Silvia M P B Guimarães

• PhD
• Research Associate at Instituto de Botânica

The taxonomic position of Halymenia floridana is a long-standing issue that needed to be assessed using DNA sequences of material from the type locality (Florida, USA). Here, we examined the vegetative and reproductive morphoanatomy, and rbcL sequence data of topotypes and additional specimens from Brazil. Our results resolved the topotypes of ‘H....

Proposal of Cryptonemia floridana comb. nov. (Halymeniaceae, Rhodophyta) based on rbcL gene analysis of collections from type locality and female reproductive morphology Abstract: The taxonomic position of Halymenia floridana is a long-standing issue that needed to be assessed using DNA sequences of material from the type locality (Florida, USA). H...

Molecular sequence analyses of specimens previously identified as Cirrulicarpus sp. in the southeastern Brazil (Espírito Santo coast), indicated that they are more closely related to the genus Meredithia than to the genus Cirrulicarpus. The new species Meredithia dichotoma is herein proposed to accommodate this uncommon and endemic taxon, morpholog...

DNA sequence analyses have demonstrated that Gelidium as currently circumscribed is not monophyletic and has three distinctive lineages: Gelidium sensu stricto that includes the generitype Gelidium corneum, the Capreolia group, and another lineage that includes two distinct clades formed by species from the eastern Pacific and western Atlantic Ocea...

The small size (< 5 mm) of marine microfilamentous green algae makes it difficult to identify based on field collections, remaining largely unnoticed. To catalogue the diversity of these diminutive marine algae, a combination of culture-based taxonomic studies and DNA barcoding has proven to be a successful approach. During subtidal surveys in the...

A small red alga was isolated into culture from rhodoliths collected on the Piauí coast, northeastern Brazil. Molecular data from the plastid-encoded rbcL gene, combined with morphological and ultrastructural evidence, demonstrated that it belongs to the genus Rhodachlya and supports the proposal of a new species, R. westii. The new species was cha...

The exploration of seaweed diversity in poorly studied habitats has often led to the discovery of new species. Sand-covered rocks are an example, as they received less attention than sand-free rocky intertidal habitats during seaweed diversity surveys in Brazil. In sand-covered rocks from Espírito Santo and Rio de Janeiro we found an alga whose mor...

Seven species of the economically important agarophyte genus Pterocladiella were previously reported from Brazil: P. australafricanensis, P. bartlettii, P. beachiae, P. caerulescens, P. capillacea, P. sanctarum and P. taylorii. Only P. australafricanensis, P. bartlettii, P. beachiae and P. capillacea were previously confirmed by molecular data. Thi...

Because of phenotypic plasticity, undefined specific boundaries, and specimens that are rarely fertile, species recognition in Gelidiales has been extremely difficult and controversial. Fifteen species of Gelidiellaceae and Gelidiaceae have been reported in Brazil with the majority in regional floristic studies or species lists. Thus, Gelidiales sp...

Abstract An updated synthesis of cyanobacteria and algae information is presented for Brazil aiming to refine the data gathered to date and evaluate the progress of the biodiversity knowledge about these organisms in the country since the publication of the Catálogo de Plantas e Fungos do Brasil. The results of 2015 showed an increase of 1,250 spec...

The Abrolhos Bank, encompassing a wide portion of the Brazilian continental shelf, harbors the world's largest rhodolith bed, which plays an important role in calcium carbonate production in the South Atlantic Ocean. Little is known about the community structure and species composition of this habitat. The aim of this study was to test the hypothes...

Apresenta-se uma síntese atualizada de informações sobre algas no Brasil objetivando refinar os dados reunidos até o presente, bem como avaliar os avanços sobre o conhecimento da diversidade de algas no país desde a publicação do Catálogo de Plantas e Fungos do Brasil. Os resultados de 2015 mostraram um acréscimo de 1.250 espécies (35.7%) a um tota...

Morphological identification of species in the order Gelidiales can be difficult and controversial because of phenotypic plasticity, the low numbers of reproductive specimens and poorly defined taxonomic boundaries. A DNA barcoding survey of Brazilian speci- mens of Gelidiales, employing neighbor-joining and Automatic Barcode Gap Discovery analyses...

Endophytic and epiphytic infections have caused serious problems for Kappaphycus farmers, such as reduction in biomass production and decrease in the yield and quality of carrageenan. During environmental monitoring from January 2011 to December 2012, along Pitimbu Beach, Paraíba State, northeastern Brazil, drifting thalli of Kappaphycus alvarezii...

We report here the first occurrence of Bangiopsis subsimplex (Mont.) F.Schmitz (Rhodophyta) for the northeastern coast of Brazil. The specimen was isolated from a laboratory sample of mollusk shells collected in Baía de Todos os Santos (Bimbarras Island, Brazil) and was held in sterilized seawater (33 UPS) enriched with 25% Provasoli solution. In t...

Calcium carbonate production by marine organisms is an essential process in the global budget of $CO_3^{2 - }$ , and coralline reefs are the most important benthic carbonate producers. Crustose coralline algae (CCA) are well recognized as the most important carbonate builders in the tropical Brazilian continental shelf, forming structural reefs and...

The Antarctic Continent is undergoing environmental alterations due to global climate changes and anthropic activities. The knowledge of the biodiversity and of the ecophysiology of the organisms in this region is of essential importance to delineate strategies of protection and for the management of such a fragile region of the planet. Among the o...

The Trindade and Martin Vaz island group (TMVIG) is located at about 1,120 km off the Brazilian coast. Despite its importance, highlighted by the presence of several endemic fish species, the TMVIG lacks detailed information on the structure of fish and benthic assemblages. Presented here is the first quantitative assessment of reef fish and benthi...

This study describes the predominantly tropical, subtidal seaweed populations growing on rhodoliths between 4 and 18 m depth in the southern part of Espirito Santo State (Brazil). Qualitative and quantitative sampling revealed species–rich algal communities, comprising 167 species. Three species of rhodophytes represent new records for the Brazilia...

This study describes the predominantly tropical, subtidal seaweed populations growing on rhodoliths between 4 and 18 m depth in the southern part of Espírito Santo State (Brazil). Qualitative and quantitative sampling revealed species-rich algal communities, comprising 167 species. Three species of rhodophytes represent new records for the Brazilia...

Scinaia halliae (Scinaiaceae, Rhodophyta) is analysed morphologically and taxonomically from the coast of Espírito Santo and Bahia, Brazil. Specimens were collected on the intertidal and in infralitoral zones from 16 m depth through a dredge Holme. Descriptions and illustrations are presented, as well as comments on habitat and geographical distrib...

Scinaia halliae (Scinaiaceae, Rhodophyta) is analysed morphologically and taxonomically from the coast of Espírito Santo and Bahia, Brazil. Specimens were collected on the intertidal and in infralitoral zones from 16 m depth through a dredge Holme. Descriptions and illustrations are presented, as well as comments on habitat and geographical distrib...

Espírito Santo State lies in the transition region (18°-21° S) between the tropical and subtropical marine-algal provinces and is considered the richest area of the Brazilian flora. The subtidal substratum presents extensive areas of rhodoliths associated with a diversified marine biota. A detailed exploration using Scuba diving technique has revea...

The vegetative and reproductive morphology of the crustose red alga Peyssonnelia japonica (Segawa) Yoneshigue was re-examined based on the holotype specimen and recent collections from various localities in Japan, including the type locality, and Hawaii. This species is characterized by the following features: thallus with appressed margins, perith...

Seven taxa of benthic marine rodophytes are reported for the first time from the Brazil littoral: Acrochaetium corymbiferum (Thur. in Le Jolis) Batters, A. liagorae Børgesen, Aglaothamnion herveyi (M.Howe) Aponte, D.L. Ballant. & J.N. Norris, Crouanophycus latiaxis (L.A. Abbott) Athanas., Grallatoria reptans M.Howe and Gelidiella sanctarum Feldmann...

Taxonomic studies of an extensive collection of flattened members of the Solieriaceae considered by many authors to be species of Agardhiella, Eucheuma, Meristotheca, and Meristiella lead us to conclude that they represent only two genera in Brazil: Agardhiella, including A. ramosissima (Harvey) Kylin and A. floridana (Kylin) Gabrielson ex Guimarãe...

Rhodoliths are one of the most extensive benthic communities of the Brazilian continental shelf, but their structure is poorly known. The richest marine flora of Brazil's coastal zone is found in Espirito Santo State and its diversity has been partly associated with the presence of extensive areas of rhodoliths, extending from the intertidal zone t...

A detailed study of the vegetative and reproductive morphology of Chondrophycus flagelliferus from Brazil is provided. The species possesses axial segments, each bearing two periaxial cells, a situation characteristic for the genus Chondrophycus. Within Chondrophycus, C. flagelliferus belongs to the subgenus Palisadi, section Palisadi, on the basis...

Chemical and spectroscopic methods showed that the major KCl-precipitated galactans from Meristiella gelidium (Solieriaceae) are iota/kappa/nu-hybrid carrageenans with the former one in higher proportion. These carrageenans showed, by HPSEC-MALLS analysis, unimodal symmetrical peaks with MW of 425.6–956.7 kDa. The effectiveness of the crude extract...

The coast of Espirito Santo State is located in a biogeographic transition zone presenting high diversity. A renewed interest in this region occurred in the 1990s, resulting in various new records and new species descriptions added to the Brazilian marine flora. The study of the infralitoral of this region is just beginning, and a detailed explorat...

The genus Polysiphonia Grev. has a wide circunscription and is heterogeneous in vegetative and reproductive features. This paper presents a detailed study of the genus Polysiphonia sensu lato occurring at São Paulo and Espirito Santo States, Brazil, and an assessment of its morphological characteristics taking into consideration the recent taxonomi...

Hypoglossum hypoglossoides (Stackhouse) Collins & Hervey is reported for the first time from the infralittoral of São Paulo and Santa Catarina states. The species was already reported to the states of Rio de Janeiro, Espírito Santo and Bahia as Hypoglossum tenuifolium (Harvey) J. Agardh var. carolinianum Williams. A detailed description of the morp...

Duas espécies de Cheilosporum foram encontradas no levantamento das espécies do gênero Cheilosporum no litoral do Brasil: C. cultratum (Harvey) Areschoug e C. sagittatum (Lamouroux) Areschoug. A primeira havia sido referida para o Brasil em 1870 por Martens e foi redescoberta para o Atlântico americano. Esta espécie tem distribuição restrita a área...

During a survey of red marine algae from Espirito Santo State, Brazil, five species of Peyssonnelia were collected in the intertidal zone or as drift material: Peyssonnelia armorica (P. Crouan et H.Crouan) Weber-van Bosse in Borgesen, P. borgesenii Weber-van Bosse in Borgesen (the first South Atlantic record), P. boudouresquei Yoneshigue, P. capens...

O presente trabalho cita a ocorrência de Trichogloea requienii no litoral da Bahia, nordeste do Brasil. O gênero é caracterizado por apresentar calcificação moderada na região entre os filamentos assimiladores (córtex) e medula, células mães dos espermatângios dispostas em verticilos sobre as células subterminais corticais, carpogônio localizado no...

The morphology of the parasitic red alga Janczewskia moriformis Setchell is described based on material from Espirito Santo, southeastern Brazil. The parasite was growing on two species of Laurencia, L. flagellifera J. Agardh and L. translucida M.T Fujii et Cordeiro-Marino. Janczewskia moriformis has a wart-like thallus made up of coalescent branch...

Two species of Halymenia C. Agardh (H. vinacea M. Howe et W. R. Taylor and H. brasiliana sp. nov.) from Brazil are described. It is concluded that distinguishing features for species of Halymenia include: habit and dimensions of the plant; thickness of the frond; presence or absence of a differentiated stipe; presence or absence of a rib at the bas...

Petroglossum undulatum Schneider (Rhodophyta, Phyllophoraceae) is recorded for the first time outside the deep water of North and South Carolina. The apparently disjunct distribution of this species may be attributed to insufficient collections in the intermediate geographic areas and to the similarity of the external morphology of this species to...

The vegetative and reproductive development of the parasitic red alga Dawsoniocolax bostrychiae (Joly et Yamaguishi-Tomita) Joly et Yamaguishi-Tomita, a parasite on Bostrychia, was studied. The thallus is a colourless multiaxial pustule which forms secondary pit connections with cells of its host. Reproductive structures develop from outer cortical...

Callus-like structures (CLS) were observed to develop from sectioned tissues of the thallus segments of Grateloupia filiformis Ktzing maintained in Von Stosch enriched-seawater culture medium. Three types were observed: dark CLS originated from pigmented cortical cells, clear CLS and loose clear CLS both originated from colorless medullary cells. D...

Jolyna laminarioides gen. et sp. nov. (Scytosiphonales, Phaeophyceae) is described from Buzios, ‘municipio’ of Cabo Frio, Brazil. The plants consist of one to several erect blades arising from a discoid holdfast. Anatomical features include a meristoderm, an outer and inner cortex, a transition region, a medulla that is composed of elongated cells...

Este trabalho se refere ao desenvolvimento das estruturas de reprodução de Champia minuscula. São apresentados dados detalhados sobre organização do talo, formação e posição do procarpo e desenvolvimento do carposporofito.As estruturas masculinas, nesta espécie, são descritas pela primeira vez.A formação dos espermatângios e tetrasporângios também...