MORPHOLOGICAL DIVERSITY WITHIN THE ACHNANTHIDIUM MINUTISSIMUM SPECIES COMPLEX
Autor(a) principal: | |
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Data de Publicação: | 2012 |
Outros Autores: | , , , |
Tipo de documento: | Artigo de conferência |
Idioma: | por |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10174/8029 |
Resumo: | During a survey of benthic diatoms sampled in watercourses from Mainland Portugal, several Achnanthidium populations morphologically ascribable to the A. minutissimum complex have been found. They clearly belong to the genus Achnanthidium on the basis of the valve outline, radiate striae, uniseriate, wider spaced striae in the centre of the valve and cells shallow‐V‐shaped in girdle view. The raphe valve has a straight central raphe hardly expanding at the centre and a row of elongated areolae in the mantle. Within the genus Achnanthidium these morphotypes belong to the complex of A. minutissimum (Kützing) Czarnecki, due to their straight terminal raphe fissures, in opposition to the species with terminal raphe fissures clearly deflected on the same side of the valve. Since these individuals were abundant in numerous sites, especially in the Centre and North of Portugal, a more detailed examination was performed by means of light (LM) and scanning electron microscopy (SEM). Furthermore, the examination of the environmental characteristics of the sites where they have been sampled allowed us to gather sufficient information on the ecological preferences of the different taxa. The main features that allow the separation of these taxa among each other and from all the other known Achnanthidium species are the different valve outline and dimensions, the size and shape of the central area, the apices shape and the density of the striae throughout the valve and near the apices. The LM and SEM analyses of the type materials of Achnanthidium microcephalum Kützing, Achnanthes minutissima Kützing and A. minutissima var. cryptocephala Grunow in Van Heurck have been done in order to help to clarify the taxonomy of this group. A comparison with the literature on Achnanthidium minutissimum species complex was performed, but the new Portuguese Achnanthidium taxa present a set of distinct morphological and ecological features that separate them well from all other similar species. Furthermore, two of these taxa have already been recorded from French watercourses with similar environmental characteristics. |
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MORPHOLOGICAL DIVERSITY WITHIN THE ACHNANTHIDIUM MINUTISSIMUM SPECIES COMPLEXdiversityAchnanthidium speciesDuring a survey of benthic diatoms sampled in watercourses from Mainland Portugal, several Achnanthidium populations morphologically ascribable to the A. minutissimum complex have been found. They clearly belong to the genus Achnanthidium on the basis of the valve outline, radiate striae, uniseriate, wider spaced striae in the centre of the valve and cells shallow‐V‐shaped in girdle view. The raphe valve has a straight central raphe hardly expanding at the centre and a row of elongated areolae in the mantle. Within the genus Achnanthidium these morphotypes belong to the complex of A. minutissimum (Kützing) Czarnecki, due to their straight terminal raphe fissures, in opposition to the species with terminal raphe fissures clearly deflected on the same side of the valve. Since these individuals were abundant in numerous sites, especially in the Centre and North of Portugal, a more detailed examination was performed by means of light (LM) and scanning electron microscopy (SEM). Furthermore, the examination of the environmental characteristics of the sites where they have been sampled allowed us to gather sufficient information on the ecological preferences of the different taxa. The main features that allow the separation of these taxa among each other and from all the other known Achnanthidium species are the different valve outline and dimensions, the size and shape of the central area, the apices shape and the density of the striae throughout the valve and near the apices. The LM and SEM analyses of the type materials of Achnanthidium microcephalum Kützing, Achnanthes minutissima Kützing and A. minutissima var. cryptocephala Grunow in Van Heurck have been done in order to help to clarify the taxonomy of this group. A comparison with the literature on Achnanthidium minutissimum species complex was performed, but the new Portuguese Achnanthidium taxa present a set of distinct morphological and ecological features that separate them well from all other similar species. Furthermore, two of these taxa have already been recorded from French watercourses with similar environmental characteristics.22nd International Diatom Symposium2013-01-30T12:14:27Z2013-01-302012-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/conferenceObjecthttp://hdl.handle.net/10174/8029http://hdl.handle.net/10174/8029porNOVAIS M.H., ECTOR L., VAN DE VIJVER B., MORAIS M.M. & HOFFMANN L., 2012 - Morphological diversity within the Achnanthidium minutissimum species complex. 22nd International Diatom Symposium, Ghent, Belgium, 26-31 August 201222nd International Diatom Symposium, Ghent, Belgium, 26-31 August 2012naonaosimCentro de Geofísica de Évora - CGEnovaismh@gmail.comector@lippmann.luvandevijver@br.fgov.bemmorais@uevora.pthoffmann@lippmann.lu221Novais, Maria HelenaEctor, LucVijver, Bart Van deMorais, ManuelaHoffmann, Lucieninfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-01-03T18:48:44Zoai:dspace.uevora.pt:10174/8029Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T01:02:25.881938Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
MORPHOLOGICAL DIVERSITY WITHIN THE ACHNANTHIDIUM MINUTISSIMUM SPECIES COMPLEX |
title |
MORPHOLOGICAL DIVERSITY WITHIN THE ACHNANTHIDIUM MINUTISSIMUM SPECIES COMPLEX |
spellingShingle |
MORPHOLOGICAL DIVERSITY WITHIN THE ACHNANTHIDIUM MINUTISSIMUM SPECIES COMPLEX Novais, Maria Helena diversity Achnanthidium species |
title_short |
MORPHOLOGICAL DIVERSITY WITHIN THE ACHNANTHIDIUM MINUTISSIMUM SPECIES COMPLEX |
title_full |
MORPHOLOGICAL DIVERSITY WITHIN THE ACHNANTHIDIUM MINUTISSIMUM SPECIES COMPLEX |
title_fullStr |
MORPHOLOGICAL DIVERSITY WITHIN THE ACHNANTHIDIUM MINUTISSIMUM SPECIES COMPLEX |
title_full_unstemmed |
MORPHOLOGICAL DIVERSITY WITHIN THE ACHNANTHIDIUM MINUTISSIMUM SPECIES COMPLEX |
title_sort |
MORPHOLOGICAL DIVERSITY WITHIN THE ACHNANTHIDIUM MINUTISSIMUM SPECIES COMPLEX |
author |
Novais, Maria Helena |
author_facet |
Novais, Maria Helena Ector, Luc Vijver, Bart Van de Morais, Manuela Hoffmann, Lucien |
author_role |
author |
author2 |
Ector, Luc Vijver, Bart Van de Morais, Manuela Hoffmann, Lucien |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Novais, Maria Helena Ector, Luc Vijver, Bart Van de Morais, Manuela Hoffmann, Lucien |
dc.subject.por.fl_str_mv |
diversity Achnanthidium species |
topic |
diversity Achnanthidium species |
description |
During a survey of benthic diatoms sampled in watercourses from Mainland Portugal, several Achnanthidium populations morphologically ascribable to the A. minutissimum complex have been found. They clearly belong to the genus Achnanthidium on the basis of the valve outline, radiate striae, uniseriate, wider spaced striae in the centre of the valve and cells shallow‐V‐shaped in girdle view. The raphe valve has a straight central raphe hardly expanding at the centre and a row of elongated areolae in the mantle. Within the genus Achnanthidium these morphotypes belong to the complex of A. minutissimum (Kützing) Czarnecki, due to their straight terminal raphe fissures, in opposition to the species with terminal raphe fissures clearly deflected on the same side of the valve. Since these individuals were abundant in numerous sites, especially in the Centre and North of Portugal, a more detailed examination was performed by means of light (LM) and scanning electron microscopy (SEM). Furthermore, the examination of the environmental characteristics of the sites where they have been sampled allowed us to gather sufficient information on the ecological preferences of the different taxa. The main features that allow the separation of these taxa among each other and from all the other known Achnanthidium species are the different valve outline and dimensions, the size and shape of the central area, the apices shape and the density of the striae throughout the valve and near the apices. The LM and SEM analyses of the type materials of Achnanthidium microcephalum Kützing, Achnanthes minutissima Kützing and A. minutissima var. cryptocephala Grunow in Van Heurck have been done in order to help to clarify the taxonomy of this group. A comparison with the literature on Achnanthidium minutissimum species complex was performed, but the new Portuguese Achnanthidium taxa present a set of distinct morphological and ecological features that separate them well from all other similar species. Furthermore, two of these taxa have already been recorded from French watercourses with similar environmental characteristics. |
publishDate |
2012 |
dc.date.none.fl_str_mv |
2012-01-01T00:00:00Z 2013-01-30T12:14:27Z 2013-01-30 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/conferenceObject |
format |
conferenceObject |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10174/8029 http://hdl.handle.net/10174/8029 |
url |
http://hdl.handle.net/10174/8029 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.relation.none.fl_str_mv |
NOVAIS M.H., ECTOR L., VAN DE VIJVER B., MORAIS M.M. & HOFFMANN L., 2012 - Morphological diversity within the Achnanthidium minutissimum species complex. 22nd International Diatom Symposium, Ghent, Belgium, 26-31 August 2012 22nd International Diatom Symposium, Ghent, Belgium, 26-31 August 2012 nao nao sim Centro de Geofísica de Évora - CGE novaismh@gmail.com ector@lippmann.lu vandevijver@br.fgov.be mmorais@uevora.pt hoffmann@lippmann.lu 221 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
22nd International Diatom Symposium |
publisher.none.fl_str_mv |
22nd International Diatom Symposium |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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