Microplastic pollution in the Amazon Basin: Current scenario, advances and perspectives.

The presence of microplastics (MPs) has been reported in ecosystems in the most different regions of the world and rivers have been identified as one of the main means of transporting this debris to oceans. Recent research shows microplastic deposition and accumulation in the Amazon Basin and, despite being scarce, microplastic pollution is ubiquitous in the region. Of the 9 countries that make up the Amazon Basin, only Brazil, Guyana, Ecuador and Peru have published on the topic, with the main focus on biota (58 %).

Comparative cytogenetics of Serrasalmidae (Teleostei: Characiformes): The relationship between chromosomal evolution and molecular phylogenies.

Serrasalmidae has high morphological and chromosomal diversity. Based on molecular hypotheses, the family is currently divided into two subfamilies, Colossomatinae and Serrasalminae, with Serrasalminae composed of two tribes: Myleini (comprising most of pacus species) and Serrasalmini (represented by Metynnis, Catoprion, and remaining piranha's genera). This study aimed to analyze species of the tribes Myleini (Myloplus asterias, M.

Chromosomal Mapping of Rex Retrotransposons in Tambaqui (Colossoma macropomum Cuvier, 1818) Exposed to Three Climate Change Scenarios.

Greenhouse gas emissions are known to influence the planet's temperature, mainly due to human activities. To allow hypothesis testing, as well as to seek viable alternatives for mitigation, the Intergovernmental Panel on Climate Change (IPCC) suggested 3 main scenarios for changes projected for the year 2100. In this paper, we subjected Colossoma macropomum Cuvier, 1818 (tambaqui) individuals in a microcosm to IPCC scenarios B1 (mild), A1B (intermediate), and A2 (extreme) to test possible impacts on their genome.

Chromosomal Mapping of Repetitive Sequences (Rex3, Rex6, and rDNA Genes) in Hybrids Between Colossoma macropomum (Cuvier, 1818) and Piaractus mesopotamicus (Holmberg, 1887).

Some species of Characiformes are known for their high economic value, such as Colossoma macropomum and Piaractus mesopotamicus, and are used in aquaculture programs to generate hybrid tambacu (interbreeding of C. macropomum females and P. mesopotamicus males).

Chromosomal Mapping of Transposable Elements of the Rex Family in the Bristlenose Catfish, Ancistrus (Siluriformes, Loricariidae), from the Amazonian Region.

Repetitive DNA sequences are present in the genome of basically every known organism, and transposable elements (TE) are one of the most representative sequences involved in chromosomal rearrangements and the genomic evolution of eukaryotes. In fish, the non-LTR retrotransposon TEs, Rex1, Rex3, and Rex6, are widely distributed in fish genomes and are the best-characterized TEs in several species. In the current study, three of these retroelements were physically mapped, through fluorescent in situ hybridization (FISH), in 7 species (71 specimens) of the genus Ancistrus, known as bristlenose catfish: Ancistrus ranunculus, Ancistrus sp.

Is the Karyotype of Neotropical Boid Snakes Really Conserved? Cytotaxonomy, Chromosomal Rearrangements and Karyotype Organization in the Boidae Family.

Boids are primitive snakes from a basal lineage that is widely distributed in Neotropical region. Many of these species are both morphologically and biogeographically divergent, and the relationship among some species remains uncertain even with evolutionary and phylogenetic studies being proposed for the group. For a better understanding of the evolutionary relationship between these snakes, we cytogenetically analysed 7 species and 3 subspecies of Neotropical snakes from the Boidae family using different chromosomal markers.

First Cytogenetic Description of Microsternarchus bilineatus (Gymnotiformes: Hypopomidae) from Negro River (Brazilian Amazon).

Microsternarchus bilineatus is a neotropical electric fish species widely distributed in Amazonian ecosystems. This work reports the first karyotypic description of the species M. bilineatus, which presented 2n = 48 chromosomes, with a distinct karyotypic formula between the sexes: males with 21 metacentric (m)/submetacentric (sm) + 27 subtelocentric (st)/acrocentric (a) and fundamental number (FN) = 69 and females with 20 m/sm + 28 st/a and FN = 68.

Chromosome mapping of repetitive sequences in four Serrasalmidae species (Characiformes).

The Serrasalmidae family is composed of a number of commercially interesting species, mainly in the Amazon region where most of these fishes occur. In the present study, we investigated the genomic organization of the 18S and 5S rDNA and telomeric sequences in mitotic chromosomes of four species from the basal clade of the Serrasalmidae family: Colossoma macropomum, Mylossoma aureum, M. duriventre, and Piaractus mesopotamicus, in order to understand the chromosomal evolution in the family.