Marine derived dinoflagellates in Antarctic saline lakes: Community composition and annual dynamics

TY - JOUR

T1 -  Marine derived dinoflagellates in Antarctic saline lakes: Community composition and annual dynamics

AU - Rengefors, K.

AU - Layborn-Parry, L.

AU - Logares, R.

AU - Marshall, W.A.

AU - Hansen, Gert

N1 - KEYWORDS Antarctica • cold-water dinoflagellates • dinoflagellate dynamics • polar • Polarella glacialis • saline lakes • Scrippsiella hangoei

PY - 2008

Y1 - 2008

N2 - The saline lakes of the Vestfold Hills in Antarctica offer a remarkable natural laboratory where the adaptation of planktonic protists to a range of evolving physiochemical conditions can be investigated. This study illustrates how an ancestral marine community has undergone radical simplification leaving a small number of well-adapted species. Our objective was to investigate the species composition and annual dynamics of dinoflagellate communities in three saline Antarctic lakes. We observed that dinoflagellates occur year-round despite extremely low PAR during the southern winter, which suggests significant mixotrophic or heterotrophic activity. Only a small number of dominant dinoflagellate species were found in each lake, in contrast to the species-rich Southern Ocean from which the lake communities are believed to be derived. We verified that the lake species were representatives of the marine polar dinoflagellate community, and not freshwater species. Polarella glacialis Montresor, Procaccini et Stoecker, a bipolar marine species, was for the first time described in a lake habitat and was an important phototrophic component in the higher salinity lakes. In the brackish lakes, we found a new sibling species to the brackish-water species Scrippsiella hangoei (J. Schiller) J. Larsen, previously observed only in the Baltic Sea.

AB - The saline lakes of the Vestfold Hills in Antarctica offer a remarkable natural laboratory where the adaptation of planktonic protists to a range of evolving physiochemical conditions can be investigated. This study illustrates how an ancestral marine community has undergone radical simplification leaving a small number of well-adapted species. Our objective was to investigate the species composition and annual dynamics of dinoflagellate communities in three saline Antarctic lakes. We observed that dinoflagellates occur year-round despite extremely low PAR during the southern winter, which suggests significant mixotrophic or heterotrophic activity. Only a small number of dominant dinoflagellate species were found in each lake, in contrast to the species-rich Southern Ocean from which the lake communities are believed to be derived. We verified that the lake species were representatives of the marine polar dinoflagellate community, and not freshwater species. Polarella glacialis Montresor, Procaccini et Stoecker, a bipolar marine species, was for the first time described in a lake habitat and was an important phototrophic component in the higher salinity lakes. In the brackish lakes, we found a new sibling species to the brackish-water species Scrippsiella hangoei (J. Schiller) J. Larsen, previously observed only in the Baltic Sea.

KW - Faculty of Science

U2 - 10.1111/j.1529-8817.2008.00517.x

DO - 10.1111/j.1529-8817.2008.00517.x

M3 - Journal article

C2 - 27041419

SN - 0022-3646

VL - 44

SP - 592

EP - 604

JO - Journal of Phycology

JF - Journal of Phycology

IS - 3

ER -