Original paper

Revision of the main freshwater species of Achnanthales (Bacillariophyta) from sub-antarctic Iles Kerguelen

Le Cohu, Par René


A revision of the genera formerly included within Achnanthes was made from samples of different water-bodies of Kerguelen Archipelago. Twenty four species belonging to the genera Achnanthes, Achnanthidium, Planothidium and Psammothidium were described using light and electron microscopy. Three nomenclatural combinations are proposed: Planothidium australe, Psammothidium aretasii and Psammothidium incognitum var. stauroneioides. Psammothidium daonense and Psammothidium reversum are recorded for the first time in Kerguelen Archipelago. Psammothidium therezienii is the only species which can be considered as endemic to Subantarctica. Five taxa are cosmopolitan. Six taxa are confined to antarctic and subantarctic zones whereas seven other taxa are also reported from South America.