BRAZILIAN JOURNAL OF OCEANOGRAPHY, 60(4):415-427, 2012
REMARKS ON THE MORPHOLOGY AND DISTRIBUTION OF SOME RARE CENTRIC DIATOMS IN SOUTHERN BRAZILIAN CONTINENTAL SHELF AND SLOPE WATERS Marinês Garcia1,* and Clarisse Odebrecht2 1 Universidade Federal de Pelotas - Departamento de Botânica - UFPel (Rua Gomes Carneiro, 1 Prédio da Reitoria 96010-900 Pelotas, RS, Brasil) 2
Universidade Federal do Rio Grande - Instituto de Oceanografia – FURG (Avenida Itália, km 8, 96201-900 Caixa Postal 474 Rio Grande, RS, Brasil) *Corresponding author:
[email protected]
A BSTRACT This paper provides information on the morphology and occurrence of extant diatoms of the family Asterolampraceae and Azpeitia species of the southernmost Brazilian continental shelf and slope waters in the Southwestern Atlantic Ocean (28 - 34°S), under the influence of Tropical, Subtropical, Subantarctic Waters, terrestrial discharges from La Plata River and Lagoa dos Patos lagoon. Plankton was sampled (20 µm net; vertical hauls) at the same 27 stations in winter 2005 and summer 2007. Among Asterolampraceae, Asteromphalus flabellatus was the most frequent species (57% of samples) observed mainly in winter samples (92%) in Subtropical Shelf Water but also under the influence of La Plata River plume (salinity