Growth and reproduction of Donax trunculus from the Gulf of Annaba (Northeast Algeria) in relation to environmental conditions

2020 ◽  
Vol 27 (33) ◽  
pp. 41656-41667
Author(s):  
Amel Hamdani ◽  
Noureddine Soltani ◽  
Nedjoua Zaidi
Keyword(s):  
Environmental Conditions ◽  
Donax Trunculus ◽  
Growth And Reproduction

On the distribution of the Arctic endemic alga Laminaria solidungula (Laminariales) in the White Sea

2021 ◽  
Vol 55 (2) ◽  
pp. 325-333
Author(s):  
T. A. Mikhaylova
Keyword(s):  
Global Warming ◽  
Environmental Conditions ◽  
Brown Alga ◽  
White Sea ◽  
The Arctic ◽  
The White Sea ◽  
Anatomical Features ◽  
Growth And Reproduction

The morphological and anatomical features of the specimens of the brown alga Laminaria solidungula collected in the White Sea are provided. Environmental conditions for the growth and reproduction of this species in the White Sea are analyzed. The probable timing of penetration of this species into the White Sea and possible scenarios of changes in its distribution in response to global warming are discussed.

scholarly journals Genome analyses of a placozoan rickettsial endosymbiont show a combination of mutualistic and parasitic traits

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kai Kamm ◽  
Hans-Jürgen Osigus ◽  
Peter F. Stadler ◽  
Rob DeSalle ◽  
Bernd Schierwater
Keyword(s):  
Amino Acids ◽  
Environmental Conditions ◽  
Metabolic Pathways ◽  
Essential Amino Acids ◽  
Intracellular Bacteria ◽  
The Novel ◽  
Symbiotic Relationships ◽  
Genome Analyses ◽  
Growth And Reproduction

AbstractSymbiotic relationships between eukaryotic hosts and bacteria range from parasitism to mutualism and may deeply influence both partners’ fitness. The presence of intracellular bacteria in the metazoan phylum Placozoa has been reported several times, but without any knowledge about the nature of this relationship and possible implications for the placozoan holobiont. This information may be of crucial significance since little is known about placozoan ecology and how different species adapt to different environmental conditions, despite being almost invariable at the morphological level. We here report on the novel genome of the rickettsial endosymbiont of Trichoplax sp. H2 (strain “Panama”). The combination of eliminated and retained metabolic pathways of the bacterium indicates a potential for a mutualistic as well as for a parasitic relationship, whose outcome could depend on the environmental context. In particular we show that the endosymbiont is dependent on the host for growth and reproduction and that the latter could benefit from a supply with essential amino acids and important cofactors. These findings call for further studies to clarify the actual benefit for the placozoan host and to investigate a possible role of the endosymbiont for ecological separation between placozoan species.

Modeling growth and reproduction of chilipepper rockfish under variable environmental conditions

2011 ◽  
Vol 109 (1) ◽  
pp. 187-200 ◽  
Author(s):  
Chris J. Harvey ◽  
John C. Field ◽  
Sabrina G. Beyer ◽  
Susan M. Sogard
Keyword(s):  
Environmental Conditions ◽  
Growth And Reproduction ◽  
Modeling Growth

GNOMONIA FRUCTICOLA ON STRAWBERRY

1954 ◽  
Vol 32 (1) ◽  
pp. 172-181 ◽  
Author(s):  
A. T. Bolton
Keyword(s):  
Environmental Conditions ◽  
Leaf Spot ◽  
Leaf Blight ◽  
Leaf Scorch ◽  
Vascular Elements ◽  
High Concentrations ◽  
Growth And Reproduction

Gnomonia fructicola (Arnaud) Fall was isolated from strawberries growing in various localities in Ontario and Quebec. This fungus was found to be capable of causing serious damage to strawberries under certain environmental conditions. The disease occurs on fruits, peduncles, and leaf petioles and blades. On the leaves, the first symptoms are numerous pin-point lesions which enlarge and coalesce, and finally cover large areas of the blades or entirely girdle the petioles. The fungus was found to enter the stomata of artificially inoculated leaf blades. In the host, the fungus tends to follow the vascular elements along which the pycnidia and perithecia are usually formed. Pathogenicity of G. fructicola was compared with that of leaf blight, leaf scorch, and leaf spot of the strawberry. It was demonstrated that, under the conditions described, it was capable of causing as much damage as any of the three diseases. The results obtained from nutritional experiments indicate that high concentrations of dextrose suppress, whereas those of starch, cellulose, and pectin favor the growth and reproduction of G. fructicola.

Percid Habitat: The River Analogy

1977 ◽  
Vol 34 (10) ◽  
pp. 1936-1940 ◽  
Author(s):  
James F. Kitchell ◽  
Murray G. Johnson ◽  
C. Kenneth Minns ◽  
Kenneth H. Loftus ◽  
Lorne Greig ◽  
...  
Keyword(s):  
Key Words ◽  
Environmental Conditions ◽  
Current Velocity ◽  
Perca Flavescens ◽  
Light Penetration ◽  
Habitat Conditions ◽  
Reproductive Patterns ◽  
Evolutionary Origins ◽  
Reduced Light ◽  
Growth And Reproduction

We propose that the optimum habitat of the percid fishes Perca flavescens, P. fluviatilis, Stizostedton vitreum vitreum, and S. lucioperca in lakes may be defined by the littoral and sublittoral environmental conditions equivalent to those in large, temperate rivers. Analogous habitat conditions include sand or gravel substrate, low current velocity, reduced light penetration (Stizostedion spp. only), temperatures optimal for growth and reproduction, and well-oxygenated spawning substrates. The species' evolutionary origins and reproductive patterns also reflect their riverine ancestral habitat. Evidence in support of the hypothesis is derived from the diversity of papers contributed to the PERCIS Symposium. Key words: Percidae, habitat, theory, Perca, Stizostedion

Emergence, Growth, and Reproduction of Horse Purslane (Trianthema portulacastrum) as Influenced by Environmental Conditions

Weed Science ◽  
1986 ◽  
Vol 34 (4) ◽  
pp. 516-519 ◽  
Author(s):  
R. S. Balyan ◽  
V. M. Bhan
Keyword(s):  
Environmental Conditions ◽  
Dry Matter ◽  
Seedling Emergence ◽  
Growth Stages ◽  
Plant Seeds ◽  
Trianthema Portulacastrum ◽  
Sowing Dates ◽  
Vigorous Growth ◽  
Number Of Branches ◽  
Growth And Reproduction

The effect of environmental conditions on horse purslane (Trianthema portulacastrum L. # TRTPO) emergence, growth, and reproduction was studied by sowing seeds on June 10, June 30, July 20, August 10, and August 30, 1984. The first three seeding dates resulted in significantly higher seedling emergence than the August 30 date. Leaf number, leaf area, dry matter, and number of branches per plant at the peak growth stages of this weed were significantly higher for the July 20 sowing than for the other sowing dates, followed closely by the June 30 sowing. Similarly, number of nodes per plant, seeds per plant, and seed weight per plant were also significantly higher for the July 20 sowing, followed closely by the June 30 sowing. Phenological behavior of the plants indicate that: a) maximum seedling emergence takes place during June and July, b) rapid and vigorous growth occurs during July and August (rainy season) when conditions for growth are optimum, and c) production of flowers and seeds starts 20 to 30 days after sowing.

Vibration Isolator System for Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 182-183
Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Magnetic Fields ◽  
Environmental Conditions ◽  
Vibration Isolator ◽  
Air Conditioners ◽  
Vibration Isolators ◽  
Large Size ◽  
Electron Microscopes

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.

Sign in / Sign up

Export Citation Format

Share Document