scholarly journals Characterization of agar from Gracilaria tikvahiae cultivated for nutrient bioextraction in open water farms

2019 ◽  
Vol 89 ◽  
pp. 260-271 ◽  
Author(s):  
Cristina M.R. Rocha ◽  
Ana M.M. Sousa ◽  
Jang K. Kim ◽  
Júlia M.C.S. Magalhães ◽  
Charles Yarish ◽  
...  
Keyword(s):  
Open Water ◽  
Gracilaria Tikvahiae

CHARACTERIZATION OF DEVELOPMENTAL OPEN WATER SWIMMERS

1999 ◽  
Vol 31 (Supplement) ◽  
pp. S284
Author(s):  
J. L. VanHeest ◽  
L. Herr
Keyword(s):  
Open Water

Seasonal residency, activity space, and use of deep-water channels by Greenland sharks (Somnious microcephalus) in an Arctic fjord system

2021 ◽  
Author(s):  
Jena Elizabeth Edwards ◽  
Kevin J. Hedges ◽  
Nigel E. Hussey
Keyword(s):  
Deep Water ◽  
Acoustic Telemetry ◽  
Water Channel ◽  
Open Water ◽  
Activity Space ◽  
Arctic Ecosystems ◽  
Marine Management ◽  
Arctic Fjord ◽  
Somniosus Microcephalus

As Arctic ecosystems become increasingly vulnerable to climate- and human-induced stressors, effective marine management will rely on the characterization of fish movements. Over a six-year study period, the movements of 65 Greenland sharks (Somniosus microcephalus) (41 males, 24 females [mean LT = 2.48 ± 0.50 m]) were monitored using static acoustic telemetry. Shark presence in a typical deep-water fjord was restricted to the summer open-water period. Residency duration varied based on age-class (juvenile [n=17] vs. subadult [n=48]), however, activity space size and extent were comparable. A quarter of tagged sharks (n=16) returned to the system in subsequent years after tagging, with individuals re-detected for a maximum of 4 y. Movements between coastal and offshore waters occurred primarily via a deep-water channel with sharks detected along the channel banks. These multi-year data depict how a potentially vulnerable Arctic predator utilizes a deep-water fjord in the context of the regional development of community inshore and offshore commercial fisheries.

Patterns of Invertebrate Size and Abundance in Aquatic Habitats

1981 ◽  
Vol 38 (8) ◽  
pp. 896-904 ◽  
Author(s):  
Gary G. Mittelbach
Keyword(s):  
Body Size ◽  
Lognormal Distribution ◽  
Prey Size ◽  
Lepomis Macrochirus ◽  
Stomach Contents ◽  
Open Water ◽  
Total Biomass ◽  
Bare Sediment ◽  
Littoral Invertebrates

The size distributions of invertebrate prey found in the vegetation, bare sediment, and open water habitats of a small, Michigan lake were quantified for the months of May through August, 1979. The distribution of prey body size in each habitat generally conformed to a lognormal distribution, allowing a simple characterization of prey size and abundance in each habitat. Seasonally, the abundance of large littoral invertebrates declined markedly, shifting the distribution of prey size in the vegetation and bare sediment habitats towards smaller prey. The total biomass of vegetation-dwelling prey (exclusive of gastropods) also declined dramatically from May to August. These seasonal changes in prey size and abundance were correlated with a reduction in foraging intake for the dominant fish species in the lake, the bluegill sunfish (Lepomis macrochirus). Bluegills whose diet was > 80% vegetation prey showed a > 3-fold decline in stomach contents (prey weight/fish weight) from May to Ausut, during which time prey biomass in the vegetation declined 2.5-fold.Key words: body size, lognormal distribution, benthos, foraging, Lepomis, Michigan

Genetics of Gracilaria tikvahiae (Rhodophyceae). VIII. Phenotypic and genetic characterization of some selected morphological mutants

1982 ◽  
Vol 60 (12) ◽  
pp. 2556-2564 ◽  
Author(s):  
Mohsin U. Patwary ◽  
John P. van der Meer
Keyword(s):  
Wild Type ◽  
Initial Attempt ◽  
Gracilaria Tikvahiae ◽  
Induced Mutants ◽  
Morphological Mutants ◽  
Phenotypic And Genetic Characterization ◽  
Growth Habits ◽  
Selection Of ◽  
Better Than

Morphological mutants of the marine red alga Gracilaria tikvahiae have been isolated in an initial attempt to develop improved strains for mariculture by selection of plants with altered growth habits. Both spontaneous and ethylmethanesulphonate-induced mutants were collected for this study. The phenotypes of the mutants range from plants with extremely fine, highly branched fronds to plants with thick puffy fronds. Among 10 mutants selected for more detailed study, 9 have distinctly different phenotypes. Genetic results identify nine mutant cistrons corresponding to the nine phenotypes. All the phenotypes are transmitted as single, mostly recessive, Mendelian mutations, with possible linkage appearing in two combinations of mutants. Growth trials in culture indicate that at least some of the mutants grow better than a genetically related wild type. In general, plants with increased branching showed the greatest promise.

scholarly journals Characterization of sediment layer composition in a shallow lake: from open water zones to reed belt areas

2014 ◽  
Vol 11 (11) ◽  
pp. 12627-12657
Author(s):  
I. Kogelbauer ◽  
W. Loiskandl
Keyword(s):  
Shallow Lake ◽  
Open Water ◽  
Penetration Resistance ◽  
Measuring System ◽  
High Water Content ◽  
Sediment Layer ◽  
Soil Physics ◽  
Layer Composition

Abstract. Lake sediment characterization, a pre-requirement for the vulnerability assessment of lake ecosystems, demands reliable in situ methods for the characterization of the sediment layer composition. A unified characterization of lake sediments within different lake ecotopes (open water, open water patches within the reed, and the reed) is still a challenge. Each ecotope is covered by different classical scientific disciplines (hydrography and terrestrial remote sensing to soil physics) with their specific characterization methods. However, a complementary tool that bridges the gap between land- and hydrographic surveying methods is still missing. Therefore a combination of soil physical sensors (a capacitive sensor and a cone penetrometer) in a measuring system (CSPS) was introduced. CSPS is a non-acoustic device for the rapid in situ delineation of water-mud-consolidated lakebed interfaces. The system was successfully applied across the different ecotopes at the Neusiedler See, a well-mixed shallow lake rich in fine-grained sediments. The geo-referenced vertical CSPS profiles show ecotope-specific layer composition. The effect of wind induced turbidity, particle size, and electrical conductivity were analysed. The water–mud interface was precisely delineated at the open water due to a persistent high water content gradient, equivalent to a lutocline. The penetration resistance for open water showed either a shallow and highly-compacted consolidated lakebed or a consolidated lakebed with a partially compacted layer above; while in the reed the penetration resistance smoothly increased until reaching the deepest penetration depths.

scholarly journals Characterization of sediment layer composition in a shallow lake: from open water zones to reed belt areas

2015 ◽  
Vol 19 (3) ◽  
pp. 1427-1438 ◽  
Author(s):  
I. Kogelbauer ◽  
W. Loiskandl
Keyword(s):  
Shallow Lake ◽  
Open Water ◽  
Measuring System ◽  
High Water Content ◽  
Sediment Layer ◽  
Soil Physics ◽  
Lake Ecosystems ◽  
Layer Composition

Abstract. Lake sediment characterization, a prerequisite for the vulnerability assessment of lake ecosystems, demands reliable in situ methods for the characterization of the sediment layer composition. A unified characterization of lake sediments within lake ecotopes (open water, open water patches within the reed, and the reed) is still a challenge. Each ecotope is covered by different classical scientific disciplines (hydrography and terrestrial remote sensing to soil physics) with their specific characterization methods. Recently, a complementary tool that bridges the gap between land and hydrographic surveying methods was introduced. It is a non-acoustic device that combines two soil physical sensors (a capacitive sensor and a cone penetrometer) and GNSS-positioning in a measuring system (CSPS). The CSPS enables rapid in situ delineation of water–mud–consolidated lakebed interfaces. The system was successfully applied across ecotopes at the Neusiedler See, a well-mixed shallow lake rich in fine-grained sediments. The geo-referenced vertical CSPS profiles show ecotope-specific layer composition. The effects of wind-induced turbidity, particle size, and electrical conductivity were analysed. The water–mud interface was precisely delineated at the open water due to a persistent high water content gradient, equivalent to a lutocline. The penetration resistance (PR) for open water showed either a shallow and highly compacted consolidated lakebed or a consolidated lakebed with a partially compacted layer above, while in the reed the PR smoothly increased until reaching the deepest penetration depths.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

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