The genus Pinnularia (Bacillariophyta) on Ile Amsterdam (TAAF, Southern Indian Ocean)

Bart van de Vijver (1) , Barbosa Chattova (2) , Ditmar Metzeltin , Marc Lebouvier (3)

1 Department of Bryophyta and Thallophyta - National Botanic Garden of Belgium
2 SCI / MUNI - Department of Botany and Zoology [Brno]
3 ECOBIO - Ecosystèmes, biodiversité, évolution [Rennes]

Ile Amsterdam (77° 34′ E, 37° 47′ S), a young, small volcanic island situated in the southern Indian Ocean has a very isolated geographic position and is one of the remotest places in the world. The geographic and physical features of the island have resulted in the presence of a very typical diatom (Bacillariophyta) fl ora dominated by species belonging to the genus Pinnularia. A total of 22 different Pinnularia taxa were observed during a taxonomic analysis of aquatic, moss and soil samples. Twelve taxa did not correspond to any of the currently known species and are described as new species. The new taxa are morphologically and ecologically characterized comparing each of them with all at present known species. The other Pinnularia species are briefl y discussed. A comparison with the other sub-Antarctic islands in the southern Indian Ocean clearly demonstrated the unique fl oristic situation of Ile Amsterdam.

Mots clés: Diatoms; Ile Amsterdam; new species; Pinnularia; sub-Antarctica

Domaines: Biodiversité et Ecologie

Bart van de Vijver, Barbosa Chattova, Ditmar Metzeltin, Marc Lebouvier. The genus Pinnularia (Bacillariophyta) on Ile Amsterdam (TAAF, Southern Indian Ocean). Nova Hedwigia, 2012, 141, pp.201-236. ⟨hal-00740202⟩