scholarly journals eDNA in a bottleneck: Obstacles to fish metabarcoding studies in megadiverse freshwater systems

2021 ◽  
Author(s):  
Jake M. Jackman ◽  
Chiara Benvenuto ◽  
Ilaria Coscia ◽  
Cintia Oliveira Carvalho ◽  
Jonathan S. Ready ◽  
...  
Keyword(s):  
Freshwater Systems

Fish stranding in freshwater systems: Sources, consequences, and mitigation

2012 ◽  
Vol 103 ◽  
pp. 133-141 ◽  
Author(s):  
Alexander Nagrodski ◽  
Graham D. Raby ◽  
Caleb T. Hasler ◽  
Mark K. Taylor ◽  
Steven J. Cooke
Keyword(s):  
Freshwater Systems

scholarly journals Utilization of low molecular weight organic compounds by the filterable fraction of a lotic microbiome

2020 ◽  
Author(s):  
Lydia-Ann J Ghuneim ◽  
Marco A Distaso ◽  
Tatyana N Chernikova ◽  
Rafael Bargiela ◽  
Evgenii A Lunev ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Community Dynamics ◽  
Lag Phase ◽  
Minor Role ◽  
Low Molecular Weight ◽  
Freshwater Systems ◽  
North Wales ◽  
Clusters Of Orthologous Groups ◽  
A Minor ◽  
Substrate Addition

Abstract Filterable microorganisms participate in dissolved organic carbon (DOC) cycling in freshwater systems, however their exact functional role remains unknown. We determined taxonomic identity and community dynamics of prokaryotic microbiomes in the 0.22 µm-filtered fraction and unfiltered freshwater from the Conwy River (North Wales, UK) in microcosms and, using targeted metabolomics and 14C-labelling, examined their role in utilization of amino acids, organic acids, and sugars spiked at environmentally-relevant (nanomolar) concentrations. To identify changes in community structure, we used 16S rRNA amplicon and shotgun sequencing. Unlike the unfiltered water samples where the consumption of DOC was rapid, the filtered fraction showed a 3-days lag phase before the consumption started. Analysis of functional categories of clusters of orthologous groups of proteins (COGs) showed COGs associated with energy production increased in numbers in both fractions with substrate addition. The filtered fraction utilized low-molecular-weight (LMW) DOC at much slower rates than the whole community. Addition of nanomolar concentrations of LMW DOC did not measurably influence the composition of the microbial community nor the rate of consumption across all substrate types in either fraction. We conclude that due to their low activity, filterable microorganisms play a minor role in LMW DOC processing within short residence time of lotic freshwater systems.

scholarly journals Preliminary Screening for Microplastic Concentrations in the Surface Water of the Ob and Tom Rivers in Siberia, Russia

2020 ◽  
Vol 13 (1) ◽  
pp. 80
Author(s):  
Yulia A. Frank ◽  
Egor D. Vorobiev ◽  
Danil S. Vorobiev ◽  
Andrey A. Trifonov ◽  
Dmitry V. Antsiferov ◽  
...  
Keyword(s):  
Surface Water ◽  
Arctic Ocean ◽  
River System ◽  
The Arctic ◽  
Preliminary Screening ◽  
Freshwater Systems ◽  
Ob River ◽  
The Arctic Ocean ◽  
Abundance And Diversity ◽  
Blank Spot

To date, the largest Russian rivers discharging to the Arctic Ocean remain a “blank spot” on the world map of data on the distribution of microplastics in freshwater systems. This study characterizes the abundance and morphology of microplastics in surface water of the Ob River and its large tributary, the Tom River, in western Siberia. The average number of particles for the two rivers ranged from 44.2 to 51.2 items per m3 or from 79.4 to 87.5 μg per m3 in the Tom River and in the Ob River, respectively. Of the recovered microplastics, 93.5% were less than 1 mm in their largest dimension, the largest group (45.5% of total counts) consisted of particles with sizes range 0.30–1.00 mm. Generally, microfragments of irregular shape were the most abundant among the Ob and Tom samples (47.4%) and exceeded microfibers (22.1%), microfilms (20.8%), and microspheres (9.74%) by average counts. Results from this study provide a baseline for understanding the scale of the transport of microplastics by the Ob River system into the Arctic Ocean and add to currently available data on microplastics abundance and diversity in freshwater systems of differing global geographic locations.

Geese as vectors of nitrogen and phosphorous to freshwater systems

Inland Waters ◽  
2016 ◽  
Vol 6 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Lisa Dessborn ◽  
Rebecca Hessel ◽  
Johan Elmberg
Keyword(s):  
Freshwater Systems

scholarly journals Karyotype description of three species of Loricariidae (Siluriformes) and occurrence of the ZZ/ZW sexual system in Hemiancistrus spilomma Cardoso & Lucinda, 2003

2006 ◽  
Vol 4 (1) ◽  
pp. 93-97 ◽  
Author(s):  
Renildo Ribeiro de Oliveira ◽  
Issakar Lima Souza ◽  
Paulo Cesar Venere
Keyword(s):  
Chromosome Pair ◽  
Sex Chromosome ◽  
Sexual System ◽  
Freshwater Systems ◽  
Phylogenetic Studies ◽  
Cytogenetic Data ◽  
Sex Chromosome System

The neotropical freshwater systems have a high number of catfish species (Siluriformes), and many of those are denominated "cascudos" in Brazil. Cytogenetic data about three "cascudos" species fished in the rio Araguaia are described in the present study. The Pterygoplichthys joselimaianus showed 2n=52, with 28 metacentrics (M) chromosomes, 16 submetacentrics (SM) and 8 subtelocentrics/acrocentrics (ST/A) in both sexes. Hemiancistrus spinosissimus showed 2n=52, with karyotype formulae 26M+22SM+4ST, in both sexes. Hemiancistrusspilomma also showed 2n=52, but in this species a ZZ/ZW sex chromosome system (25M+21SM+6ST in females and 24M+22SM+6ST in males) was observed. The cells from H. spinosissimus and P. joselimaianus showed one chromosome pair bearing Ag-NORs, while in the H. spilomma three chromosome pairs bearing Ag-NORs were detected. The data showed in this work reveal particular chromosomal characteristics, important for a good recognition of both Hemincistrus species, and also show the importance of the insertion of cytogenetic data on taxonomic phylogenetic studies.

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