Marine Cocconeis Ehrenberg (Bacillariophyceae) species and related taxa from Kerguelen's Land (Austral Ocean, Indian Sector)

Více o knize

Recent marine species of Cocconeis Ehrenberg and related taxa from sub-Antarctic Kerguelen Islands sediments were analyzed. The predominant macroalgae, particularly Macrocystis pyrifera and Durvillaea antarctica, favored epiphytism, allowing for a diverse proliferation of attached genera. Material collected during four austral summers between 1985 and 1992 led to the description of nearly 40 Cocconeis and related taxa, with several being new to these Austral localities, while others remain taxonomically uncertain. Diversity was notably high under the M. pyrifera canopy, with some species identified as epiphytes on larger diatoms and others as predominantly epipsammic. Taxa exhibited a wide range of dimensions and ornamentation variability. Communities varied by locality, influenced by tidal changes, macroalgal canopies, and mussel beds. While some Cocconeis species are ubiquitous, others appear to be endemic to these islands. Dominant species include Cocconeis scutellum and important components like C. fasciolata and C. stauroneiformis. Previous misidentifications and poor illustrations by earlier authors are clarified in this study. Scanning electron microscopy (SEM) was utilized for taxon illustration, with descriptions based on SEM and light microscopy provided where possible, emphasizing the uniqueness of the Austral diatom flora, particularly that of Kerguelen’s Land.