Different light and temperature requirements for survival and growth in three species of Kallymeniaceae (Rhodophyta) from the Mediterranean Sea

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Conxi Rodríguez-Prieto
Keyword(s):  
Laboratory Experiments ◽  
Culture Conditions ◽  
Initial Surface ◽  
Target Species ◽  
Strong Decrease ◽  
Maximum Value ◽  
Determining Factors ◽  
Temperature Requirements ◽  
Survival And Growth ◽  
The Mediterranean

Abstract Laboratory experiments have shown that light and temperature requirements are critical determining factors for thallus survival and growth of three Mediterranean Kallymeniaceae (Rhodophyta): Verlaquea lacerata, Croisettea requienii, and Meredithia microphylla, and explain their current bathymetric and habitat distribution. Verlaquea lacerata is annual and survived more than 1.5 years in culture, while C. requienii and M. microphylla are perennial and survived more than four and nine years in culture, respectively. The maximum survival was observed at 20–50 µmol photon m−2 s−1 and 10 and 12 °C within an 8:16 h light:dark regime for the three species, while a strong decrease in survival was observed at temperatures of 24 and 26 °C, indicating a weak tolerance to warming temperatures in the Mediterranean. The maximum value of the rate of daily marginal extension per initial surface area was similar in the three species: 0.017 day−1 for V. lacerata (10 °C/8:16 h light:dark regime/10 µmol photon m−2 s−1), 0.021 day−1 for C. requienii (18 °C/14:10 h light:dark regime/10 µmol photon m−2 s−1), and 0.017 day−1 for M. microphylla (12 °C/8:16 h light:dark regime/20 µmol photon m−2 s−1). The experiments permitted the establishment of culture conditions for the target species, and the successful culture of marginal fragments indicates the possibility of indefinitely maintaining the species in the laboratory for bioconservation purposes.

Light and temperature requirements for survival, growth and reproduction of the crustose coralline Lithophyllum stictaeforme from the Mediterranean Sea

2016 ◽  
Vol 59 (2-3) ◽  
Author(s):  
Conxi Rodríguez-Prieto
Keyword(s):  
Mediterranean Sea ◽  
Laboratory Experiments ◽  
Temperature Requirements ◽  
The Mediterranean ◽  
Set Up ◽  
Growth And Reproduction

AbstractLaboratory experiments were set up in order to assess light and temperature requirements for survival, growth and reproduction of specimens of

scholarly journals Pots as alternative and sustainable fishing gears in the Mediterranean Sea: an overview

2021 ◽  
Author(s):  
Andrea Petetta ◽  
Massimo Virgili ◽  
Stefano Guicciardi ◽  
Alessandro Lucchetti
Keyword(s):  
Mediterranean Sea ◽  
Early Stage ◽  
Spiny Lobster ◽  
Mesh Size ◽  
Octopus Vulgaris ◽  
Target Species ◽  
Factors Affecting ◽  
Fishing Gears ◽  
Pros And Cons ◽  
The Mediterranean

AbstractStock overexploitation, bycatch, discards and gear impacts on the environment are outstanding issues for Mediterranean fisheries. The adoption of alternative fishing gears is an appealing solution to ensure a more sustainable exploitation of resources. We discuss the pros and cons of pots as alternative gears by reviewing their main designs, spatial distribution and target species in the Mediterranean basin. We assessed the technical factors affecting the catch efficiency of the different pot designs for four target species: spiny lobster, Palinurus elephas; Norway lobster, Nephrops norvegicus; common octopus, Octopus vulgaris and pandalid shrimps, Plesionika spp. We found that pot volume is important to catch Octopus; mesh size to catch Nephrops and Plesionika; entrance surface to catch Octopus, Nephrops and Plesionika; pot shape/colour and entrance shape/position to catch Octopus and Plesionika; and bait type to catch Octopus and Nephrops. The literature review shows that pot fisheries have several considerable advantages over conventional gears, especially in terms of discards, bycatch, seabed impacts (particularly compared with bottom trawls and passive set nets), size and species selectivity, gear depredation, catch quality and gear cost, besides saving time and labour. Disadvantages hampering their wider diffusion include ghost fishing, a low catch of finfish species, the narrow range of species targeted by each pot design and the current early stage of research. These data make a clear case for using pots as alternative gears to traditional ones in the Mediterranean Sea in some areas and seasons to catch certain target species.

Yield and shear of rough interlocked faults: analytical solution and experimental observations

2020 ◽  
Author(s):  
Amir Sagy ◽  
Vladimir Lyakhovsky ◽  
Yossef H. Hatzor
Keyword(s):  
Surface Roughness ◽  
Analytical Solution ◽  
Normal Stress ◽  
Laboratory Experiments ◽  
Three Dimensional ◽  
Elastic Half Space ◽  
Interface Roughness ◽  
Displacement Rate ◽  
Initial Surface ◽  
Surface Geometry

<p>Natural fault surfaces are interlocked, partly cohesive, and display multiscale geometric irregularities. Here we examine the nucleation of deformation and the evolution of shear in such interlocked surfaces using a closed-form analytical solution and a series of laboratory experiments.  The analytical model considers an interlocked interface with multiscale roughness between two linear elastic half-space blocks. The interface geometry is based on three-dimensional fault surfaces imaging. It is represented by a Fourier series and the plane strain solution for the elastic stress distribution is represented as a sum of the constant background stress generated by a uniform far-field loading and perturbations associated with the interface roughness. The model predicts the critical stress necessary for failure and the location of failure nucleation sites across the surface, as function of the initial surface geometry.</p><p>A similar configuration is adopted in laboratory experiments as carbonate blocks with rough interlocked surfaces generated by tensional fracturing are sheared in a servo-controlled direct shear apparatus. Resistance to shear and surface roughness evolution are measured under variable normal stresses, slip distances and slip rates.  We find that the evolution of surface morphology with shear is closely related to the loading configuration. Initially rough, interlocked, surfaces become rougher when normal stress and displacement rate are increased. Under a fixed, relatively low normal stress and fixed displacement rate however, the surfaces become smoother with increasing displacement distance.  </p><p>The shear of the interlocked slip surfaces is associated with volumetric deformation, wear and frictional slip, all of which are typically observed across natural fault zones. We suggest that their intensities and partitioning are strongly affected by the initial surface roughness characteristics, the background stress, and the rate and magnitude of shear displacement. </p>

Bait consumption by, and 1080-based control of, feral pigs in the Mediterranean climatic region of south-western Australia

2007 ◽  
Vol 34 (2) ◽  
pp. 125 ◽  
Author(s):  
Laurie E. Twigg ◽  
Tim Lowe ◽  
Gary Martin
Keyword(s):  
Western Australia ◽  
Sus Scrofa ◽  
Native Species ◽  
Target Species ◽  
Variable Response ◽  
Feral Pigs ◽  
Poison Baiting ◽  
The Mediterranean ◽  
Bait Stations ◽  
Minimal Evidence

The consumption of five non-toxic, grain-based baits, and the effectiveness of the preferred baits when treated with 1080 in reducing pig numbers, were determined for feral pigs (Sus scrofa) in several areas in the Mediterranean agricultural region of Western Australia. Fermented wheat with added blood and bone proved an effective attractant for feral pigs, and for determining areas of pig activity. Wheat and malted barley were the preferred baits, there was a variable response to lupins, and commercial pig pellets were consumed least. Malted barley, barley, and wheat treated with 1080 gave good reductions in pig numbers at the localised scale. Where pigs would eat lupins, 1080-treated lupins were usually effective in reducing pig abundance. In some instances, further evidence of feral pig activity was not seen on several sites for several months after poison-baiting occurred. The addition of a small amount of unpoisoned grain to mask the presence of 1080 did not increase the take of treated bait (P < 0.05). Although finding poisoned pigs was difficult owing to the terrain and the presence of bush remnants, the poisoned pigs found (n = 90) were often within 200 m of active bait stations. 1080-poisoned pigs included both adult (≥25 kg) and non-adult pigs of both sexes. Body mass of these pigs ranged from 4 to 90 kg. In all, 42% of poisoned adults found (n = 50) were 50 kg or more. There was minimal evidence of bait take by non-target species, and, where this occurred, it generally involved the consumption of the fermented wheat attractant by kangaroos (Macropus spp.) and foxes (Vulpes vulpes). Six foxes were known to have been poisoned with 1080-treated grain (4 with malted barley, 2 with wheat). Excluding foxes, no other non-target animals, including native species, were found dead during the intensive searches for poisoned pigs.

scholarly journals Efficiency of fertilizing in sunflower cultivation technology

2021 ◽  
Vol 12 (1) ◽  
pp. 28-38
Author(s):  
L.A. Garbar ◽  
◽  
U. Lishchuk ◽  
N.I. Dovbash ◽  
N.V. Knap ◽  
...  
Keyword(s):  
Growing Season ◽  
Culture Conditions ◽  
Climatic Conditions ◽  
Mineral Fertilizers ◽  
Important Place ◽  
Factor B ◽  
Genetic Potential ◽  
Maximum Value ◽  
Nutritional Conditions ◽  
Selection Of

Nutritional conditions of plants during the growing season is one of the main factors aimed at realizing the genetic potential of sunflower hybrids for growing them in any soil and climatic conditions. Currently, it is important to study the genetic potential of domestic hybrids under different growing conditions in order to identify their competitiveness, which provides an increase in quality and yield of the crop. The use in the production of a significant range of complex microfertilizers on the background of the main fertilizer helps to increase the efficiency of plant use of nutrients of mineral fertilizers and soil, is one of the ways to increase crop yields and quality of agricultural products. Despite the relevance of sunflower as the main oil crop, the technology of its cultivation is not a perfect study, in addition, previous studies often contain conflicting indicators. An important place among the agronomic techniques aimed at increasing crop productivity belongs to the provision of optimal plant nutrition conditions during the growing season. The purpose of the research was to establish the influence of culture conditions and selection of high-yielding hybrids (NK Diamantis, SI Kupava, NK Neoma) for specific soil and climatic conditions through the formation of their productivity. The purpose of the research was to establish the influence of culture conditions and selection of high-yielding hybrids (NK Diamantis, SI Kupava, NK Neoma) for specific soil and climatic conditions through the formation of their productivity. The research was conducted during 2018–2019 on typical low-humus chernozems. The research program provided for the establishment of a three-factor field experiment, which studied hybrids (factor A) fertilizer options (factor B) and foliar fertilization of crops (factor B) in phase 4 and 8 sunflower leaves with Ecoline Bor, Nertus Bor, Bast Bor. The studied sunflower hybrids are NK Diamantis, SI Kupava, NK Neoma. The results of the research revealed significant changes in the diameter of the sunflower inflorescence under the influence of different nutritional conditions created by fertilizer options. The influence of hybrid characteristics also determined this indicator. Plants of the hybrid NK Diamantis formed baskets, the diameters of which varied from 17.6 to 21.2 cm, SI Kupava - from 18.8 to 22.1 cm, NK Neoma – from 17.2 to 21.6 cm. The maximum value was obtained on variant with the introduction of N36P56K108S28 + N23 + Ecoline Boron (phase 4 and 8 leaves) in plants of the hybrid SI Kupava, which corresponded to 22.1 cm. The weight of 1 000 achenes belonging to genetically determined traits of culture, in plants of the hybrid NK Diamantis, depending on the fertilizer variant varied from 59.3 to 62.3 g, SI Kupava from 69.8 to 74.0 g, NK Neoma from 68.8 to 72.6 g. The maximum value was provided by the variant with the use of N36P56K108S28 + N23 + Ecoline Boron (phase 4 and 8 leaves). Studies have shown that the most productive was the hybrid SI Kupava with the maximum yield on the variant with the use of N36P56K108S28 + N23 + Ecoline Boron (in phase 4 and 8 leaves of 1 l / ha) – 3.46 t per ha.

Light and temperature requirements for germination in the Mediterranean shrub Lavandula stoechas (Lamiaceae)

Plant Biology ◽  
2021 ◽  
Author(s):  
F. Ghaderi‐Far ◽  
Z. L. Coşgun ◽  
C. Ü. Değirmenci ◽  
İ. Tüysüz ◽  
C. Ülgen ◽  
...  
Keyword(s):  
Lavandula Stoechas ◽  
Temperature Requirements ◽  
The Mediterranean ◽  
Mediterranean Shrub

Florogenesis of the Mediterranean geophyte Narcissus tazetta and temperature requirements for flower initiation and differentiation

2009 ◽  
Vol 120 (1) ◽  
pp. 138-142 ◽  
Author(s):  
T. Noy-Porat ◽  
M.A. Flaishman ◽  
A. Eshel ◽  
D. Sandler-Ziv ◽  
R. Kamenetsky
Keyword(s):  
Flower Initiation ◽  
Narcissus Tazetta ◽  
Temperature Requirements ◽  
The Mediterranean

scholarly journals EVALUACION DE DIFERENTES DENSIDADES DE LA MICROALGA NANNOCHLOROPSIS OCULATA COMO ALIMENTO PARA ARTEMIA

2016 ◽  
Vol 23 ◽  
Author(s):  
Rafael Tizol Correa
Keyword(s):  
Growth Rate ◽  
Correlation Matrix ◽  
Brine Shrimp ◽  
Laboratory Experiments ◽  
Food Source ◽  
Nannochloropsis Oculata ◽  
Shrimp Culture ◽  
Cellular Concentration ◽  
Survival And Growth

Laboratory experiments were carried out to determine the possibility of using the microalgae Nannochloropsis oculata as a food source for brine shirmp. Among the range concentrations studied (3 x 105 to 14 x 105 cells/ml), 12 x 105 cells/ml offered the best results of survival and growth rate and it is recommended as the most effective. From correlation matrix, high values (r > 0.90; a = 0.05) were obtained for the relation of microalgae concentration and survival, growth rate and the variation of average lenght. The minimum cellular concentration of microalgae which is necessary for brine shrimp culture is 5.6 x 105 cells/ml.

scholarly journals Nutrient Regulation of Relative Dominance of Cylindrospermopsin-Producing and Non-cylindrospermopsin-Producing Raphidiopsis raciborskii

2021 ◽  
Vol 12 ◽  
Author(s):  
Lamei Lei ◽  
Minting Lei ◽  
Nan Cheng ◽  
Zhijiang Chen ◽  
Lijuan Xiao ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Field Survey ◽  
Global Scale ◽  
Field Investigation ◽  
Culture Conditions ◽  
Cylindrospermopsis Raciborskii ◽  
Nutrient Regulation ◽  
Relative Dominance ◽  
The Relationship ◽  
Natural Water Bodies

Raphidiopsis raciborskii (previously Cylindrospermopsis raciborskii) can produce cylindrospermopsin (CYN) which is of great concern due to its considerable toxicity to human and animals. Its CYN-producing (toxic) and non-CYN-producing (non-toxic) strains co-exist commonly in natural water bodies, while how their relative dominance is regulated has not been addressed. In this study, we combined field investigation with laboratory experiments to assessed the relationship between toxic and non-toxic R. raciborskii abundances under different nutrient levels. The rpoC1- and cyrJ-based qPCR was applied for quantifying total and toxic R. raciborskii abundances, respectively. The field survey showed that toxic R. raciborskii was detected in 97 of 115 reservoirs where its proportion ranged from 0.3% to 39.7% within the R. raciborskii population. Both total and toxic R. raciborskii abundances increased significantly with trophic level of these reservoirs, consistent with our monoculture and co-culture experiments showing in an increase in R. raciborskii growth with increasing nitrogen (N) or phosphorus (P) concentrations. In the monoculture experiments, growth rates of non-toxic and toxic strains from Australia or China were not significantly different under the same culture conditions. On the other hand, in the co-culture experiments, the toxic strains displayed a significantly faster growth than non-toxic strains under nutrient-replete conditions, resulting in an obvious shift toward the dominance by toxic strains from day 3 to the end of the experiments, regardless of the strain originating from Australia or China. The reverse was found under N- or P-limited conditions. Our results indicated that the toxic strains of R. raciborskii have a competitive advantage relative to the non-toxic strains in a more eutrophic world. In parallel to an increase in dominance, both toxic strains grown in the mixed population significantly increased CYN production under nutrient-replete conditions as compared to nutrient-limited conditions, suggesting that CYN may be of significance for ecological advantage of toxic R. raciborskii. These results highlight the importance of nutrient availability in regulating abundances and strain dominance of two genotypes of R. raciborskii. Our findings demonstrated that elevated nutrients would favor the growth of CYN-producing R. raciborskii and CYN production, leading to more blooms with higher toxicity at global scale.

scholarly journals Suitability of Substrate for Laboratory Studies with the Subterranean Termite Reticulitermes grassei (Clément) (Isoptera: Rhinotermitidae)

Sociobiology ◽  
2016 ◽  
Vol 63 (2) ◽  
pp. 855 ◽  
Author(s):  
Patricia Gallardo ◽  
Ana M Cardenas ◽  
Raquel Murillo
Keyword(s):  
Survival Rate ◽  
Laboratory Experiments ◽  
Subterranean Termite ◽  
Laboratory Studies ◽  
Time Duration ◽  
The Mediterranean ◽  
Short Time

Two substrates, sand and vermiculite, were tested in rearing laboratory experiments with Reticulitermes grassei at different culture periods (2, 4 and 6 weeks). Although information is available regarding procedures to keep species of Reticulitermes in lab, none of them is referred to the Mediterranean termite R. grassei. The suitability of substratum was assessed in terms of survival of termites. The highest survival rate was in the experiment with sand and short-time duration, but after six weeks exposure, survival was significantly lower on this substrate. These differences among substrates were not significant for any of the treatments.

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