Karyotypic variation in the long-whiskered catfish Pimelodus blochii Valenciennes, 1840 (Siluriformes, Pimelodidae) from the lower Tapajós, Amazonas and Trombetas Rivers

The genus Pimelodus LaCépède, 1803 comprises 35 formally recognized species distributed along the major neotropical river basins. Despite conservatism in diploid number with 2n=56, an intense variation of chromosomal morphology (karyotypic formula) has been documented in Pimelodus species. In the present study, we analyzed karyotypes of 20 specimens, identified as Pimelodus blochii Valenciennes, 1840 and collected from the lower courses of the Tapajós, Amazonas and Trombetas Rivers. The karyotypes were characterized by Giemsa conventional staining, C-banding, silver staining (Ag-NOR) and fluorescent in situ hybridization (FISH) with 5S and 18S rDNA probes. The karyotypes showed 2n=56 chromosomes in fish from the Tapajós River. In contrast, fish from the Amazonas and Trombetas Rivers had 2n=58. The nucleolus organizing regions were labeled on the short arm of an acrocentric chromosome as demonstrated by silver staining and FISH. Signals for 18S and 5S rDNA were co-localized on one chromosome pair. Our results demonstrate karyotypic divergence between Tapajós and Amazonas-Trombetas populations of P. blochii, interpreted as supporting the existence of a species complex in this taxon

A new species of Hoplias malabaricus species complex (Characiformes: Erythrinidae) from the Crepori River, Amazon basin, Brazil

A new species belonging to the Hoplias malabaricus complex from the Amazon basin, Brazil, is described. The new species is characterized by 15–16 predorsal scales, 37–39 lateral-line scales, 5 scales from dorsal fin to lateral line, 38–39 vertebrae, iii-iv, 7–8 anal-fin rays, ii-iv, 12–15 caudal-fin rays, last vertical series of scales on the base of caudal-fin rays forming a straight line, 6–7 dark bands in anal fin and no distinctive dark bands or blotches on flanks. The new species is also distinguished from other congeners of the H. malabaricus species-group by means of landmark-based morphometrics and DNA Barcoding (Cytochrome c Oxidase I gene). An identification key to species of the H. malabaricus species complex is provided.Fil: Auzier Guimarães, Karen Larissa. Universidade Federal do Pará; BrasilFil: Rosso, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: González Castro, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Souza, Fujiie Belém. Universidade Federal do Pará; BrasilFil: Díaz de Astarloa, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Ribeiro Rodrigues, Luís Reginaldo. Universidade Federal do Pará; Brasi

Estudos Artísticos

Os quinze artigos que aqui se reúnem, nesta edição da Revista Croma, são também as propostas para uma nova política, esclarecida, crítica, e mais exigente. Podem observar-se padrões de intervenção, que partem de algumas dimensões comuns: a interpelação do observador, a criação de novos públicos, a proposta de contribuir para uma mudança alargada, partindo de questões a que não são alheias as problemáticas contemporâneas. As questões de género, a emancipação pós-colonial, a sustentabilidade, as migrações, a massificação, a globalização, o fim das ideologias e a ascensão do populismo, entre outras, constituem os contextos da atualidadeinfo:eu-repo/semantics/publishedVersio

Estudo da comercialização de peixes ornamentais da família Loricariidae (Siluriformes) em Santarém/PA.

No Brasil, o comércio de peixes ornamentais de ambientes dulcícolas ainda depende essencialmente da atividade extrativista, principalmente na região amazônica. O estado do Pará se apresenta como um dos principais fornecedores de peixes ornamentais da família Loricariidae, sobretudo nas bacias do rio Xingu e Tapajós. No presente estudo analisamos a comercialização de peixes ornamentais da família Loricariidae oriundos do rio Tapajós e comercializados por empresas instaladas na cidade de Santarém. Os dados primários foram obtidos a partir das Guias de Transporte Animal (GTA) e Guias de Transito de Peixes com fins Ornamentais e de Aquariofilia (GTPON), perfazendo o período de janeiro/2013 a dezembro/2016. Foram comercializados um total de 136.705 exemplares que geraram a receita bruta de R$ 365.013,80. As espécies Baryancistrus sp. (LDA33), Hypancistrus sp. (L260), Pseudacanthicus sp. (L273) e Peckoltia compta (L134) são as mais produtivas e economicamente rentáveis, sendo responsáveis por 59.6% da receita bruta gerada no período de janeiro/2013 a dezembro/2016. A produção de peixes ornamentais em Santarém/PA é oriunda da atividade extrativista da pesca artesanal e quase totalmente comercializada no mercado nacional. Os resultados obtidos são importantes para a compreensão da cadeia produtiva de peixes ornamentais da bacia do Tapajós, pois ainda existem pouco conhecimento publicado sobre a estrutura da pesca ornamental nesta região

Karyotypic and Molecular Analysis of <i>Pterygoplichthys pardalis</i> (Castelnau 1855) from the Lower Amazon River

Pterygoplichthys pardalis is an armored catfish native to South America and an important resource for the ornamental fish industry. Recently, several exotic populations have been introduced into rivers on five continents. Despite its commercial and environmental importance, P. pardalis is poorly studied from a genetic perspective. In this study, we analyzed the karyotype of P. pardalis from the Amazon River and molecular variations in the mitochondrial gene Cytochrome oxidase I (COI) between native and exotic populations. The karyotype presented diploid number 2n = 52 and NF = 100 without cytogenetic variation between males and females. Nucleolus organizer regions (Ag-NOR) in the distal region of the long arm of pair 12 coincided with the 18S hybridization signal, whereas 5S was syntenic to this chromosome but localized in the short arm. The constitutive heterochromatin was restricted in the distal regions of pairs 4, 12, 25, and 26. Telomeric probes showed only distal hybridization signals. The karyotype of P. pardalis diverged from that of its congeners, and COI molecular variation revealed four haplotypes. The Philippine population revealed the greatest diversity with three haplotypes, while haplotype H1 was the most abundant and observed in both native and exotic populations. This new genetic data contributes to species management and provides useful information from an aquaculture perspective

DNA barcoding of fish fauna from low order streams of Tapajós River basin.

The Amazon basin harbors a megadiverse fish fauna spread in an intricate network of big rivers and small streams. The Amazonian streams are home of many small sized fishes that remains poorly documented. In order to accelerate the scientific knowledge on these important aquatic systems we adopted a modern integrative approach joining morphology and molecular tools to investigate the ichthyofauna assemblages from low order streams situated on the lower Tapajós River Basin. Cytochrome c Oxidase I (COI) DNA barcodes from 252 specimens collected from 10 stream sites were obtained. The combined analysis revealed 29 species, 21 genera and 11 families. Cryptic diversity was evidenced in Knodus sp.1, Aequidens epae and Copella callolepis, in which deep genetic divergence were detected (intraspecific distances: 20.48%, 7.99% and 3.77%, respectively). The putative new species showed closer relationships with their counterparts occurring in the Tapajós-Xingu water drainages

Cytogenetic and DNA barcoding reveals high divergence within the trahira, Hoplias malabaricus (Characiformes: Erythrinidae) from the lower Amazon River

Molecular and cytogenetic data have provided evidence of cryptic speciation in the widespread South American trahira, Hoplias malabaricus. In the present study, karyotypes and DNA barcode sequences of specimens from seven populations inhabiting the lower Amazon River were analyzed in order to characterize the levels of genetic divergence within a single karyomorph. All the specimens presented karyotypes with 2n = 40 chromosomes (20m+20sm) that were consistent with the species' C karyomorph. The DNA barcodes revealed six haplogroups, with clear divergence between populations from Brazil and Argentina. The results support the species complex hypothesis and indicate that a single karyomorph of H. malabaricus may harbor more than one specie

Chromosomal Diversification in Pseudacanthicus Species (Loricariidae, Hypostominae) Revealed by Comparative Mapping of Repetitive Sequences

Pseudacanthicus is a genus of Neotropical fish with eight valid species, in addition to numerous lineages not formally identified. It occurs along the Amazon and Tocantins River basins, in Suriname and in the Guiana shield. There are no karyotypic data in the literature for species of this genus. Here, the karyotypes of three Pseudacanthicus species (P. spinosus, P. leopardus and Pseudacanthicus sp.) were comparatively analyzed by classical cytogenetics and fluorescence in situ hybridization using 18S and 5S rDNA probes, U2 snDNA and telomeric sequences. The analyzed species presented 52 chromosomes and KF = 18 m + 34 sm. Constitutive heterochromatin occurred in blocks on a few chromosomes. The 18S rDNA occurred in a single pair; interestingly, P. leopardus presented only one locus of this sequence in its diploid genome. The 5S rDNA sequence occurred in only one pair in P. leopardus, and in multiple sites in Pseudacanthicus sp. and P. spinosus. The snDNA U2 occurred in only one pair in all analyzed species. Telomeric sequences did not show interstitial sites. Although Pseudacanthicus species share the same 2n and KF, repetitive sequence analysis revealed karyotypic diversity among these species. The occurrence of DNA double-strand breaks related to fragile sites, unequal crossing over and transpositions is proposed as the mechanism of karyotypic diversification, suggesting that the conservation of the karyotypic macrostructure is only apparent in this group of fish

Four new species of Pristimantis Jiménez de la Espada, 1870 (Anura: Craugastoridae) in the eastern Amazon.

The Pristimantis genus (Anura: Craugastoridae) is the most diverse among all vertebrates with 531 described species. The highest diversity occurs in Ecuador (215 species), followed by Colombia (202), Peru (139), Venezuela (60), Brazil (30), Bolivia (17), Guyana (6) Suriname and French Guiana (5). The genus is divided into 11 species groups. Of these, the P. conspicillatus group (containing 34 species), distributed in extreme southeastern Costa Rica, Isla Taboga (Panama), northern South America (from Colombia to eastern Guyana), south Bolivia, and is the best represented in Brazil (16 species). The main characteristics of this group are the tympanic membrane and tympanic annulus distinct (except in P. johannesdei); dorsum smooth or shagreen; dorsal lateral fold present or absent; usually smooth belly, but may be weakly granular in some species; toe V slightly larger than the toe III. Most of the taxonomic inconsistencies in species of Pristimantis could be due to its much conserved morphology and the lack of comprehensive taxonomic evaluations. Thus, an ongoing challenge for taxonomists dealing with the Pristimantis genus is the ubiquitous abundance of cryptic species. In this context, accurate species delimitation should integrate evidences of morphological, molecular, bioacoustics and ecological data, among others. Based on an integrative taxonomy perspective, we utilize morphological, molecular (mtDNA) and bioacoustic evidence to describe four new species of the Pristimantis conspicillatus group from the eastern Amazon basin. Pristimantis giorgii sp. nov. is known from the Xingu/Tocantins interfluve and can be distinguished from the other Pristimantis species of the region by presenting discoidal fold, dorsolateral fold absent, vocalization composed of three to four notes and genetic distance of 7.7% (16S) and 14.8% (COI) from P. latro, the sister and sympatric species with respect P. giorgii sp. nov.. Pristimantis pictus sp. nov. is known to the northern Mato Grosso state, Brazil, and can be distinguished from the other species of Pristimantis by presenting the posterior surface of the thigh with light yellow patches on a brown background, also extending to the inguinal region, vocalization consisting of four to five notes and a genetic distance of 11.6% (16S) and 19.7% (COI) from P. pluvian sp. nov., which occurs in sympatry. Pristimantis pluvian sp. nov. is known to the northern Mato Grosso state, Brazil, and may be distinguished from the other Pristimantis species by having a posterior surface of the thigh reddish and vocalization composed of two notes. Pristimantis moa sp. nov. is known to the northern Tocantins state and southwestern Maranhão state. This species can be distinguished from the other Pristimantis species by possessing slightly perceptible canthal stripe, external thigh surface with dark yellow spots on brown background, vocalization consisting of three to five notes and genetic distance of 2.3-11.7 (16S) and 10.5-23.1 (COI) for the new Pristimantis species of this study

Correction: Four new species of Pristimantis Jiménez de la Espada, 1870 (Anura: Craugastoridae) in the eastern Amazon.

[This corrects the article DOI: 10.1371/journal.pone.0229971.]