Coexistence of two Cyclotella diatom species in the plankton of Lake Baikal. (2nd July 2015)

• Record Type: Journal Article
• Authors: Jewson, David H.; Granin, Nick G.; Gnatovsky, Ruslan Yu.; Lowry, Steve F.; Teubner, Katrin
• Is Part Of: Freshwater biology. Volume 60:Number 10(2015:Oct.)
• Page Start: 2113
• Page End: 2126
• Publication Date: 2015-07-02
• Subjects: Freshwater biology -- Periodicals; Biologie d'eau douce -- Périodiques; 577.605
• DOI: 10.1111/fwb.12636
• Languages: English
• ISSNs: 0046-5070

Abstract

<abstract abstract-type="main" id="fwb12636-abs-0001"> <title>Summary</title> <p> <list id="fwb12636-list-0001" list-type="order"> <list-item> <p>In a combined laboratory and field study over 10 years, we investigated how two centric diatom species, <italic>Cyclotella baicalensis</italic> and <italic>Cyclotella minuta</italic>, have coexisted in the plankton of Lake Baikal in Siberia for over 100, 000 years.</p> </list-item> <list-item> <p>The species differ substantially in cell size: <italic>C. baicalensis</italic> has some of the largest cells found in freshwater phytoplankton at up to 135 μm diameter, but <italic>C. minuta</italic> can be as small as 10 μm. They illustrate the advantages and disadvantages of small versus large size in a planktonic environment. Other differences included a faster division rate of <italic>C. minuta</italic> but a faster rate of biovolume increase in <italic>C. baicalensis</italic>.</p> </list-item> <list-item> <p>Timing of their life cycles and peak cell abundances differed. <italic>C. baicalensis</italic> peaked in June or July after ice break‐up, but <italic>C. minuta</italic> usually peaked in autumn, because it was able to tolerate higher temperatures and survive higher in the water column during summer stratification, allowing growth to begin earlier than other species.</p> </list-item> <list-item> <p>Satellite‐derived surface temperature data combined with temperature tolerances of each species revealed how variation in upwelling affected population development.</p> </list-item> <list-item> <p>Speciation may have occurred after a change in environmental conditions allowed larger cells to remain in suspension throughout the year. Long‐term co‐existence became possible because ecological differences reduced interspecific competition.</p> </list-item> </list> </p> </abstract>