scholarly journals Diversity, Distribution and Occurrence of Fishes in Begnas Lake, Pokhara, Nepal

ZOO-Journal ◽  
2019 ◽  
Vol 5 ◽  
pp. 16-22
Author(s):  
Kishor K Pokharel ◽  
Sapana Chand
Keyword(s):  
Species Composition ◽  
Size Range ◽  
Market Price ◽  
Fish Diversity ◽  
Future Studies ◽  
Average Size

Present paper deals with the diversity of fishes in Begnas Lake, Pokhara. Fishes were identified and their occurrence, average size range, weight and market price were determined. Altogether 17 species of fishes belonging to five orders, seven families and 17 genera were recorded, of which 11 species were indigenous, while six species were exotic. Family cyprinidae was dominant in terms of both species composition and occurrence. Knowledge of fish diversity has been expected as a useful tool for both quality and quantity harvesting of fish as well as for future studies.

scholarly journals Formula-Driven, Size-Tunable Synthesis of PMMA Nanoparticles by Varying Surfactant Concentration

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1834
Author(s):  
Brian L. Kamras ◽  
Nooshin Mirzanasiri ◽  
Daniel K. Korir ◽  
Sujata Mandal ◽  
Shreya L. Hariharakumar ◽  
...  
Keyword(s):  
Surfactant Concentration ◽  
Size Range ◽  
Sodium Dodecyl ◽  
Synthetic Method ◽  
Decay Function ◽  
Amine Functionalized ◽  
Independent Variable ◽  
Average Size ◽  
20 Nm ◽  
Size Data

In this communication, we present a streamlined, reproducible synthetic method for the production of size-tunable poly(methyl methacrylate) (PMMA) nanoparticles (PMMANPs) and amine-functionalized block-copolymer PMMANPs (H2N-PMMANPs) by varying subcritical concentrations (i.e., below the concentration required to form micelles at 1 atm and 20 °C) of sodium dodecyl sulfate (SDS). We plotted the Z-average size data against SDS concentration, which revealed a second-order exponential decay function, expressed as A 1 e − x t 1 + A 2 e − x t 2 + y 0 . The surfactant concentration (wt./wt.%) has been selected as independent variable x. This function is valid at least for the size range of 20 nm to 97 nm (PMMANPs) and 20 nm to 133 nm (H2N-PMMANPs).

Estuarine characteristics, water quality and heavy metal contamination as determinants of fish species composition in intermittently open estuaries

2017 ◽  
Vol 68 (5) ◽  
pp. 941 ◽  
Author(s):  
K. O'Mara ◽  
A. Miskiewicz ◽  
M. Y. L. Wong
Keyword(s):  
Water Quality ◽  
Species Composition ◽  
Fish Species ◽  
Metal Contamination ◽  
Fish Assemblages ◽  
Anthropogenic Activities ◽  
Estuarine Fish ◽  
Fish Diversity ◽  
Eastern Australia ◽  
Fish Species Composition

Estuaries are critical aquatic environments that are used by many fish during their life cycle. However, estuaries often suffer from poor water quality as a result of anthropogenic activities. Fish diversity studies in estuaries are common, although few have examined whether correlations exist between water quality, metal contamination and fish assemblages. In the present study we investigated the effect of abiotic conditions, heavy metals and estuary characteristics on the abundance, diversity and composition of fish in four intermittently open estuaries along the Illawarra coast of south-eastern Australia. The heterogeneity of environmental conditions was reflected in the fish assemblages in each estuary. Environmental variables predicted fish species composition, and estuaries in particularly poor condition contained few species (estuarine residents) in high abundance, indicating their ability to acclimatise and survive in conditions that are hostile to other species. Overall, these findings demonstrate that estuarine fish assemblages may be useful indicators of estuary condition and reveal the importance of managing anthropogenic activities in the surrounding catchment to improve water quality so that biodiversity of fish can be restored in these estuarine environments.

Synthesis and Characterization of Superparamagnetic NiFe2O4 Nanoparticles

2010 ◽  
Vol 663-665 ◽  
pp. 1325-1328 ◽  
Author(s):  
De Hui Sun ◽  
De Xin Sun ◽  
Yu Hao
Keyword(s):  
Room Temperature ◽  
Size Range ◽  
X Ray Diffraction ◽  
Inverse Spinel ◽  
Cubic Crystal ◽  
Xrd Pattern ◽  
X Ray ◽  
Nife2o4 Nanoparticles ◽  
Average Size

The superparamagnetic NiFe2O4 nanoparticles were synthesized using a hydrothermal technology through P123 sphere micelles as ‘nanoreactor’ in this work. Their morphologies, structures, surface properties and magnetism were characterized by FE-SEM, XRD, FTIR, and VSM, respectively. The nickel ferrite samples are nearly spherical and homogeneous nanoparticles with average size range of about 50-120 nm. They possess superparamagnetism at room temperature and higher saturation magnetization. X-ray diffraction (XRD) pattern confirms that the samples belong to the cubic crystal system with an inverse-spinel structure. Fourier transform infrared (FTIR) absorption spectrum indicates that the NiFe2O4 nanoparticles are stabilized by the P123 adsorbed on the surface of nanoparticles.

scholarly journals Microplastics in Marine and Estuarine Species From the Coast of Portugal

2021 ◽  
Vol 9 ◽  
Author(s):  
João Pequeno ◽  
Joana Antunes ◽  
Viren Dhimmer ◽  
Filipa Bessa ◽  
Paula Sobral
Keyword(s):  
Mytilus Galloprovincialis ◽  
Soft Tissues ◽  
Size Range ◽  
Trachurus Trachurus ◽  
Potential Toxicity ◽  
Future Studies ◽  
Scomber Colias ◽  
Sado Estuary ◽  
Scrobicularia Plana ◽  
The Individual

Microplastics (MP) have been confirmed as emerging pollutants in the marine environment due to their ubiquity, bioavailability, persistence and potential toxicity. This study contributes with valuable data regarding the abundance and characteristics of the MP found in five species collected from Portugal. The mussel Mytilus galloprovincialis (n = 140) was collected from the Tagus estuary and Porto Covo coastal area, the peppery furrow shell Scrobicularia plana (n = 140) and the polychaete Marphysa sanguinea (n = 30) both from the Sado estuary, and Trachurus trachurus (n = 82) and Scomber colias (n = 82) fished off Figueira da Foz and Sesimbra. Soft tissues of all individuals were digested using a KOH (10%) solution, which allowed the extraction of MP. All studied species presented MP. In a total of 502 MP observed from all samples, 80% were fibers and 20% were fragments, with a size range of 73 μm–4,680 μm and blue was the most common color recorded (46%). The frequency of occurrence of MP was higher in T. trachurus (70%) and lowest in M. sanguinea (17%). MP abundance ranged from 0.30 ± 0.63 MP. ind−1 in S. plana, to 2.46 ± 4.12 MP. ind−1 in S. colias. No significant correlation was found between the individual biometric parameters and total MP, fibers and fragments ingested by each species. The FTIR analysis revealed that polyester and polyethylene were the most common polymers present. These results can be used as a reference for future studies regarding the use of indicator species for monitoring MP pollution in the coast of Portugal.

scholarly journals Patterns of Pelagic Fish Diversity in Floodplain Lakes of Whitewater and Blackwater Drainage Systems Within the Central Amazon River Basin of Brazil

2021 ◽  
Vol 9 ◽  
Author(s):  
Flávia K. Siqueira-Souza ◽  
Lawrence E. Hurd ◽  
Kedma C. Yamamoto ◽  
Maria Gercilia M. Soares ◽  
Gregory J. Cooper ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
River Basin ◽  
Amazon Basin ◽  
Pelagic Fish ◽  
Floodplain Lakes ◽  
Fish Diversity ◽  
River Systems ◽  
Amazon River Basin ◽  
Central Amazon

The Amazon River Basin, one of the world’s most threatened ecosystems, has an enormous diversity of fish species, a result of temporally and spatially complex habitat containing biogeochemically different river systems. The annual hydrologic cycle results in floodplain lakes during low water and inundates forests during high water, exposing fish to different resources and environmental conditions. The two principal river systems in the central Brazilian Amazon are blackwater, with nutrient-poor acidic water, and nutrient-rich whitewater. Although species-rich, the Amazon Basin is data-poor in terms of comparative studies on a regional scale. We analyzed data sets from independent sampling studies of pelagic fish in 16 floodplain lakes, nine whitewater (Rio Solimões) and seven blackwater (Rio Negro), in the central Amazon Basin of Brazil. Our findings suggest striking similarities in pelagic fish diversity patterns. Species richness was virtually equal (165 in whitewater and 168 in blackwater). Both species richness, and number of migratory species, per lake increased toward the confluence of the rivers in both systems in our study. The proportion of unique species was also similar in whitewater lakes and blackwater (41 and 43%, respectively), boosting total regional richness to 237 species. However, species composition in whitewater lakes was more homogenous (lower β diversity), and species composition was associated with conductivity and pH in whitewater, but with dissolved oxygen and transparency in blackwater. Therefore, regional fish diversity cannot be represented by sampling one lake or even one drainage system, but must include multiple lakes from both systems. These two systems may differ in sensitivity to anthropogenic stressors such as damming and deforestation.

scholarly journals Reproduction and community structure of fish from winter catch sites from industrial shrimp bycatch from the northeast and southeast Mexican Pacific

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4460
Author(s):  
Jorge de Jesus Tirado-Ibarra ◽  
Mariany Loya-Rodriguez ◽  
Jose Carlos Morales-Arevalo ◽  
Isabel Rosario Muñoz-Garcia ◽  
Francisco Martinez-Perez ◽  
...  
Keyword(s):  
Community Structure ◽  
Fish Species ◽  
Fish Diversity ◽  
Target Species ◽  
Importance Value Index ◽  
Importance Value ◽  
Mexican Pacific ◽  
Shrimp Fishery ◽  
Average Size ◽  
First Maturity

The shrimp fishery is one of the most important fisheries in the world, although the low selectivity from trawling nets has led to the capture of a large number of non-target species. Shrimp-bycatch species include a large number of fish and invertebrate species, of which fish species are the most abundant. The present study aims to determine the community structure as well as the average sizes at first maturity of the fish species from shrimp-bycatch caught from industrial fisheries in the Mexican Pacific from Sinaloa to Guerrero, from January to March 2015. The shrimp-bycatch fish diversity value was found to be 2.22. A total of 37 species of finfish were found, of which five were considered rare. The fish species with the highest Importance Value Index (IVI) levels were Pseudupeneus grandisquamis, Paralichthys woolmani, Lutjanus peru and Diapterus peruvianus. The average size at first maturity was calculated for all species. Of the analysed organisms, 90% were in the juvenile stage, including species with riverine and artisanal fisheries. The present study demonstrates the risk within marine populations to different non-target species due to the poor selectivity of shrimp trawls.

scholarly journals Sampling efficiency of a protocol to measure Odonata diversity in tropical streams

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248216
Author(s):  
Joana Darc Batista ◽  
Victor Rennan Santos Ferreira ◽  
Helena Soares Ramos Cabette ◽  
Lourivaldo Amancio de Castro ◽  
Paulo De Marco ◽  
...  
Keyword(s):  
Species Composition ◽  
Environmental Monitoring ◽  
Sampling Effort ◽  
Sampling Efficiency ◽  
Sampling Protocol ◽  
Future Studies ◽  
Different Types ◽  
Local Species ◽  
Over Time ◽  
Local Species Pool

Odonata can be sampled following different types of protocols. In Brazil, the most used protocol is the scanning in fixed areas method, where a 100-meter transect is delimited in one of the stream margins, subdivided into 20 segments measuring 5 meters. Despite being universally used, the methodological efficiency or limitations of this protocol for Odonata has never been tested. In this scenario, our objective was to assess the efficiency of the sampling protocol to measure the richness and composition of Odonata in three fundamental aspects: the time of sampling and sampling effort over time and space. We show that the best sampling efficiency was achieved in collections performed at noon, in transects measuring 100 meters, requiring at least two samplings in the same location, supporting the procedures traditionally adopted by many studies with the group. While comparing species composition, we did not see any implication between the different treatments on the capture of the local species pool. However, we highlight and discuss some possible methodological flaws when using this protocol to sample specific Odonata groups. We believe the results obtained are fundamental in the inventory of species and to conduct future studies, as well as to aid conservative measures that use the order Odonata as a tool for environmental monitoring.

scholarly journals The effects of aquaculture activities on species composition and diversity of native freshwater fish populations

2018 ◽  
Vol 31 ◽  
pp. 17
Author(s):  
Selin Ertürk Gürkan ◽  
Şükran Yalçin Özdilek
Keyword(s):  
Species Composition ◽  
Rapid Development ◽  
Relative Proportion ◽  
Sustainable Use ◽  
Control Site ◽  
Fish Farm ◽  
Fish Populations ◽  
Fish Diversity ◽  
Significant Difference ◽  
Abundance And Diversity

The rapid development of the aquaculture industry in recent years and the increase in the intensity of production has raised questions regarding potential environmental impacts. Understanding intra- and interspecific relationships between native and cultured species is important for sustainable use of natural resources. This study investigated the spatial and temporal effects of a fish farm constructed next to a river on the relative abundance and diversity of natural fish populations. Sampling was conducted at three stations, upstream and down stream from a trout farm and at a control site, on Kocabas stream in Çanakkale (Turkey) monthly between August 2015 and July 2016. There was no significant difference among the three stations in fish diversity. However, a remarkable seasonal and spatial variation in the composition and relative proportion of the indigenous fish assemblage were observed among the three stations. In conclusion, the fish farm might have influenced species composition and relative abundances particularly at the downstream station.

scholarly journals Facile synthesis of graphene quantum dots from glucan and their application as a deoxidizer and in cell imaging

2020 ◽  
pp. 174751982097393
Author(s):  
Jialu Shen ◽  
Weifeng Chen ◽  
Xiang Liu
Keyword(s):  
Quantum Dots ◽  
Driving Force ◽  
Biomedical Applications ◽  
Cell Imaging ◽  
Size Range ◽  
Graphene Quantum Dots ◽  
Reducing Agents ◽  
Facile Synthesis ◽  
Average Size

A facile and effective route to synthesize graphene quantum dots for cell imaging and as a deoxidizer by using glucan as a precursor is developed. AuNPs are successfully synthesized by mixing of graphene quantum dots and Au(III) salts without any additional reductants. The reducing driving force of these graphene quantum dots is much weaker than that of strong reducing agents such as NaBH4. The sizes of the as-synthesized AuNPs are much larger, with an average size of 15 nm. Notably, this size range is specifically useful and optimal for the application of AuNPs in biomedical applications. In addition, the as-synthesized graphene quantum dots are also successfully applied in cell imaging.

Synthesis and Characterization of CoFe2O4 Nanoparticles

2011 ◽  
Vol 261-263 ◽  
pp. 533-536 ◽  
Author(s):  
Zhen Feng Cui ◽  
Dehui Sun
Keyword(s):  
Solution Method ◽  
Size Range ◽  
Information Storage ◽  
Resonance Imaging ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Rhombohedral Crystal ◽  
Average Size

We synthesized the magnetic CoFe2O4nanoparticles using a solution method in the presence of hexamethylenetetramine (HMTA) at 85 °C for 6 h. Their morphologies, structures, surface properties and magnetism were characterized by Field emission scanning electron microscopy (FE-SEM) images, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and Vibrating sample magnetometer (VSM), respectively. FE-SEM results show that the synthesized samples are irregular nanoparticles with average size range of about 40-120 nm. XRD confirms that the samples belong to the rhombohedral crystal system. The magnetic CoFe2O4nanoparticles have the potential application in magnetic resonance imaging, high-density information storage and drug delivery.

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