology , cyanobacteria , autotroph , bacterioplankton , predation , ecology , botany , phytoplankton , nutrient , bacteria , genetics
The two most abundant marine autotrophic prokaryotes, Prochlorococcus and Synechococcus , often have different distributions in the ocean. For example, Synechococcus is restricted to the first 100 m, whereas Prochlorococcus extends much deeper in oligotrophic waters. This is in part explained by differences in adaptation to nutrient and light regimes. However, they could also be subjected to different predation rates. To explore this hypothesis, we compared the consumption of these two picoplankters by an algivorous ciliate, Strombidium sulcatum , and a bactivorous ciliate, Uronema sp. For both ciliate species, removal rates were higher, by a factor of 3 to 10, for Synechococcus compared to Prochlorococcus when prey items were presented alone or together. The growth of the two ciliates fed Synechococcus and/or Prochlorococcus also differed. S. sulcatum grew well on both prey items, whether alone or together, whereas Uronema sp. grew slowly when fed Synechococcus and very poorly when fed Prochlorococcus either alone or with Synechococcus . Our results suggest that Prochlorococcus may be less subject to ciliate predation than Synechococcus .