Morphological and molecular evidence for two new species of Tetragonopterus (Characiformes: Characidae) from central Brazil

The combination of morphological and molecular data of Tetragonopterus species collected in the Rio Araguaia basin allows the recognition of two undescribed species that are presented in this article. These species are distinguished from their congeners (Tetragonopterus anostomus, Tetragonopterus argenteus, Tetragonopterus carvalhoi, Tetragonopterus chalceus and Tetragonopterus rarus) by characters related to the number and morphology of the teeth, the numbers of gill rakers on the upper and lower limbs of the first gill arch, the number of predorsal scales and the overall colour pattern. In addition, the analysis of mitochondrial DNA sequences identified an accentuated genetic distance between these two new species and their congeners. A discussion of the phylogenetic relationships within Tetragonopterus is provided. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

Marcadores citológicos no cariótipo de espécies de Leptodactylus (Amphibia, Anura, Leptodactylidae) analisado com técnicas de citogenética clássica e molecular

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sistemática molecular de Atta laevigata (Smith 1858) e Acromyrmex balzani (Emery 1890)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The history of the introduction of the giant river prawn, Macrobrachium cf. rosenbergii (Decapoda, Palaemonidae), in Brazil: new insights from molecular data

The giant river prawn, Macrobrachium cf. rosenbergii, is one of the most cultivated freshwater prawns in the world and has been introduced into more than 40 countries. In some countries, this prawn is considered an invasive species that requires close monitoring. Recent changes in the taxonomy of this species (separation of M. rosenbergii and M. dacqueti) require a re-evaluation of introduced taxa. In this work, molecular analyses were used to determine which of these two species was introduced into Brazil and to establish the geographic origin of the introduced populations that have invaded Amazonian coastal waters. The species introduced into Brazil was M. dacqueti through two introduction events involving prawns originating from Vietnam and either Bangladesh or Thailand. These origins differ from historical reports of the introductions and underline the need to confirm the origin of other exotic populations around the world. The invading populations in Amazonia require monitoring not only because the biodiversity of this region may be affected by the introduction, but also because admixture of different native haplotypes can increase the genetic variability and the likelihood of persistence of the invading species in new habitats.

Molecular identification, phylogeny and geographic distribution of Brazilian mangrove oysters (Crassostrea)

Oysters (Ostreidae) manifest a high degree of phenotypic plasticity, whereby morphology is of limited value for species identification and taxonomy. By using molecular data, the aim was to genetically characterize the species of Crassostrea occurring along the Brazilian coast, and phylogenetically relate these to other Crassostrea from different parts of the world. Sequencing of the partial cytochrome oxidase c subunit I gene (COI), revealed a total of three species of Crassostrea at 16 locations along the Brazilian coast. C. gasar was found from Curuçá (Pará state) to Santos (São Paulo state), and C. rhizophorae from Fortim (Ceará state) to Florianópolis (Santa Catarina state), although small individuals of the latter species were also found at Ajuruteua beach (municipality of Bragança, Pará state). An unidentified Crassostrea species was found only on Canela Island, Bragança. Crassostrea gasar and C. rhizophorae grouped with C. virginica, thereby forming a monophyletic Atlantic group, whereas Crassostrea sp. from Canela Island was shown to be more similar to Indo-Pacific oysters, and either arrived in the Atlantic Ocean before the convergence of the Isthmus of Panama or was accidentally brought to Brazil by ship.

Taxonomic implications of molecular studies on Northern Brazilian Teredinidae (Mollusca: Bivalvia) specimens

The current taxonomy of the Teredinidae (shipworms) is wholly based on morphology and up to now no molecular studies of the phylogeny of this group have been published. In the present study the relationships between four genera of the subfamilies Teredininae and Bankiinae were established and the efficiency of the 16S rRNA gene in characterizing four Teredinidae species was tested. Phylogenetic trees support the grouping of Bankia fimbriatula with Nausitora fusticula and of Neoteredo reynei with Psiloteredo healdi, but the genetic distances do not justify the classification of these species into two distinct subfamilies. The results show that B. fimbriatula, N. reynei and P. healdi specimens from the coast of the Brazilian state of Pará have five distinct 16S rRNA haplotypes, with one N. reynei haplotype differing from the other haplotypes in respect to at least seven sequences sites, indicating the existence of two very distinct sympatric lineages.

Filogenia molecular e taxonomia do grupo Anolis chrysolepis Duméril & Bibron, 1837 (Squamata, Polychrotidae)

A Amazônia é considerada a maior floresta tropical contínua do mundo e diversos mecanismos têm sido propostos para tentar explicar a sua alta diversidade biológica. Um dos mecanismos mais discutidos desde sua proposição é a hipótese dos Refúgios, que se baseia na retração da floresta em períodos mais secos, isolando a fauna de florestas em refúgios imersos em uma matriz de vegetação aberta. Essas retrações e subseqüentes expansões em períodos mais mésicos provocariam a interrupção do fluxo gênico entre as populações isoladas e poderiam gerar especiação. Contudo, estudos moleculares recentes indicam que a diversificação de espécies de vertebrados de florestas tropicais provavelmente precede o período pleistocênico, originalmente indicado na hipótese dos Refúgios como o período em que esses eventos teriam ocorrido. A espécie politípica Anolis chrysolepis, juntamente com Anolis bombiceps, foi previamente estudada como um típico exemplo de diversificação gerada pelas flutuações climáticas do Pleistoceno, embora estudos posteriores tenham domonstrado a presença de grande divergência molecular entre parte das subespécies, indicando uma separação mais antiga desses táxons e levantando o questionamento sobre seu status taxonômico. Utilizamos o gene mitocondrial ND2 para investigar as relações filogenéticas entre as subespécies de Anolis chrysolepis e os táxons determinados em estudos anteriores como mais próximos a elas. Além disso, a sua morfologia e o seu status taxonômico foram revisados, a fim de verificar a congruência entre os dados morfológicos e moleculares, determinando se os táxons previamente reconhecidos morfologicamente são espécies válidas. Com base nos dois conjuntos de dados, nós elevamos as cinco subespécies do grupo Anolis chrysolepis ao status de espécies, diagnosticamos cada uma delas com comentários sobre as principais diferenças morfológicas entre as espécies irmãs e fornecemos novos dados de distribuição.

Pseudoplatystoma metaense and P. orinocoense (Siluriformes: Pimelodidae) from the Orinoco basin, Venezuela: cytogenetic and molecular analyses

The genus Pseudoplatystoma includes catfish species distributed throughout the fresh waters of South America. These species are important fisheries resources and play a significant ecological role due to their piscivorous and migratory habits. The taxonomy of this genus is still debated: traditionally, only three species have been recognised, but recently, this number was raised to eight. The validity of these eight morphospecies, however, was not confirmed by two subsequent molecular phylogenetic studies, which identified either five or four main clades. In this study, we focused on the two morphospecies restricted to the Orinoco basin, P. metaense and P. orinocoense, which have been assigned to either the same or different clades in previous studies. We carried out cytogenetic analyses to describe their unknown karyotypes and to look for cytotaxonomic markers. We also analysed their mitochondrial sequences in order to assign the sampled specimens to the previously identified molecular clades. The two presumptive species show similar karyotypes (2n=56, 42 biarmed and 14 uniarmed chromosomes) and cytogenetic features in terms of the constitutive heterochromatin distribution and the number and location of minor and major ribosomal genes. Thus, no species-specific chromosome markers could be identified. The analysis of cytochrome b and cytochrome oxidase I mitochondrial genes (carried out by retrieving all the mtDNA Pseudoplatystoma sequences available in GenBank) distributed the sampled specimens into two distinct molecular clades and confirmed the need to re-evaluate, by parallel morphological and molecular analyses, the monophyly of some lineages.

Molecular phylogeny resolves a taxonomic misunderstanding and places Geisleria close to Absconditella s. str. (Ostropales: Stictidaceae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The first molecular phylogeny of Chilodontidae (Teleostei: Ostariophysi: Characiformes) reveals cryptic biodiversity and taxonomic uncertainty

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphological and molecular characterization and phylogenetic relationships of a new species of trypanosome in Tapirus terrestris (lowland tapir), Trypanosoma terrestris sp nov., from Atlantic Rainforest of southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Molecular study on endemic cattleya species from brazilian flora

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Taxonomic review of the species of Mugil (Teleostei: Perciformes: Mugilidae) from the Atlantic South Caribbean and South America, with integration of morphological, cytogenetic and molecular data

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evolution of species diversity in the genus Chamaecostus (Costaceae): molecular phylogenetics and morphometric approaches

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Differentiation and species status of the Neotropical yellow-eared bats Vampyressa pusilla and V. thyone (Phyllostomidae) with a molecular phylogeny and review of the genus

A systematic re-evaluation of Vampyressa pusilla warrants the elevation of V. p. thyone from subspecies to species rank based on its distinction from the allopatric V. p. pusilla. Morphological, mensural, chromosomal, and mitochondrial differences define each of these two taxa as divergent lineages. Vampyressa pusilla is endemic to the Atlantic Forest of southeastern South America and V. thyone is found allopatrically in northwestern South America, Central America, and southern Mexico. A molecular phylogenetic analysis of the mtDNA ND3-4 gene region using restriction endonuclease cut sites resulted in a monophyletic, although weakly supported Vampyressa ingroup with Chiroderma, and a clade of Mesophylla and Ectophylla as successive basal outgroup lineages. The phylogeny within Vampyressa, with the exception of V. melissa which is most similar to V. thyone based on karyotypes and morphology, had a topology of ((pusilla + thyone) + ((brocki + nymphaea) + bidens))).