12 research outputs found
Morphological adaptation of a planktonic diatom to growth in Antarctic sea ice.
Chaetoceros dichaeta Ehrenberg is one of the
most important planktonic diatom species in the Southern
Ocean, making a significant contribution to the total biomass
in the region. Our observations on both field and
culture material have revealed the existence of a specialized
form of C. dichaeta adapted to living in sea ice. This
sea ice form differs from the planktonic form by the shape
and orientation of the setae and the aperture length between
sibling cells. Thus, the diameter of the chain is equivalent
to the apical axes of the cells and is accompanied by a two
order of magnitude decrease in minimal space requirement.
Here, we report for the first time on the extraordinary
overwintering strategy of a planktonic diatom in sea ice
facilitated by its rapid morphological adaptation to
changing environmental conditions. This morphological
plasticity enables it to thrive in the confined space of the
sea ice brine matrix and retain its numerical dominance in
recurrent growing seasons and has likely evolved to
optimally exploit the dynamic ecosystem of the seasonally
ice-covered seas of the Southern Ocean