[1] Acad Sci Czech Republ, Inst Hydrobiol, Ceske Budejovice, Czech Republic
[2] Univ S Bohemia, Fac Biol Sci, Ceske Budejovice, Czech Republic
[3] Natl Ctr Marine Res, Inst Oceanog, Athens 19013, Greece
[4] Netherlands Inst Sea Res, Dept Biol Oceanog, NL-1790 AB Den Burg, Netherlands
[5] UPMC, UMR CNRS 7093, Lab Oceanog Villefranche, Marine Microbial Ecol Grp, F-06234 Villefranche Sur Mer, France