Remarks on the morphology and distribution of some rare centric diatoms in southern Brazilian continental shelf and slope waters

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 -34ºS), under the influence of Tropical, Subtropical, Subanta...

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Main Authors: Marinês Garcia, Clarisse Odebrecht
Format: Article
Language:English
Published: Universidade de São Paulo 2012-12-01
Series:Brazilian Journal of Oceanography
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592012000400002
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author Marinês Garcia
Clarisse Odebrecht
author_facet Marinês Garcia
Clarisse Odebrecht
author_sort Marinês Garcia
collection DOAJ
description 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 -34ºS), 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 <35). Lower frequencies were observed for Asterolampra marylandica, Asteromphalus elegans, Asteromphalus heptactis and Spatangidium arachne. Four species of Azpeitia were observed: A. barronii and A. neocrenulata for the first time in the South Atlantic Ocean while A. africana and A. nodulifer had already been registered in equatorial and southern areas of Brazil. All Azpeitia species were rare (19%) in offshore samples (100-200 m depth. Remarks on the morphology based on light and scanning electron microcopy observations are provided along with their distribution in the study area.<br>O trabalho apresenta informações morfológicas e sobre a ocorrência de diatomáceas atuais da família Asterolampraceae e de espécies de Azpeitia encontradas na plataforma continental e talude do extremo sul do Brasil no Oceano Atlântico Sul (28 -34ºS), sob influência de Águas Tropical, Subtropical e Subantártica, bem como do aporte terrestre do Rio La Plata e da Lagoa dos Patos. O plâncton foi amostrado (rede de 20 µm; arrastos verticais) em 27 estações de coleta no inverno de 2005 e verão de 2007. Entre as Asterolampraceae, Asteromphalus flabellatus foi a espécie mais freqüente (57% das amostras), principalmente nas amostras de inverno (92%) em água Subtropical de Plataforma, mas também sob influência da pluma do Rio La Plata (salinidade <35). Asterolampra marylandica, Asteromphalus elegans, Asteromphalus heptactis and Spatangidium arachne ocorreram em menor frequência. Quatro espécies de Azpeitia foram observadas: A. barronii e A. neocrenulata, são citadas pela primeira vez para o Oceano Atlântico Sul, enquanto A. africana e A. nodulifer, já foram reportadas em áreas equatoriais e meridionais brasileiras. Todas as espécies de Azpeitia foram raras (19%) nas amostras de alto-mar (entre as isobatas de 100-200 m). Considerações sobre a morfologia baseada em observações ao microscópio óptico e eletrônico de varredura são fornecidas juntamente com dados de distribuição das espécies na área estudada.
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spelling doaj.art-7a60ac75809d406b8d2e23dc9e3eb14c2022-12-22T01:20:54ZengUniversidade de São PauloBrazilian Journal of Oceanography1679-87591982-436X2012-12-01604415427Remarks on the morphology and distribution of some rare centric diatoms in southern Brazilian continental shelf and slope watersMarinês GarciaClarisse OdebrechtThis 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 -34ºS), 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 <35). Lower frequencies were observed for Asterolampra marylandica, Asteromphalus elegans, Asteromphalus heptactis and Spatangidium arachne. Four species of Azpeitia were observed: A. barronii and A. neocrenulata for the first time in the South Atlantic Ocean while A. africana and A. nodulifer had already been registered in equatorial and southern areas of Brazil. All Azpeitia species were rare (19%) in offshore samples (100-200 m depth. Remarks on the morphology based on light and scanning electron microcopy observations are provided along with their distribution in the study area.<br>O trabalho apresenta informações morfológicas e sobre a ocorrência de diatomáceas atuais da família Asterolampraceae e de espécies de Azpeitia encontradas na plataforma continental e talude do extremo sul do Brasil no Oceano Atlântico Sul (28 -34ºS), sob influência de Águas Tropical, Subtropical e Subantártica, bem como do aporte terrestre do Rio La Plata e da Lagoa dos Patos. O plâncton foi amostrado (rede de 20 µm; arrastos verticais) em 27 estações de coleta no inverno de 2005 e verão de 2007. Entre as Asterolampraceae, Asteromphalus flabellatus foi a espécie mais freqüente (57% das amostras), principalmente nas amostras de inverno (92%) em água Subtropical de Plataforma, mas também sob influência da pluma do Rio La Plata (salinidade <35). Asterolampra marylandica, Asteromphalus elegans, Asteromphalus heptactis and Spatangidium arachne ocorreram em menor frequência. Quatro espécies de Azpeitia foram observadas: A. barronii e A. neocrenulata, são citadas pela primeira vez para o Oceano Atlântico Sul, enquanto A. africana e A. nodulifer, já foram reportadas em áreas equatoriais e meridionais brasileiras. Todas as espécies de Azpeitia foram raras (19%) nas amostras de alto-mar (entre as isobatas de 100-200 m). Considerações sobre a morfologia baseada em observações ao microscópio óptico e eletrônico de varredura são fornecidas juntamente com dados de distribuição das espécies na área estudada.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592012000400002BrasilBiogeografiaNovos registrosAsterolampraceaeAzpeitiaBrazilBiogeographyNew recordsAsterolampraceaeAzpeitia
spellingShingle Marinês Garcia
Clarisse Odebrecht
Remarks on the morphology and distribution of some rare centric diatoms in southern Brazilian continental shelf and slope waters
Brazilian Journal of Oceanography
Brasil
Biogeografia
Novos registros
Asterolampraceae
Azpeitia
Brazil
Biogeography
New records
Asterolampraceae
Azpeitia
title Remarks on the morphology and distribution of some rare centric diatoms in southern Brazilian continental shelf and slope waters
title_full Remarks on the morphology and distribution of some rare centric diatoms in southern Brazilian continental shelf and slope waters
title_fullStr Remarks on the morphology and distribution of some rare centric diatoms in southern Brazilian continental shelf and slope waters
title_full_unstemmed Remarks on the morphology and distribution of some rare centric diatoms in southern Brazilian continental shelf and slope waters
title_short Remarks on the morphology and distribution of some rare centric diatoms in southern Brazilian continental shelf and slope waters
title_sort remarks on the morphology and distribution of some rare centric diatoms in southern brazilian continental shelf and slope waters
topic Brasil
Biogeografia
Novos registros
Asterolampraceae
Azpeitia
Brazil
Biogeography
New records
Asterolampraceae
Azpeitia
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592012000400002
work_keys_str_mv AT marinesgarcia remarksonthemorphologyanddistributionofsomerarecentricdiatomsinsouthernbraziliancontinentalshelfandslopewaters
AT clarisseodebrecht remarksonthemorphologyanddistributionofsomerarecentricdiatomsinsouthernbraziliancontinentalshelfandslopewaters