Effects Of Different Salinities Research Articles

Effect of different salinities on the susceptibility of striped catfish (Pangasianodon hy-pophthalmus) to Aeromonas hydrophila bacteria causing hemorrhagic disease

This study was conducted to determine the effect of different salinities on striped catfish (Pangasianodon hypophthalmus) susceptibility to hemorrhagic disease causing by Aeromonas hydrophila bacteria. The experiment was set up in plastic tanks at various salinities (0, 3, 5, 8, 11 and 14‰). Experimental fish (about 25 ± 0.8g/fish) were challenged with A. hydrophila bacteria by intramuscular injection. After infection, the mortality and disease signs were recorded for 14 days. At the same time, bacteria re-isolation and re-identification were carried out with infected fish samples that displayed signs of lethargy, disorientation, hemorrhagic in anal, peritoneal sinus and spleen. Recorded cumulative mortality after 14 days was 86.7% at salinity 0‰ and 8.3% and 11.7% at salinities 11 and 14‰, respectively. At higher salinity, striped catfish is less susceptible to A. hydrophila bacteria than at lower salinities.

Effects of salinity on growth performance, survival rate, digestive enzyme activities and physiological parameters of striped catfish (Pangasianodon hypophthalmus) at larval stage

The present study was to investigate the effects of different salinities (0 (control), 3, 6, 9, 12, 15‰) in striped catfish (Pangasianodon hypophthalmus) at larvae stage. Four-hundred individuals were randomly distributed to each 500-L composite tank (containing 250-L water) in triplicates. After 60 days, fish was sampled to determine survival rate, growth performance, hematological parameters, stress response indicators, and enzymatic activities. The results showed that the survival rate was highest in 6‰ (60.9%) and lowest in 15‰ (1.25%) (p<0.05). Fish exposed to salinities from 0 to 9‰ showed an increasing trend in growth. The osmolality of fish reared in 9 and 12‰ was significantly higher than that in the lower salinities (p<0.05). Similarly, concentrations of Na+, K+, and Cl- increased remarkably at high salinities. Chymotrypsin and trypsin activities were reduced by increased salinities (p<0.05), which were lowest at 15‰ (69.2±2.46 U/min/mg protein and 1.46±0.01 mU/min/mg protein, respectively). Stress indicators such as glucose and cortisol concentrations were not significantly depended on the salinity in the range of 0 to 12‰. Striped catfish larvae showed an adaptable response to high salinity and the appropriate salinity range for larvae rearing was below 6‰.

Growth, osmoregulatory and hypothalamic–pituitary–somatotropic (HPS) axis response of the juvenile largemouth bass (Micropterus salmoides), reared under different salinities

A 40 day experiment was conducted to investigate the effects of different salinities (0, 5 and 10 ppt) on the growth, osmoregulatory and hypothalamic–pituitary–somatotropic (HPS) axis response of juvenile largemouth bass (Micropterus salmoides). At the same time, two extra groups salinities (8 and 9 ppt) were used to explore the threshold of osmoregulation in M. salmoides to salinity stress. The survival were 94.45 %, 98.15 % and 32.00 % in 0, 5, 10 ppt, respectively. According the final body weight, specific growth rate (SGR), feed conversion ratio (FCR), condition factor (K) and chemical composition of muscle, largemouth bass should not be cultured at or above 10 ppt and 5 ppt is better than 0 ppt. The results found that the content of serum prolactin (PRL) and cortisol (COR) were no significant differences between groups of the 0, 5, 8, 9 and 10 ppt. Compared with the control group (0 ppt), the serum thyroxine (T4) content of 8 and 9 ppt groups decreased significantly and the serum triiodothyronine (T3) content all decreased significantly. Serum osmolality increased with increasing salinity. Na+-K+-ATP (NKA) and Ca2+-Mg2+-ATP (CMA) activities in the gills of largemouth bass at 0, 5, 8, 9 and 10 ppt showed tendency of ascend at first and descend at last, among which the activities in 10 ppt were significantly lowest. Gene expression of hepatic growth hormone (GH) at 10 ppt was highest. Meanwhile, insulin-like growth factor-I (IGF-I) expression at salinities of 8, 9 and 10 ppt were significantly higher than those at 0 and 5 ppt. Taken together, the findings of this study provide guidance for the practical rearing of largemouth bass in saline waters and contribute to research on stress physiology.

Effects of salinity on the simultaneous anammox and denitrification process: performance, sludge morphology and shifts in microbial communities.

In this study, the long-term effects of different salinities on the performance, sludge morphology and shifts in microbial communities were studied in a simultaneous anammox and denitrification (SAD) process at a C/N ratio of 0.5. Stable nitrogen removal efficiencies of 86.96 and 84.58% and nitrogen removal rates of 0.95 and 0.93 kg (m3 d)−1 could be achieved under low (25 mmol l−1) and moderate (50 mmol l−1) salinity, respectively. However, the performance collapsed when the system was exposed to high salinity (100 mmol l−1). The content of extracellular polymeric substances increased as salinity increased, which resulted in larger sizes of granular sludge under low and moderate salinities. Nevertheless, high salinity shock disintegrated granular sludge, thereby decreasing the average granule size. The Illumina-Miseq sequencing results revealed that Candidatus Jettenia was the sole salinity-tolerant AnAOB genus during the entire operation, whereas the main denitrification bacterial genera shifted from Denitrisoma under low salinity to Denitrisoma, Thauera and Ignavibacterium under high salinity. The results of this study provide a comprehensive and practical evaluation of the SAD process for organic nitrogen-rich saline wastewater treatment.

Growth and metabolic responses of orange spotted grouper Epinephelus coioides (Hamilton, 1822) fingerlings at different salinity regimes

A feeding trial was conducted for 60 days to delineate the effect of different salinities on growth and metabolic responses in fingerlings of orange spotted grouper Epinephelus coioides (Hamilton, 1822). The grouper fingerlings (N=1050; Av. wt. 2.0±0.01 g) were distributed equally into seven treatments of varying salinities viz., 5±1‰ (T1), 10±1‰ (T2), 15±1‰ (T3), 20±1‰ (T4), 25±1‰ (T5), 30±1‰ (T6) and 35±1‰ (T7) in triplicates. Fingerlings were fed with commercial diet containing 45% crude protein and 10% lipid. Results from the experiment concluded that growth performance of fingerlings of T4 group was better with minimum metabolic enzyme activity. The liver glycogen was significantly lower (p<0.05) in T4 group. Oxygen consumption rate (OCR) was recorded maximum at 15±1‰ and was significantly reduced for the fingerlings maintained at high salinity (p<0.05) from 20±1 to 35±1‰. Orange spotted grouper fingerlings maintained at salinity of 20±1‰ confirmed that, the animal spent less metabolic energy for maintaining the ionic balance at this optimum salinity compared to other salinities and it was reflected in better growth performance with minimum OCR and metabolic enzyme activities.

Effect of Irrigation Waters in Different Salinity Levels on Crop Yield and Energy Use in Greenhouse Tomato Production in Turkey: A Case Study in Kırklareli Province

This study was carried out in a quonset type plastic covered unheated greenhouse on the lands of Atatürk Soil Water and Agricultural Meteorology Institute in Kırklareli, Turkey. In the study, the effect of different salinity and irrigation water levels which were applied to tomato plant, irrigated by drip irrigation in greenhouse, on yield and energy use efficiency was evaluated and the optimum irrigation application was determined. In the study, ‘Swanson F1’ type tomato was grown as plant material. The trial was carried out on 36 parcels with three repetitions according to split plots trial design and four different irrigation water salinity levels were on main plots and three irrigation levels were on sub plots. The best result was obtained from T1S2 subject in terms of yield and energy use efficiency. The average yield was determined as 109060 kg ha-1 and energy output/input ratio, energy productivity and specific energy were found as 1.51, 1.89 kg MJ-1 and 0.53 MJ kg-1 in T1S2 subject, respectively. It was concluded that the optimum method should be on low salinity level and the irrigation water application should be on the level in order to bring the current moisture level to the field capacity.

Characterization and evaluation of a natural surfactant extracted from Soapwort plant for alkali-surfactant-polymer (ASP) slug injection into sandstone oil reservoirs

Different types of surfactants are used in the chemical water flooding process in oil reservoirs with the aim of water-oil interfacial tension (IFT) reduction. Recently, much attention is paid to the use of natural surfactants such as plant extracts in enhanced oil recovery (EOR) process. However, some characteristics of these surfactants, such as their efficiencies in achieving the appropriate values of IFT, adaptability to different salinities and their temperature stability at reservoir conditions, must be acceptable. In the current work, a non-ionic surfactant was extracted from Soapwort plant under ultrasonic extraction and saponin purification processes. Proton Nuclear Magnetic Resonance (1HNMR), Fourier Transform Infrared Spectroscopy (FTIR) and Thermal Gravimetric Analysis (TGA) techniques were used to investigate the natural surfactant characteristics. The pendant drop surface tension tests were used to estimate the critical micelle concentration (CMC) of this natural surfactant. Finally, the application of the surfactant in the EOR process was demonstrated using the experiments of water-oil IFT, contact angle and alkali-surfactant-polymer (ASP) slug injection. The effects of different salinities on surfactant performance in reducing interfacial tension and contact angle were also investigated. Based on the results, the CMC of the surfactant was obtained at 2250 ppm and at 80 °C. The water-oil IFT at surfactant CMC was 0.832 mN/m, which decreased by 0.541, 0.714 and 0.775 mN/m at the optimal salinity of the diluted formation water, MgCl2 and NaCl solutions, respectively. The IFT was decreased by 0.047, 0.078 and 0.096 mN/m at the optimal concentration of NaOH, Na2CO3 and NaHCO3 alkalis, respectively. Sandstone wettability was altered from hydrophobicity to hydrophilicity by surfactant solution at CMC and the contact angle was decreased from 124.42° to 45.94°. The contact angle at CMC was decreased by 35.12°, 38.44° and 43.62° at the optimal concentration of FW, MgCl2 and NaCl, respectively and eventually, oil recovery was achieved by 32.1% by tertiary ASP slug injection containing surfactant at CMC, optimal saline, optimal NaOH alkali concentration and 1000 ppm of partially hydrolyzed polyacrylamide (PHPA). Surfactants are used in various applications in the oil industry. The focus of this study was on the use of the plant surfactant in EOR by ASP injection process. However, other applications of this surfactant for injection in various scenarios based on chemical water in EOR process can be developed.

Assessing four different macroscopic water uptake models for maize plant (ZEA mays L.) under salinity stress*

AbstractThe global shortage of fresh water in arid/semi‐arid regions has inevitably led to the use of unconventional sources of water. One of the strategies for managing saline water consumption is by using simulator models that can help in understanding the physiological response of crops. In this study the number of germinated seeds, shoot fresh weight and plant leaf area index as three of the main parameters of the vegetative stage of maize plants were investigated. In order to quantify the effect of different salinities on vegetative growth parameters, the macroscopic models of Homaee et al., Dirksen et al., van Genuchten and Hoffman and Maas and Hoffman were tested. The fitting of different models to measured data of germinated seeds showed that the Maas and Hoffman model was superior over the other three models with r and NSE values of 0.87 and 0.79, respectively. Similarly, the model of Homaee et al. with the values of r = 0.98 and NSE = 0.89 was the best model for the maize fresh weight variable. Finally, for the leaf area index variable, the van Genuchten and Hoffman model having values of r = 0.95 and NSE = 0.91 was able to provide a better estimate than the other models.

Effects of salinity on the ions important and sodium‐potassium ATPase in osmoregulation, cortisol, amino acids, digestive and immune enzymes in Scylla paramamosain during indoor overwintering

Overwintering is an important part of the conservation of Scylla paramamosain, and salinity has an important effect on the conservation of S. paramamosain during overwintering. Three salinities (4‰, 12‰ and 25‰) were selected as the overwintering salinities to reveal the effects of different salinities on the relevant important ions in osmotic pressure regulation, plasma cortisol, digestive enzymes, immune enzymes and amino acids of S. paramamosain during indoor overwintering. Results indicated that after overwintering, Cl-, Na+ and the osmotic pressure of serum have the highest salinity at 25‰, and the lowest salinity at 4‰. Na+/K+-ATPase activity and cortisol were found to increase with decreasing salinity. The activity of digestive and immune enzymes was highest at 25‰, and was the lowest at 4‰. The amount of total amino acids (TAA), umami amino acids (UAA) and essential amino acids (EAA) in 25‰ were significantly higher than in 4‰ and 12‰. After overwintering, the essential amino acid index (EAAI) in the salinity range of 12–25‰ was 54.04–59.00, compared to 48.56–54.04 in the salinity range of 4–12‰. As a result, S. paramamosain at 25‰ had higher digestion and immunity than at 4‰ and 12‰, due to requiring more energy for osmotic pressure adjustment. In addition, S. paramamosain at 25‰ had the best meat quality. The results of this study are helpful for aquaculture production for indoor overwintering of S. paramamosain.

Growth study under combined effects of temperature, pH and salinity and transcriptome analysis revealed adaptations of Aspergillus terreus NTOU4989 to the extreme conditions at Kueishan Island Hydrothermal Vent Field, Taiwan.

A high diversity of fungi was discovered on various substrates collected at the marine shallow-water Kueishan Island Hydrothermal Vent Field, Taiwan, using culture and metabarcoding methods but whether these fungi can grow and play an active role in such an extreme environment is unknown. We investigated the combined effects of different salinity, temperature and pH on growth of ten fungi (in the genera Aspergillus, Penicillium, Fodinomyces, Microascus, Trichoderma, Verticillium) isolated from the sediment and the vent crab Xenograpsus testudinatus. The growth responses of the tested fungi could be referred to three groups: (1) wide pH, salinity and temperature ranges, (2) salinity-dependent and temperature-sensitive, and (3) temperature-tolerant. Aspergillus terreus NTOU4989 was the only fungus which showed growth at 45 °C, pH 3 and 30 ‰ salinity, and might be active near the vents. We also carried out a transcriptome analysis to understand the molecular adaptations of A. terreus NTOU4989 under these extreme conditions. Data revealed that stress-related genes were differentially expressed at high temperature (45 °C); for instance, mannitol biosynthetic genes were up-regulated while glutathione S-transferase and amino acid oxidase genes down-regulated in response to high temperature. On the other hand, hydrogen ion transmembrane transport genes and phenylalanine ammonia lyase were up-regulated while pH-response transcription factor was down-regulated at pH 3, a relative acidic environment. However, genes related to salt tolerance, such as glycerol lipid metabolism and mitogen-activated protein kinase, were up-regulated in both conditions, possibly related to maintaining water homeostasis. The results of this study revealed the genetic evidence of adaptation in A. terreus NTOU4989 to changes of environmental conditions.

Differential effects of soluble salts on seed germination of Marrubium vulgare L.

In Mediterranean basin and western Asia, Marrubium vulgare L. (Lamiaceae) presents a great demand in therapeutic and folk-medicinal usages. However, data about the seed ecology of this medicinally important shrub is scarce. Therefore, the knowledge of its germination requirements is needed for plant establishment in new potential areas. In present work, the effect of different salinities (NaCl, Na2SO4, CaCl2 and MgCl2) on the germination percentage (GP), germination velocity (GV) and salinity tolerance index (STI) of M. vulgare was studied. A complete randomized design was performed in which four salinity levels (0, 50, 100 and 150 mM) were used. The experiment was conducted in programmed incubator with light/darkness temperatures of 25 °C/15 °C at a 12–h photoperiod. The results revealed that seeds of M. vulgare were non–dormant and exhibited highest GP under non–saline conditions (∼ 95 %). Both GP and GV decreased significantly with increasing salinity irrespective of applied salt types. The inhibition of germination by soluble salts was in the following order: Na2SO4 > MgCl2 > CaCl2 > NaCl. The salinity tolerance index (STI) displayed that salinity tolerance of M. vulgare was highest for NaCl and lowest for Na2SO4 at the same concentration among the four saline solutions. These findings suggest that M. vulgare may be considered as a new moderate salt–tolerant species and a promising medicinal shrub for saline soil rehabilitation.

Growth performance of Alexandrium catenella from the Chilean fjords under different environmental drivers: plasticity as a response to a highly variable environment

AbstractAlexandrium catenella, the main species associated with harmful algal blooms, has progressively increased its distribution through one of the most extensive and highly variable fjord systems in the world. In order to understand this successful expansion, we evaluated the effects of different salinities, light intensity, temperatures, nitrogen (N) forms and nitrogen/phosphate (N:P) ratio levels on the growth performance, using clones isolated from different locations across its wide geographic distribution. Results showed that the growth responses were plastic and, in some cases, different reaction norms among clones were observed. Despite plasticity, the optimal growth of A. catenella (i.e. highest growth rate and highest maximal cells density) was reached within a narrow thermal range (12–15°C), while salinity (20–30 PSU) and light intensity (20–120 μmol m−2 s−1) ranges were wider. These results are partially consistent with the highest cell densities recorded in the field. Furthermore, optimal growth was reached using reduced forms of nitrogen (i.e. urea and NH4+) and in unbalanced N:P ratios (18:1 and 30:1). These characteristics likely allow A. catenella to grow in highly variable environmental conditions and might partly explain the recent expansion of this species.

Effects of salinity on growth, nutrient composition, fatty acid composition and energy metabolism ofScylla paramamosainduring indoor overwintering

Three salinities (4‰, 12‰ and 25‰) were selected to determine the effects of different salinities on the growth, survival, nutrition and energy metabolism of Scylla paramamosain during indoor overwintering. Growth performance (survival rate, condition factor, hepatopancreatic index, weight gain rate and specific growth rate), nutrient composition (ash, moisture, crude fat, crude protein and total nitrogen), fatty acids, energy metabolites (glycogen, glucose, triglycerides, cholesterol and lactic acid) and energy metabolic enzymes (hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase) were measured and calculated. The results showed that S. paramamosain exhibited the best growth and survival at 25‰ and worst at 4‰ after overwintering. In addition to consuming crude fat, excess protein was also broken down to provide energy in the 4‰ and 12‰ groups. The content of unsaturated fatty acids in the 25‰ group was higher after overwintering. Glycogen and glucose consumption and triglycerides, cholesterol and lactic acid production were lowest in the 25‰ group. The activity of hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase was highest in the 4‰ group and lowest in the 25‰ group. The activity of hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase in the hepatopancreas was higher than in the muscle. In conclusion, S. paramamosain uses less energy, has more unsaturated fatty acids and has a higher survival rate at a salinity of 25‰ after overwintering. The results of this study provide helpful information the indoor overwintering S. paramamosain in aquaculture production systems.

Physiological and biochemical responses of different shell color strains of Manila clam to low salinity challenges

Salinity is one of the important factors affecting geographic distribution, reproduction and physiological processes of marine and estuarine organisms. In this study, the effects of different salinity on the physiological and biochemical response were evaluated in three shell color strains and wild population of Ruditapes philippinarum by measuring superoxide dismutase (SOD), catalase (CAT), and α-amylase enzyme activity. With decreasing salinity, the SOD activity of wild clams, Zebra strain and White zebra strain increased firstly and in wild clam it decrease later, while the SOD activity of white clams firstly decreased and then increased. With decreasing salinity, the CAT activity of wild clams decreased first and then increased, while the zebra clam and white zebra clams increased first then decreased and white clams decreased The amylase in different strains of clams showed the same trend with decreasing first and then increased. The levels of amylase activities firstly decreased and then increased with the decrease of salinity in Manila clams. A similar trend of amylase activities were observed in different shell color strains and wild population of Manila clam. Our results may be used to optimize the salinity conditions for optimal growth and survival of R. philippinarum and to provide basic information for aquaculture management of this economically important bivalve species.

EFFECT OF SALINITY ON THE SURVIVAL, GROWTH AND IMMUNITY RATE OF JUVENILE SEA CUCUMBERS (Holothuria scabra)

Sea cucumber (Holothuria scabra) is important species as food and medicine especially for Chinese market. It  is a stenohaline and osmoconforming organism with a low level of tolerance to salinity change. Salinity of the medium is one of the environmental factors that affect the physiology and survival of juvenile sea cucumbers. This study was aimed at assessing the effect of different salinities on the growth, survival and immunity rate of juvenile sea cucumbers (Holothuria scabra) and also determining the suitable salinity level for the optimal growth, survival and immunity rate of the sea cucumbers. This experiment  used a completely randomized design with 5 salinity treatments: 24, 29, 34, 39, and 44 ppt with 3 replications using fifteen30 L-fiber glass tanks. The juvenile sea cucumbers measured 4.4 ± 0.2 cm in total length and 5.6 ± 0.3 g in body weight. The juveniles were raised at 15 individuals/tank, fed with cultured fresh benthos once a day in the afternoon. Coelomate was taken from the sea cucumber juveniles from each tank  and used to determinie the immunity rate and also for the osmolality. The data were analyzed using ANOVA followed by Tukey’s test at 5% level of significance. The salinity of the medium significantly affected (P < 0.05) the growth, survival rate and immunity rate of sea cucumber juveniles. The 24 - 34 ppt salinity can support survival rate up to 100%, high growth (6.47 – 7.10 g) and immunity rate (27 – 76 x 104phagocytic cell/mL), while the 44 ppt salinity has resulted in not only a low survival rate (55.6%), but also had a bad effect on osmolality (303 ± 3.5 mOs-mol kg-1), growth (3.12 ± 0.34 g), and immunity (209 x 104 phagocytic cell/mL).

Effect of different salinities on breeding and larval development of common carp, Cyprinus carpio (Linnaeus, 1758) in inland saline groundwater

A 90 days experiment was conducted to study the effect of different salinities (0, 5, 10 and 15 ppt) on breeding and larvae development of Cyprinus carpio using inland saline groundwater (ISGW). At the end of the experiment, average weight of the matured brooders were 370 ± 20 g, 342 ± 26 g, 275 ± 15 g, 167.5 ± 17.50 g at the salinities of 0, 5, 10 and 15 ppt, respectively. Among different salinities, relatively high gonad weight, fecundity, sperm motility, fertilization rate, embryonic and larval development was observed at the salinities of 0 and 5 ppt. The results showed that the stripping response, latency period, fertilization, and hatching rate were significantly (P < 0.05) reduced at the salinity of 15 ppt. The percentage of larvae survival were 69.40 ± 1.76, 74.28 ± 2.22, 49.98 ± 2.04 and 28.78 ± 5.34 at the salinities of 0, 5, 10 and 15 ppt, respectively. Long hatching duration (68–70 h) and high levels of larvae deformity (71.21 ± 5.34%) was also observed at 15 ppt. Thus, it can be concluded that 5 ppt of ISGW can provide the best results for the production of C. carpio seed and could be useful in developing a hatchery technology for C. carpio.

Effect of Salinity Difference on Lipid Content from Chaetoceros muelleri on Continuous Reactors

Chaetoceros muelleri is a microalgae class of Bacillariophyta (diatom) which is generally only used as feeds for fishes and shellfish larvae. Nevertheless, the biochemical content of this species is quite high and has the potential to be developed. This research aims to explain the effect of different salinity on the growth and lipid content of Chaetoceros muelleri cultured in a continuous photobioreactor. This research was carried out in August 2018 - February 2019. The research was conducted at the Laboratory of Marine Microbiology and the Laboratory of Bioprocess and Bioprospection of Natural Materials, Faculty of Fisheries and Marine Sciences, Padjadjaran University. The samples of Chaetoceros muelleri isolates were obtained from the Jepara Brackish Water Aquaculture Center. The methods used for the study was a ‘Completely Randomized Design’ (CRD) with four treatments. The salinity used is 15, 25, 35 and 45 ppt. The main parameters observed were growth and lipid content, while the supporting parameters were temperature, and pH. The results of this study showed that the highest lipid content was a salinity treatment of 35 ppt with a value of 25.37% of total dry weight obtained at the end of the culture. Based on growth, the highest density occurred in 25 ppt salinity with a maximum density of 3.80 ± 0.49 x 106 cells. ml-1 and maximum growth rate of 0.36 ± 0.008 div. day-1

Effects of salinity on sexual maturity and reproduction of Poecilia velifera

Poecilia velifera is a popular fish in freshwater aquarism that naturally inhabits aquatic habitats with a wide range of salinities. Nonetheless, the effects of different salinities on the reproductive success and sex ratio of the species remain unknown. Male sex characters, sex ratio and reproductive success of P. velifera were evaluated by maintaining 160 juveniles (0.078 ± 0.011 g) in four different salinities (0; 12; 24; 36 g/L), with four replicates. The only modification observed in males was the formation of a copulatory organ from the anal fin, which was used to distinguish them from females. Timing of the formation of the male copulatory organ, and the weight and total length of males when it occurred, were recorded. Twenty-eight fish from each treatment were euthanized after 150 day to examine the gonads and confirm sex. Eight females and four males from each treatment were then kept in their respective salinity treatments for 65 days to examine the effects of salinity on reproduction. Males were kept with females in the different treatments for 15 days, at which point they were removed. Salinity was negatively correlated with male weight and length. Salinity also affected the sex ratio, with the percentages of males and females being 32.5 and 67.5%, and 27.5 and 72.5% in the salinities of 24 and 36 g of salt/L, respectively. Fifty percent of the females kept in freshwater reproduced, while there was no reproduction in the other treatments. The maintenance of P. velifera in freshwater promoted greater reproductive success and precocity, as well as larger males.

Physiological role of thiamine and weed control treatments on faba bean and associated weeds grown under salt affected soil

Background and objectiveSalinity stress is an important abiotic stress that affect adversely on crop production, so using of natural compounds to improve plant tolerance to stress is very important.Materials and methodsTwo field experiments were conducted during two winter seasons of 2014/2015 and 2015/2016 at Tag El-Ezz Research Station of Agricultural Research Centre, Dakahliea Egypt. Field evaluation of the efficiency of weed-control treatments (unweeded, oxadiargyl, and two hand hoeing) and thiamine levels (0, 50, 75, and 100 mg/l) and their interactive effects on weeds, faba bean growth, yield, yield attributes, and some biochemical constitutes of seeds under salinity levels (1.37, 3.31, and 4.51 dS m−1).ResultsData revealed that number and dry weight of broad-leaved, narrow-leaved, and total weeds were significantly reduced by increasing salinity levels of soil from 1.37 to 4.51 dS m−1. In addition, the highest salinity level 4.51 dS m−1 caused the highest significant decreases in growth, yield, and yield attributes of faba bean. Meanwhile, increasing salinity level from 1.3 to 4.51 dS m−1caused significant increases in total soluble sugar, free amino acids, and proline contents of faba bean plant. Two hand hoeing treatment achieved the highest weed depression expressed in the lowest dry matter of total weeds. Also, two hand hoeing was the most effective weed control treatment in increasing growth, yield, yield attributes, and some biochemical constitutes of faba bean seeds followed by of oxadiargyl treatment. No significant differences between application of two hand-hoeing and oxadiargyl treatment on all studied parameters. Foliar treatment of faba bean plants with thiamine different concentrations could alleviate the harmful effects of different salinity levels.ConclusionWe could conclude that foliar application of thiamine at the rate of 100 mg/l caused the highest increases in all growth and yield parameters under investigation of faba bean plant. Interaction of 100 mg/l thiamine treatment and two hand hoeing was the most effective treatments on enhancing faba bean growth, yield, and its attributes under salinity levels. Results also indicated that free amino and proline works to increase faba bean plants ability to withstand salinity stress.

Salinity can change the lipid composition of adult Chinese mitten crab after long-term salinity adaptation.

The Chinese mitten crab (Eriocheir sinensis) is an euryhaline crustacean, whose adults migrate downstream to estuaries for reproduction. Lipids are believed to be involved in salinity adaptation during migration. This study investigated the effects of different salinities (0, 6, 12, and 18‰) on the total lipids, neutral lipids, and polar lipids contents, and fatty acid profiles in the gonads, hepatopancreas, and muscles of adult E. sinensis after 40 days of salinity adaptation. The results showed that the males and females from 12‰ treatment had the highest contents of total lipids and neutral lipids in their hepatopancreas and total lipids in the muscles. Notably, salinity had a greater effect on the fatty acid profiles in the hepatopancreas compared to that in the gonads and muscles. The male hepatopancreas treated with 18‰ salinity had the highest percentage of total n-6 polyunsaturated fatty acid (∑n-6PUFA) in both neutral lipids and polar lipids, while the percentage of total n-3 polyunsaturated fatty acid (∑n-3PUFA) in neutral lipids and polar lipids decreased significantly with increasing salinity in males. In females, the 0‰ treatment had the highest percentages of total saturated fatty acids in neutral lipids and polar lipids in the hepatopancreas, while the highest ∑n-3PUFA and ∑n-6PUFA in neutral lipids and polar lipids were detected in the 12‰ treatment group. In conclusion, brackish water could promote the accumulations of total lipids and neutral lipids in the hepatopancreas and change the fatty acid profiles of adult E. sinensis, particularly in the hepatopancreas after long-term salinity adaptation.