A New Variant B Chromosome in Auchenipteridae: The Role of (GATA)n and (TTAGGG)n Sequences in Understanding the Evolution of Supernumeraries in Trachelyopterus

2021 ◽  
pp. 1-12
Author(s):  
Denise Felicetti ◽  
Chrystian A.G. Haerter ◽  
Lucas Baumgärtner ◽  
Leonardo M. Paiz ◽  
Fábio H. Takagui ◽  
...  
Keyword(s):  
River Basin ◽  
B Chromosome ◽  
Sympatric Species ◽  
Neotropical Region ◽  
B Chromosomes ◽  
Amazon River ◽  
Amazon River Basin ◽  
Telomeric Sequences ◽  
Paraguay River ◽  
New Variant

Basic and molecular cytogenetic techniques were carried out in 3 Neotropical region populations of catfishes, two of Trachelyopterus galeatus (one from the marshlands of Paraguay River basin and another from Lago Catalão, Amazon River basin) and one of Trachelyopterus porosus, a sympatric population to T. galeatus from the Amazon River basin. This study aimed to describe and understand the structure and evolution of Trachelyopterus B chromosomes, mainly through physical mapping of repetitive elements. A diploid number of 58 chromosomes was found for all individuals, as well as the presence of B chromosomes. For T. porosus this is the first report of a supernumerary. The sympatric species of T. galeatus and T. porosus from Amazon River had 1–3 B chromosomes and T. galeatus from Paraguay River had 1–2 B chromosomes, all of them showed intra- and interindividual numerical variation. Two females of T. porosus exhibited a new variant B chromosome (B2), previously not seen in Auchenipteridae, which might have originated from B1 chromosomes. All B chromosomes were entirely heterochromatic. In contrast to all complement A and B2 chromosomes, in which the telomeric sequences were found in the telomeric regions, B1 chromosomes of all populations were totally marked by (TTAGGG)n probes. (GATA)n sequence sites were found through all complement A chromosomes, but B1 and B2 chromosomes exhibited only a clustered block in one of the chromosome arms. The most frequent B chromosomes (B1) in all populations/species, including those previously studied in Auchenipteridae catfishes, share the following characteristics: totally heterochromatic, small, metacentric, with accumulation of repetitive (TTAGGG)n sequences, and a low number of (GATA)n copies, which might suggest a common ancient origin in Trachelyopterus species/populations.

scholarly journals Genome assembly and annotation of the tambaqui (Colossoma macropomum): an emblematic fish of the Amazon River Basin

Gigabyte ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Alexandre Wagner Silva Hilsdorf ◽  
Marcela Uliano-Silva ◽  
Luiz Lehmann Coutinho ◽  
Horácio Montenegro ◽  
Vera Maria Fonseca Almeida-Val ◽  
...  
Keyword(s):  
River Basin ◽  
Genome Assembly ◽  
Amazon River ◽  
Amazon River Basin ◽  
Colossoma Macropomum

In-stream turbines for sustainable hydropower development in the Amazon river basin

2021 ◽  
Author(s):  
Suyog Chaudhari ◽  
Erik Brown ◽  
Raul Quispe-Abad ◽  
Emilio Moran ◽  
Norbert Mueller ◽  
...  
Keyword(s):  
River Basin ◽  
Large Scale ◽  
Ecological Impacts ◽  
Amazon River ◽  
River Ecology ◽  
Amazon River Basin ◽  
Hydropower Development ◽  
Continental Scale ◽  
Large Dams ◽  
Hydropower Potential

<p>Given the ongoing and planned hydropower development projects in the Amazon River basin, appalling losses in biodiversity, river ecology and river connectivity are inevitable. These hydropower projects are proposed to be built in exceptionally endemic sites, setting records in environmental losses by impeding fish movement, altering flood pulse, causing large-scale deforestation, and increasing greenhouse gas emissions. With the burgeoning energy demand combined with the aforementioned negative impacts of conventional hydropower technology, there is an imminent need to re-think the design of hydropower to avoid the potentially catastrophic consequences of large dams. It is certain that the Amazon will undergo some major hydrological changes in the near future because of the compounded effects of climate change and proposed dams, if built with the conventional hydropower technology. In this study, we present a transformative hydropower outlook that integrates low-head hydropower technology (e.g., in-stream turbines) and multiple environmental aspects, such as river ecology and protected areas. We employ a high resolution (~2km) continental scale hydrological model called LEAF-Hydro-Flood (LHF) to assess the in-stream hydropower potential in the Amazon River basin. We particularly focus on quantifying the potential and feasibility of employing instream turbines in the Amazon instead of building large dams. We show that a significant portion of the total energy planned to be generated from conventional hydropower in the Brazilian Amazon could be harnessed using in-stream turbines that utilize kinetic energy of water without requiring storage. Further, we also find that implementing in-stream turbines as an alternative to large storage-based dams could prove economically feasible, since most of the environmental and social costs associated with dams are eliminated. Our results open multiple pathways to achieve sustainable hydropower development in the Amazon to meet the ever-increasing energy demands while minimizing hydrological, social, and ecological impacts. It also provides important insight for sustainable hydropower development in other global regions. The results presented are based on a manuscript under revision for Nature Sustainability.</p>

scholarly journals The spatial variability of actual evapotranspiration across the Amazon River Basin based on remote sensing products validated with flux towers

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Victor Hugo da Motta Paca ◽  
Gonzalo E. Espinoza-Dávalos ◽  
Tim M. Hessels ◽  
Daniel Medeiros Moreira ◽  
Georges F. Comair ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Spatial Variability ◽  
River Basin ◽  
Actual Evapotranspiration ◽  
Amazon River ◽  
Amazon River Basin

A new species of Mastiglanis Bockmann 1994 (Siluriformes: Heptapteridae) from the Amazon River basin, Peru

Zootaxa ◽  
2020 ◽  
Vol 4820 (2) ◽  
pp. 323-336
Author(s):  
DARIO R. FAUSTINO-FUSTER ◽  
HERNÁN ORTEGA
Keyword(s):  
New Species ◽  
River Basin ◽  
Morphological Analysis ◽  
Valid Species ◽  
Amazon River ◽  
Freshwater Species ◽  
X Rays ◽  
Amazon River Basin ◽  
A New Species ◽  
Pelvic Fin

Mastiglanis is a genus of heptapterid catfish represented by two valid species. These freshwater species are widely distributed along the Amazon, Orinoco, and Maroni River basins. However, a taxonomic review of specimens collected in the Putumayo and Nanay rivers, Amazon River basin in Peru revealed a new species of Mastiglanis. A morphological analysis was completed for morphometric (36 measurements) and meristic (20 counts) data. Osteological counts and descriptions were made from clear and stained specimens and x-rays images. The new species of Mastiglanis differs from M. asopos and M. durantoni by having a long pelvic fin, short snout, eight branched anal-fin rays, and a higher number of vertebrae and gill rakers. The distribution of the new species is restricted to the upper Amazon River basin.

scholarly journals Revision of Tympanopleura Eigenmann (Siluriformes: Auchenipteridae) with description of two new species

2015 ◽  
Vol 13 (1) ◽  
pp. 1-46 ◽  
Author(s):  
Stephen J. Walsh ◽  
Frank Raynner Vasconcelos Ribeiro ◽  
Lúcia Helena Rapp Py-Daniel
Keyword(s):  
New Species ◽  
River Basin ◽  
The Body ◽  
Junior Synonym ◽  
Amazon River ◽  
Middle Portion ◽  
Amazon River Basin ◽  
Two New Species ◽  
Gas Bladder ◽  
Adult Body

The Neotropical catfish genus Tympanopleura, previously synonymized within Ageneiosus, is revalidated and included species are reviewed. Six species are recognized, two of which are described as new. Tympanopleura is distinguished from Ageneiosus by having an enlarged gas bladder not strongly encapsulated in bone; a prominent pseudotympanum consisting of an area on the side of the body devoid of epaxial musculature where the gas bladder contacts the internal coelomic wall; short, blunt head without greatly elongated jaws; and smaller adult body size. Species of Tympanopleura are distinguished from each other on the basis of unique meristic, morphometric, and pigmentation differences. Ageneiosus melanopogon and Tympanopleura nigricollis are junior synonyms of Tympanopleura atronasus. Tympanopleura alta is a junior synonym of Tympanopleura brevis. A lectotype is designated for T. brevis. Ageneiosus madeirensis is a junior synonym of Tympanopleura rondoni. Tympanopleura atronasus, T. brevis, T. longipinna, and T. rondoni are relatively widespread in the middle and upper Amazon River basin. Tympanopleura cryptica is described from relatively few specimens collected in the upper portion of the Amazon River basin in Peru and the middle portion of that basin in Brazil. Tympanopleura piperata is distributed in the upper and middle Amazon River basin, as well as in the Essequibo River drainage of Guyana.

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