AN UNUSUAL SPINE-BEARING<i>PINNULARIA</i>SPECIES FROM THE ANTARCTIC LIVINGSTON ISLAND (SOUTH SHETLAND ISLANDS)

Abstract

A new spine-bearing Pinnularia species, Pinnularia gemella sp. nov., is described from asediment core taken on the Antarctic Livingston Island (South Shetland Islands, southernAtlantic Ocean). The morphology of this species was examined using scanning electronmicroscopy. The species is easily recognizable by the presence of a continuous row of small,spathulate spines on one side of the valve. Using these interlocking spines, the species formssmall colonies with the frustules lying in juxtaposition. The morphology and colonial formof the new species is compared to all other spine-bearing species such as P. sofia Van deVijver &amp; Le Cohu andlor colonial species such as P. cardinaliculus (A. Schmidt) Cleve. Theecology of the new species is derived from the ecological preferences of the associated flora.