ABSTRACT.Hypostomus is a group of fish with numerical and structural karyotypic variability. Among them, only six species, three of which belong to the Amazon basin, show a sex chromosome. In this study, we present the karyotype structure of Hypostomus cf. plecostomus from the Teles Pires river basin in the municipality of Alta Floresta, MT. The species has 2n = 68 and the karyotype formula 14m+ 24sm+ 14st+ 16a [fundamental number (FN) = 120] in males and 15m+ L.C. Oliveira et al. 6626©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (2): 6625-6634 (2015) 24sm+14st+15a (FN = 121) in females and sex chromosomes ZZ/ZW. Argyrophilic nucleolar organizer regions (AgNORs) were identified in two pairs of chromosomes at different positions: short arm of the pair 21and long arm of the pair 27, matching the signals displayed by 18S FISH and indicating multiple NORs. Analysis of band C detected few blocks of constitutive heterochromatin in the pericentromeric regions of most chromosomes and the telomeric regions of some pairs, including the nucleolar pair 21. However, large blocks on the long arm of the nucleolar pair 27 still stood out. GC-rich heterochromatin (CMA 3 ) was visualized only coincidently with nucleolar sites. Mapping of 5S rDNA sites with FISH revealed markings in eight chromosomes, demonstrating synteny between the 18S and 5S sites. The data obtained for H. cf. plecostomus are important for taxonomic studies of this Amazon complex "H. plecostomus group". The occurrence of sex chromosomes in Amazon species of Hypostomus suggests an evolutionary event that is independent of other species in the group.
ABSTRACT. The Iguaçu River basin is a tributary to the upper Paraná River in southern Brazil, and is considered an important aquatic ecoregion that, although having few species of fish, 51-71% of these are apparently endemic. Ancistrus abilhoai is one of three recently described species for this basin and is currently considered endemic to the basin. In this study, we present the chromosomal structure of two populations of Ancistrus abilhoai one collected in the Iguaçu River, in Paraná State, and another collected in the Timbó River, a tributary of the Iguaçu River, in the State of Santa Catarina. Karyotype analyzes were performed in 11 specimens from the Iguaçu River (four females and seven males) and 12 specimens (all males) from Timbó River, revealing 2n = 48 chromosomes with a karyotype formula of 22m + 14sm + 6st + 6a in both populations. Analysis of active nucleolar organizer regions (Ag-NORs) and fluorescent in situ hybridization (FISH) with 18S rDNA probes revealed the submetacentric pair 13 bearing marks at terminal positions on the short arms. Considered as plesiomorphic chromosomal markers in Loricariidae, asynteny 18S and 5S rDNA, and small amounts of heterochromatin were observed. In this study, the first chromosomal data of A. abilhoai are presented with comments on karyotypic characteristics of the genus.
Resumo:A Amazônia é a região com a mais alta biodiversidade do mundo, mas ainda há muitas lacunas sobre o conhecimento de suas espécies e relações ecológicas. Entretanto, a Amazônia também corresponde à região mundial com a maior média de desmatamento, despontando significativamente na derrubada de espécies arbóreas. Nosso objetivo foi investigar a composição da vegetação arbórea da Amazônia conforme categorias de ameaça de extinção e endemismo. Utilizamos a lista de árvores do domínio da Amazônia do banco de dados NeoTropTree e avaliamos essas espécies arbóreas em relação às ameaças e ao status de endemismo nas listas de espécies da International Union for Conservation of Nature and Natural Resources (IUCN) e do Centro Nacional de Conservação da Flora (CNCFlora). Obtivemos 5.482 espécies arbóreas distribuídas em 815 gêneros e 128 famílias. Registramos a presença de 158 espécies ameaçadas segundo a IUCN: 13 (criticamente ameaçadas -CR), 38 (em perigo -EN) e 109 (vulneráveis -VU); e 65 segundo o CNCFlora: 9 (CR), 24 (EN) e 32 (VU), além de 25 espécies endêmicas do Brasil. A família Sapotaceae e a fitofisionomia floresta pluvial abrigam o maior número de espécies com ameaça de extinção. Identificamos várias espécies ameaçadas que estão entre as principais madeiras de lei brasileiras. A ocorrência de espécies em categorias de risco de extinção e endemismo, associada ao acelerado avanço do desmatamento no domínio da Amazônia, evidencia a necessidade de ações urgentes de conservação, com especial atenção para a fitofisionomia floresta pluvial.Palavras-chave: risco de extinção; endemismo; fitofisionomia. Composition, richness and threat categories of Amazonian treesAbstract: Amazon is the region that has the highest biodiversity in the world, but there is still little knowledge about its species and ecological relations. However, Amazon also corresponds to the world region with the highest average of deforestation, resulting in significant tree felling. Our objective was to investigate the composition of Amazon's arboreal vegetation according to categories of extinction threat and endemism. We used the list of trees in the Amazonian domain by the NeoTropTree database and evaluated these species, obtaining information on threats and endemism status from the International Union for Conservation of Nature and Natural Resources (IUCN) and Centro Nacional de Conservação da Flora (CNCFlora) species lists. We obtained 5,482 tree species distributed in 815 genera and 128 families. We recorded the presence of 158 threatened species according to IUCN: 13 critically endangered (CR); 38 endangered (EN); and 109 vulnerable (VU). Based on CNCFlora list, 65 were threatened: 9 CR, 24 EN, and 32 VU, in addition to 25 species described as endemic in Brazil. Sapotaceae family and the rainforest phytophysiognomy harbor the largest number of species threatened with extinction. Besides, we have identified several EN species that are among the main Brazilian hardwoods. The occurrence of species under extinction risk and endemism categories, ...
RESUMO O conhecimento da anatomia do sistema digestório dos peixes fornece subsídios para várias áreas de pesquisa e desenvolvimento para manutenção e conservação dos estoques pesqueiros. O objetivo deste trabalho foi caracterizar a anatomia do tubo digestório de L. fasciatus contribuindo com informações de sua biologia básica. Foram utilizados 05 exemplares, oriundos do rio Teles Pires-Alta Floresta-MT. Os animais foram anestesiados e sacrificados em solução de benzocaína, fixados em solução de formaldeído a 10%, dissecados e fotografados. O esôfago apresentou-se como órgão tubular curto, com mucosa constituída por pregas longitudinais rasas. Estômago sacular em formato de "U", dividido em regiões cárdica, fúndica e pilórica, com mucosa interna formada por pregas primárias e secundárias, papilas e fímbrias. O intestino apresentou forma de "N", composto por três regiões tubulares distintas, intestino anterior, médio e posterior, mucosa formada por pregas circulares e profundas. Os cecos pilóricos se apresentaram como apêndices tubulares digitiformes. O tudo digestório de L. fasciatus se mostrou similar ao de outras espécies deste gênero.
RESUMOO Colossoma macropomum (Tambaqui) é um teleósteo de água doce da Família Characidae, endêmico da bacia Amazônica, de grande interesse econômico. O objetivo deste trabalho foi descrever morfologicamente o estômago do Tambaqui. Foram utilizados seis (6) exemplares jovens com idade entre seis meses e um ano, oriundos da Chácara Esteio, Alta Floresta, MT. O órgão foi fotodocumentado in situ e descrito macroscopicamente, em seguida procedeu-se à retirada de fragmentos deste, que foram processados pelas técnicas histológicas rotineiras para inclusão em parafina e coloração de Hematoxilina e Eosina (HE). O estômago localiza-se na parte mediana da região ventral da cavidade celomática, parcialmente coberto pelas alças intestinais e cecos pilóricos. È do tipo monogástrico, com uma região cárdica, um corpo e uma região pilórica, com curvatura menor e curvatura maior. Microscopicamente, apresenta um epitélio prismático simples acompanhado de mucosa muscular, criptas ou fossetas gástricas dispostas regularmente, vilosidades estomacais e glândulas. A localização e a forma do estômago desta espécie são similares a outras espécies do gênero, assim como suas estruturas histológicas. PALAVRAS-CHAVE: Characidae, Histologia, Peixe, Sistema Digestório. ASPECTS MORPHOLOGICAL OF STOMACH Colossoma macropomum CUVIER, 1818 (TAMBAQUI)ABSTRACT The Colossoma macropomum (Tambaqui) is a freshwater teleost from Characidae family, endemic to the Amazon basin, of great economic interest. The objective of this study was to describe morphologically the stomach of the Tambaqui. They were used six (6) juveniles samples aged between six months and one year, coming from Chácara Esteio, Alta Floresta, MT. The organ was photodocumented in situ and described macroscopically, then proceeded to the removal of fragments thereof, which were processed by routine histological techniques for paraffin embedding and hematoxylin and eosin staining (HE). The stomach is located in the middle part of the ventral region of the coelomic cavity, partially covered by the intestinal loops and pyloric caeca. It was the monogastric type with a cardial region, a body and a pyloric region, with lesser curvature and greater curvature. Microscopically, presented a
In the present study, we analyzed individuals of Hypostomus soniae (Loricariidae) collected from the Teles Pires River, southern Amazon basin, Brazil. Hypostomus soniae has a diploid chromosome number of 2n = 64 and a karyotype composed of 12 metacentric (m), 22 submetacentric (sm), 14 subtelocentric (st), and 16 acrocentric (a) chromosomes, with a structural difference between the chromosomes of the two sexes: the presence of a block of heterochromatin in sm pair No. 26, which appears to represent a putative initial stage of the differentiation of an XX/XY sex chromosome system. This chromosome, which had a heterochromatin block, and was designated proto-Y (pY), varied in the length of the long arm (q) in comparison with its homolog, resulting from the addition of constitutive heterochromatin. It is further distinguished by the presence of major ribosomal cistrons in a subterminal position of the long arm (q). The Nucleolus Organizer Region (NOR) had different phenotypes among the H. soniae individuals in terms of the number of Ag-NORs and 18S rDNA sites. The origin, distribution and maintenance of the chromosomal polymorphism found in H. soniae reinforced the hypothesis of the existence of a proto-Y chromosome, demonstrating the rise of an XX/XY sex chromosome system.
Las hormigas habitan y explotan los hábitats más variados desde el subsuelo hasta el dosel del bosque. Sin embargo, los estudios sobre la diversidad de hormigas de la vegetación son menos frecuentes en el Amazonas. En este artículo enumeramos las especies de hormigas recogidas en el sotobosque de un remanente de bosque en un paisaje del sur de la Amazonia. La lista incluye 32 especies, de las cuales tres (9 %) son nuevos registros para el estado de Mato Grosso, Brasil, siendo una de estas especies muestreadas por primera vez en Brasil.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.