Salinity Groups Research Articles

Effects of Low Salinity on Growth, Survival, and Stress Response in the Longtooth Grouper, Epinephelus bruneus, and E. bruneus × E. lanceolatus Hybrid Grouper

This study investigated the effects of low salinity on growth, survival, and stress response in longtooth grouper, Epinephelus bruneus, and the hybrid grouper resulting from crossing E. bruneus females and E. lanceolatus males. There were no significant differences in the hybrids for any of the above growth values among different salinity groups, however the percent weight gain was significantly lower in the 8 Practical Salinity Unit (psu) group than in the other salinity groups. As for survival, only longtooth grouper in the group reared at 8 psu died. The plasma cortisol levels tended to increase at lower salinities in both the longtooth grouper and the hybrids. Plasma Na+, K+, Cl– concentrations in the hybrid were not significantly different among the salinity groups, while Na+ and Cl– concentrations in the longtooth grouper were significantly lower in the 8 psu group than in the other treatments. The above results indicate that both the longtooth grouper and the hybrid grouper juveniles were highly adaptable to variations in salinity. The optimal salinity for rearing longtooth grouper was found to be 24 psu, while the hybrids had a larger tolerance range of 16-32 psu. Results therefore showed that the hybrid grouper has a higher tolerance than the longtooth grouper for low salinity.

Screening the differentially expressed proteins by protein chip in gill of red tilapia ( Oreochromis mossambicus♀ × O. niloticus♂ ) under salinity stress

PDF HTML阅读 XML下载 导出引用 引用提醒 利用蛋白抗体芯片筛选盐胁迫下红罗非鱼鳃差异表达蛋白 DOI: 作者: 作者单位: 农业部淡水水产种质资源重点实验室, 上海海洋大学, 上海 201306 作者简介: 黄思颖(1993-),女,硕士研究生,从事动物遗传育种与繁殖研究.E-mail:380006565@qq.com 通讯作者: 中图分类号: S917 基金项目: 国家现代农业产业技术体系建设专项（CARS-46）；水产动物遗传育种中心上海市协同创新中心（ZF1206）. Screening the differentially expressed proteins by protein chip in gill of red tilapia (Oreochromis mossambicus♀×O. niloticus♂) under salinity stress Author: Affiliation: Key Laboratory of Freshwater Fisheries Germplasm Resource, Ministry of Agriculture;Shanghai Ocean University, Shanghai 201306, China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为从蛋白角度探索红罗非鱼（）在盐胁迫环境下的调节适应机制，本研究采用蛋白抗体芯片结合串联质谱技术初步筛选了盐胁迫下红罗非鱼鳃组织的差异表达蛋白，并通过免疫组化和免疫印迹技术对候选差异蛋白进行了验证。结果显示，共筛选获得181个表达量有显著差异的蛋白质（变化倍数≥ 1.5），包含上调蛋白142个，下调蛋白39个。挑选5个蛋白进行质谱鉴定得到3个蛋白质：中间丝蛋白（intermediate filament protein，IF）、转运蛋白63（translocation protein 63，SEC63）、蛋白质二硫键异构酶A3（protein disulfide-isomerase A3，PDIA3）。免疫组化结果显示，在淡水、盐度组中，IF和PDIA3在鳃小片基部均有阳性反应，且随盐度升高，阳性反应呈先降低后增强的趋势，SEC63无阳性反应。Western blot结果显示，在淡水和盐度组中，IF和PDIA3两种蛋白均有表达，并且随盐度升高呈现先降低、再升高的变化趋势，SEC63蛋白无明显目的条带；在30盐度组中，胁迫早期，IF蛋白表达量降低，48 h达到最低值，72 h有明显回升，PDIA3蛋白表达量在胁迫后96 h显著升高（<0.05）。根据研究结果推测，IF和PDIA3是在盐胁迫环境下红罗非鱼鳃组织的响应蛋白，它们分别在细胞骨架、内质网功能维持中发挥重要调节作用。 Abstract:Due to its rapid growth rate and excellent adaptability to saline environments, the red tilapia () could be a suitable subject for studies on saline tolerance. In this study, to provide a theoretical basis for saline tolerance mechanisms, we aimed to screen and identify differentially expressed proteins in the gill of Red tilapia using protein chips and mass spectrometry, which were subsequently verified by using immunohistochemistry and western blot techniques. There were 181 differentially expressed protein spots detected (change multiple ≥ 1.5), which included 142 up-regulated proteins and 39 down-regulated proteins. Among these, three proteins were identified by mass spectrometry from five differentially expressed proteins:intermediate filament protein (IF), translocation protein 63 (SEC63), and disulfide-isomerase A3 (PDIA3). The immunohistochemistry results showed that IF and PDIA3 are expressed in the gill base of red tilapia under both freshwater and saline water conditions, and showed a trend of initial decrease and then increase with an increase of saline concentration. However, no positive reaction was detected for SEC63. The western blot results showed IF and PDIA3 expression level changes in different saline waters similar to those observed using immunohistochemistry. In the 30 g/L salinity group, the expression of IF protein decreased during the early stage of stress, reached the lowest value at 48 h, and thereafter began to rise significantly at 72 h, The expression of PDIA3 protein was significantly increased after 96 h ( < 0.05). These results suggest that IF and PDIA3 are positively responsive proteins in the gill tissues of red tilapia under salinity stress, and play important roles in the regulation of cytoskeleton and endoplasmic reticulum function. 参考文献 相似文献 引证文献

Effect of temperature and salinity on mtDNA copy number of the ridgetail white prawn, Palaemon carinicauda Holthuis, 1950 (Decapoda, Palaemonidae)

Abstract To explore the effect of temperature and salinity on the mitochondrial DNA (mtDNA) copy number of Palaemon carinicauda Holthuis, 1950, 5 temperature groups (10, 15, 20, 25 and 30°C) and 6 salinity groups (10, 15, 20, 25, 30 and 35) were set up, respectively. Subsequently, the numbers of copies of mtDNA of samples from all groups were detected by the TaqMan probe method. The results showed that the mtDNA copy number in the temperature samples was 2388, 2366, 4158, 4805 and 6027 at the above-mentioned temperature values, respectively. Obviously, the number of mtDNA copies in the cell tends to increase as temperatures rise. In addition, the mtDNA copy numbers of the salinity samples was 2609, 2593, 3215, 3478, 2618 and 2709, respectively, at the experimental salinities as listed above. This indicates, that the copy numbers of mtDNA tend to increase at first, and then again to decrease as the salinity values rise and pass beyond a threshold.

Effects of specific wavelength spectra on antioxidant stress and cell damage of the ornamental cleaner shrimp Lysmata amboinensis (De Man, 1888) (Decapoda, Caridea, Lysmatidae) exposed to changing saline environments

AbstractA variety of environmental factors have a major influence on the survival of aquatic organisms, particularly light and salinity, changes in which lead to a range of physiological changes. In the present study, we investigated the levels of stress caused by changes in salinity in the ornamental cleaner shrimp,Lysmata amboinensis, as well as the effect of specific light wavelengths following stress to changes in salinity. We measured the activity of superoxide dismutase (SOD), catalase (CAT), and lipid peroxidation (LPO) in the tissues (gill, hepatopancreas, and muscle) for three days after irradiating shrimp with specific wavelengths of light [red (630 nm), green (520 nm), and blue (455 nm)] at two intensities (0.5 and 1.0 W/m2) following exposure to different saline environments [25 practical salinity units (psu), 30 psu, 35 psu (normal seawater), and 40 psu]. DNA damage was measured using comet assays. Although all of the experimental groups exhibited negative results to changes in salinity, the green and red light groups exhibited positive effects when compared to the other wavelengths and fluorescent light. The effect of wavelength was not influenced by the intensity. In conclusion, the light of green and red wavelengths effectively reduces antioxidant stress and cell damage in cleaner shrimp.

Expression of genes related to antioxidant activity in Nile tilapia kept under salinity stress and fed diets containing different levels of vitamin C

ABSTRACTThe aim of this study was to examine whether (1) severe changes in salinity produced increased stress, and (2) vitamin C supplementation might reduce the observed damage in Nile tilapia. The parameters measured included condition factor, survival rate, and gene expression of catalase (CAT), heat shock protein 70 (HSP70), glutathione reductase (GSR), glutathione synthase (GSS), and glutathione peroxidase (GPx). The investigation was conducted with 160 Nile tilapia divided into four treatment groups: freshwater; 7 or 21 parts per thousand (‰) salinity, all fed a basal diet; as well as a fourth treatment group consisting of fish kept at 21‰ salinity fed a diet supplemented with vitamin C (1500 mg/kg). For gene expression analysis, liver samples were collected after 24 h or after 14 d. After 24 h, fish raised in 21‰ salinity and fed with the diet supplemented with vitamin C showed similar GPx expression as the control freshwater group. GSS expression in 21‰ salinity was similar to fish exposed to 7‰ salinity. Nile tilapia exposed to 21‰ salinity without vitamin C supplementation exhibited the highest HSP70 gene expression levels after 24 h. After 14-dtreatment, the lowest survival rate was observed in the 21‰ salinity group. After 14 d, the highest expression of GPx and GSR levels was detected in fish in the 21‰ salinity group that received vitamin C. Data indicate that vitamin C supplementation enhanced the expression of genes related to antioxidant capacity in Nile tilapia exposed to higher salinity, thereby increasing protection against the oxidative effects induced by high water salinity.</AB>

A GC-MS based metabolomics approach to determine the effect of salinity on Kimchi

GC-MS datasets coupled with multivariate statistical analysis were used to investigate metabolic changes in Kimchi during fermentation and metabolic differences in Kimchi added with various amounts (0, 1.25, 2.5, and 5%) of salts. PCA score plot obtained after 1day of fermentation were clearly distinguishable by different salinity groups, implying that early fermentation speed varied according to Kimchi salinity. PLS-DA score plot from data obtained on the 50th day of fermentation also showed a clear separation, indicating metabolites of Kimchi were different according to salinity. Concentrations of lactic acid, acetic acid, and xylitol were the highest in Kimchi with 5% salinity while concentration of fumaric acid was the highest in Kimchi with 0% salinity. Rarefaction curves showed that numbers of operational taxonomic units (OTUs) in Kimchi with 5% salinity were higher than those in Kimchi with 0% salinity, implying that Kimchi with 5% salinity had more bacterial diversities. This study highlights the applicability of GC–MS based metabolomics for evaluating fermentative characteristics of Kimchi with different salinities.

The salinity tolerance of the invasive golden apple snail (Pomacea canaliculata)

ABSTRACTWe exposed snails of an invasive species of golden apple snail (Pomacea canaliculata) to five artificial sea water treatments at salinity levels of 0, 5, 10, 15 or 20 parts per thousand (ppt) to assess their salinity tolerance. We observed the behaviour, heart rate, total haemocyte counts, haemolymph ionic concentration and Na+/K+-ATPase activity in the mantle at 0, 12, 24, 48, 72 and 96 h post salinity exposures. The heart rate declined with increasing salinity, while Na+/K+-ATPase activity in the mantle presented a reverse trend, possibly to maintain normal osmolality. A trend of rising total haemocyte count was observed from 0 ppt and 5 ppt to 10 ppt salinities, while a sudden increase in the count was observed at 15 ppt and 20 ppt salinity groups. Furthermore, haemolymph Cl−, Na+ and K+ concentrations increased directly with elevated salinity. An additional trial was performed to assess the growth performance of the snails under exposure to low salinities. During a 1 month trial, snails grew better at 5 ppt salinity treatment. Taken together, our results demonstrate that P. canaliculata can tolerate salt stress to some extent. The finding also obviously implies a possible invasive risk to estuaries.

Salinity Alters the Polyisoprenoid Alcohol Content and Composition of Both Salt-Secreting and Non–Salt-Secreting Mangrove Seedlings

The effects of salinity on the polyisoprenoid alcohol content and composition of the salt-secreting mangrove species Avicennia marina and Sonneratia alba and the non–salt-secreting species Bruguiera gymnorrhiza and Kandelia obovata were studied. The seedlings of mangroves were grown for 5 months under 0% and 3% salt concentrations. The occurrence, content, and distribution of four mangrove seedlings were analyzed by two-dimensional thin layer chromatography. The structural groups of the polyprenols and dolichols in the leaves and roots were classified into two types (I and II). In type I, dolichols predominated over polyprenols (more than 90%), whereas in type II, the occurrence of both polyprenols and dolichols was observed. Polyprenols were not detected in the leaves of A. marina and B. gymnorrhiza under 0% salt (control), but were detected in small amounts in K. obovata leaves; however, significant amounts were found in the 3% salinity group. This finding in A. marina, B. gymnorrhiza, and K. obovata leaves implies a change to the structural group: under 0% salt concentrations, the groups are classified as type I, but become type II under 3% salt concentrations. The occurrence of ficaprenol (C50–55) was found only in the leaves of the non–salt-secreting species B. gymnorrhiza and K. obovata under 3% salinity and not in the salt-secreting species A. marina or S. alba. It is noteworthy that the polyisoprenoid type in the roots of the four species showed no change under salinity; the two salt-secreting species A. marina and S. alba contained type I under 0% and 3% salt concentrations. On the other hand, type II polyisoprenoids were identified in the non–salt-secreting species B. gymnorrhiza and K. obovata under 0% and 3% salinity conditions. This finding suggested that polyisoprenoids play a protective role against salinity in the mangrove leaves of both salt-secreting and non–salt-secreting species.

Optimal salinity for rearing Chinese black sleeper (Bostrychus sinensis) fry

The Chinese black sleeper (Bostrychus sinensis) is a commercially important fish in southeastern China, but the effects of salinity on the growth of B. sinensis fry remain unclear. In the present study, the three month-old B. sinensis fry were reared for 5weeks at 5, 15, 25 and 35 parts per thousand (ppt) salinities to evaluate the effects of salinity on the survival rate, specific growth rate, condition factor, feed intake (FI), food conversion efficiency (FCE), plasma osmolality, plasma Cl− concentration and the gill Na+-K+-ATPase (NAK) activities. In addition, since the insulin-like growth factor (IGF) system plays important roles in osmoregulation and promoting growth in teleosts, the complete B. sinensis insulin-like growth factor-1 receptor (igf-1r) gene was cloned and igf-1r mRNA levels in the muscle and gill were measured at the end of this experiment. Our results showed that the fry reared at lower salinities (5 and 15 ppt) grew significantly faster than those at higher salinities (25 and 35 ppt), and the fry reared at 15 ppt exhibited lower FI and higher FCE than those reared at 5 ppt. A typical ‘U-shaped’ pattern of gill NAK activity levels with the lowest one at 15 ppt was observed, suggesting that a lower energy expenditure on osmoregulation at this level of salinity. The length of the complete igf-1r cDNA sequence was 6864bp, and it had a wide range of tissue expression including muscle and gill. After 5weeks of rearing, muscle igf-1r mRNA levels were similar among the four salinity groups, while the gill igf-1r mRNA level at 5 ppt was significantly higher than that at 15 ppt. Taken together, the results from the present study indicated that the optimal salinity for rearing B. sinensis fry was 15 ppt, and that IGF-1 might serve as a hyperosmoregulatory hormone in long-term low salinity acclimation in B. sinensis.

COMPARING LIVING AND HOLOCENE COCCOLITHOPHORE ASSEMBLAGES IN THE AEGEAN MARINE ENVIRONMENTS

Detailed quantitative analyses of coccolithophores performed on the shallow deposits of the southeastern Aegean region (core NS-14, 505 m depth), evidenced that the distribution of calcare-ous nannoplankton assemblages during the last 13 ka BP reflects paleoenvironmental changes which are directly related to parameters such as temperature, salinity, productivity and nutrient flux in the water column. Analysis enabled the separation of the assemblages in four groups. Group A consists of Emiliania huxleyi and the subtropical species Syracosphaera spp. and Rhabdosphaera clavigera, Group B is composed of Helicospaera spp. and Florisphaera profunda, typical species for high productivity conditions in the middle-lower photic zone, Group C consists of Gephyrocapsa oceanica and Braarudosphaera bigelowii, that characterise low salinity conditions and Group D includes Umbilicosphaera spp. and Calcidiscus spp. which are described as relatively eutrophic species. The Holocene assemblages differ distinctly from the living coccolithophore communities in the coastal ecosystems of the Aegean Sea, where only Group A coccolithophores are thriving in the seasonally controlled marine environment.

Effects of different salinities on growth performance, survival, digestive enzyme activity, immune response, and muscle fatty acid composition in juvenile American shad (Alosa sapidissima)

The effects of salinity on survival, growth, special activity of digestive enzymes, nonspecific immune response, and muscle fatty acid composition were evaluated in the American shad (Alosa sapidissima). Juveniles of 35days after hatching were reared at 0 (control), 7, 14, 21, and 28ppt for 60days. At the end of the experiment, juvenile American shad presented higher survival and specific growth rate (SGR) in salinity group (7, 14, and 21ppt) than control group (P<0.05). The special activity of trypsin and chymotrypsin was highest in fish reared at 21ppt, while the highest lipase special activity was obtained in control group (P<0.05). The special activity of alkaline phosphatase (ALP), lysozyme (LZM), superoxide dismutase (SOD), and catalase (CAT) showed significant increases in salinity group (14 and 21ppt) compared to control group (P<0.05). Lower muscle ash contents were detected in salinity group (14, 21, and 28ppt) than control group (P<0.05), while the contents of crude lipid and crude protein were significantly higher than control group (P<0.05). The level of monounsaturated fatty acids (MUFA) exhibited a decreasing trend, while an increased level of polyunsaturated fatty acids (PUFA) was detected with the increase of salinity. Among the PUFA, the content of n-3 fatty acids in muscle tissue was found to be increasing with the increasing salinity, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Results indicate that appropriate increase in salinity was reasonable and beneficial for juvenile American shad culture after a comprehensive consideration, especially salinity range from 14 to 21ppt.

Effects of salinity on cold tolerance of Malaysian red tilapia

This study was conducted to investigate the effect of salinity on growth, survival, osmoregulation, metabolism, hematological and biochemical parameters and T-complex protein (TCP-1) mRNA expression levels in Malaysian red tilapia at declining tank water temperatures. Five salinity concentrations (0, 5, 10, 15, 20 ‰) were evaluated during the study period. Samples were collected on a range of biochemical parameters at 16.5 (week 2), 12 (week 4) and 9.5 °C (week 6). No significant growth (body weight) was showed in the study (P > 0.05). Survival was monitored in the groups of fish until the holding tank temperature reached 5.6 °C. The lowest temperature in the study population of Malaysian red tilapia tolerated was 9 °C, although the fish were able to survive in temperature of 5.6 °C if they had been reared at 10 ‰ water salinity. The salinity and change in water temperature had significant effects on hematological and biochemical parameters and the TCP-1 gene expressions in Malaysian red tilapia (P < 0.05). The effect of temperature and salinity on superoxide dismutase (SOD), malondialdehyde (MDA) and hemoglobin (HGB) levels was significant (P < 0.05 or P < 0.01); with decreasing temperature, SOD and MDA activities increased, whereas HGB concentrations decreased. With increasing level of salinity, the SOD, MDA and blood glucose levels significantly increased (P < 0.05). The highest cholesterol (TC), triglycerides (TG), red blood cells (RBC) and HGB values were apparent in the moderate salinity groups, whereas the highest high-density lipoprotein cholesterol (HDL-C) was in the moderately high-salinity group. Rearing at low temperature, Na+–K+-ATPase (NKA) increased with increasing level of salinity at 16.5 °C, although it initially declined before rising again at water temperatures 12 and 9.5 °C. Rearing at low temperature, fish in the low-salinity groups significantly up-regulated the expression of the TCP-1 genes (P < 0.05), whereas fish in mild to moderate salinity groups significantly down-regulated the expression (P < 0.05). Taken together, these results suggest that exposure to environmental conditions of low temperature, low salinity and high salinity influence osmoregulation, metabolic parameters and the fish physiology. However, a change in the isotonic point at cold temperatures was observed by rearing in a salinity of under 10 ‰. This could potentially provide a means to increase cold tolerance of overwintering Malaysian red tilapia.

Molecular performance of Prl and Gh/Igf1 axis in the Mediterranean meager, Argyrosomus regius, acclimated to different rearing salinities.

Aquaculture industry in the Mediterranean region exhibits a growing interest for the Mediterranean meager Argyrosomus regius. Some preliminary works showed a good growth performance of the species in nearly isosmotic salinities. However, the patterns of alteration of prolactin (Prl) as well as growth hormone (Gh)/insulin growth factor-1 (Igf1) axis at the molecular level are not yet described in this species. Therefore, we cloned and sequenced partial cDNAs for pituitary prolactin (prl) and growth hormone (gh), hepatic insulin-like growth factor (igf1), and β-actin (actb). Expression patterns of these transcripts were tested in juveniles of A. regius acclimated to four different environmental salinities: (1) 5‰ (hyposmotic); (2) 12‰ (isosmotic); (3) 38‰ (hyperosmotic; seawater control); and (4) 55‰ (extremely hyperosmotic). All investigated transcripts shared high sequence identities with their counterparts in other perciformes. prl mRNA levels showed inverse pattern with increasing salinities. gh mRNA enhanced significantly in both 12 and 55‰ salinity groups in comparison with the control group, while igf1 showed its maximum expression levels under the nearly isosmotic environment. The results indicated clear sensitivity of prl, gh and igf1 to changes in environmental salinity, which can possibly control the euryhalinity capacity of this species.

Antigen uptake and expression of antigen presentation-related immune genes in flounder (Paralichthys olivaceus) after vaccination with an inactivated Edwardsiella tarda immersion vaccine, following hyperosmotic treatment.

Antigen uptake is a critical process for activation of the immune system, and therefore the ability to enhance antigen uptake is a primary consideration in the development of an immersion vaccination of fish. In the present work, flounders (Paralichthys olivaceus) were immersed in three hyperosmotic solutions with 40, 50 and 60‰ salinities, then transferred into seawater of normal salinity (i.e. 30‰) containing formalin-inactivated Edwardsiella tarda for 30min. The antigen uptake in vaccinated flounder was determined using an absolute quantitative PCR (qPCR). The results showed significantly higher antigen uptake in the tissues of flounders immersed in solutions with 50‰ and 60‰ salinity compared to the control group directly immersed in vaccine (DI) (P<0.05), and the highest amount of antigen was detected in flounders immersed in the 50‰ salinity solution, whereas there was no significant difference in antigen uptake between the 40‰ salinity group and the DI group (P>0.05). A rapid and significant increase in antigen uptake was detected in the mucosal-associated tissues including the gill, skin and intestine (P<0.05) compared with the spleen, kidney and liver. Antigen uptake in the gill and skin both peaked at 30min post immersion, which was significantly higher than the levels of uptake measured in the other tissues (P<0.05), and then quickly declined. In contrast, antigen uptake in the spleen, kidney and liver gradually increased 3h post immersion (hpi). The expression profiles of four antigen presentation-related immune genes (MHC Iα, MHC IIα, CD4-1 and CD8α) were investigated after immersion. These four genes showed a significantly stronger response in the immersed flounders exposed to 50‰ salinity compared with the DI group (P<0.05). In the mucosal-associated tissues, the expression of MHC Iα and CD8α genes peaked at 24 hpi, while the expression of MHC IIα and CD4-1 genes showed up-regulation in the gill and skin and reached the peak in these tissues at 48 hpi. The expressions of the four genes were also up-regulated in spleen, kidney and liver, but reached peak expression in these tissues at 48-72 hpi. The results demonstrated that hyperosmotic immersion, notably 50‰ salinity significantly enhanced antigen uptake and the expression of selected genes associated with antigen presentation, providing evidence for an enhanced immune activation of the fish's immune response by the hyperosmotic immersion treatment prior to vaccination.

Multivariate statistical analysis of the groundwater of Ain Djacer area (Eastern of Algeria)

The intensive exploitation of groundwater resources in the region of Ain Djacer has greatly influenced the hydrochemical functioning of the superficial aquifer. This has resulted in a general decline of the piezometric level of the groundwater, a mineralization of water and calcium facies near limestone and sodium chloride in the center of the plain in liaison with the lithology. To highlight the hydrochemical processes of groundwater, a study by major ions were analyzed in 21 groundwater samples collected from this aquifer during the month of March 2004. Multivariate statistical techniques and cluster and principal component analysis were applied to the data on groundwater quality, with the objective of defining the main controls on the hydrochemistry at the plain. These statistical techniques have shown the presence of three salinity groups with increasing importance according to the direction of flow. The initial facies on the limits as well as infiltration areas is bicarbonate. In the center of the plain, water becomes charged with sodium (Na) and chlorine (Cl) in connection with the dissolution of salt formations. The presence of nitrates is related to agricultural activity.

Effect of salinity on regulation mechanism of neuroendocrine-immunoregulatory network in Litopenaeus vannamei.

The effects of low salinity (transferred from 31‰ to 26‰, 21‰, and 16‰) on the regulation pathways of neuroendocrine-immunoregulatory network were investigated in Litopenaeus vannamei. The results showed that the hormones (corticotrophin-releasing hormone, adrenocorticotropic hormone) and biogenic amines (dopamine, noradrenaline, 5-hydroxytryptamine) concentrations in lower salinity groups increased significantly within 12h. The gene expression of biogenic amine receptors showed that dopamine receptor D4 and α2 adrenergic receptor in lower salinity groups decreased significantly within 12h, whereas the 5-HT7 receptor significantly increased within 1d. The second messenger synthetases (adenylyl cyclase, phospholipase C) and the second messengers (cyclic adenosine monophosphate, cyclic guanosine monophosphate) of lower salinity groups shared a similar trend in which adenylyl cyclase and cyclic adenosine monophosphate reached the maximum at 12h, whereas phospholipase C and cyclic guanosine monophosphate reached the minimum. The immune parameters (total hemocyte count, phenoloxidase activity, phagocytic activity, crustin expression, antibacterial activity, C-type lectin expression, hemagglutinating activity) in lower salinity groups decreased significantly within 12h. Except for the total hemocyte count, all the parameters recovered to the control levels afterwards. Therefore, it may be concluded that the neuroendocrine-immunoregulatory network plays a principal role in adapting to salinity changes as the main center for sensing the stress and causes immune response in L.vannamei.

Geological, geochemical, and fluid inclusion evidences for the origin of the Ravanj Pb–Ba–Ag deposit, north of Delijan city, Markazi Province, Iran

The Lower Cretaceous sequences of the Ravanj anticline in Iran host the Ravanj Pb-Ba-Ag mineralization. Economic orebodies are restricted to the thrust zone within the brecciated massive limestone and immediately above the Jurassic shale and/or shale-limestone intercalations of the Lower Cretaceous. Paragenetic sequence and distinct zoning of mineral assemblages indicate that ore-forming fluid migrated through thrust zones along the NE-trending faults. The REE pattern of mineralized host rock is characterized by HREE-enrichment ((La/Lu)PAAS = 0.24). The Ce/Ce* ratio of mineralized host samples shows negative Ce anomalies, which is most likely inherited from seawater. The positive Eu/Eu* anomaly suggests high ?O2 during ore deposition. Negative Δ34S values of the Ravanj sulfide minerals (-27? to -11?) suggest bacteriogenic sulfate reduction, whereas positive Δ34S values of barite (+20?) fall in the range of Tertiary marine sulfates. Multiple isotopic sulfur sources of sulfides and sulfate minerals support mixing of a reduced negative isotopic sulfur-bearing fluid and a positive isotopic sulfate-bearing fluid. The average of homogenization temperatures of fluid inclusions from the early and late-stage mineralization calcites are 165 and 160 °C, respectively. The salinity of fluid inclusions varies between 0.66 and 18 wt% NaCl equivalent with an outlier at 22.2. Wide variation in the salinity of fluid inclusions can be explained by fluid mixing between a higher salinity group with 14-18 wt% NaCl equivalent and a lower salinity group with 0.66-8 wt% NaCl equivalent. In the Ravanj, fine grained sulfide minerals are consistent with a sulfur supersaturated fluid. High concentrations of Pb can be present in oxidized, chlorine-bearing fluids if the concentration of total H2S is very low. Therefore, mixing of two geochemically different fluids could precipitate both galena and barite. These data show that the Ravanj Pb-Ba-Ag deposit is comparable with Pb-rich Mississippi Valley-type deposits such as the Viburnum Trend district in the USA.

Nesting population structure of larks (Alaudidae, Aves) in typical semidesert habitats of the Caspian Lowland

The distribution of nesting populations of individual lark species by semidesert habitats in the Caspian Lowland is analyzed on the basis of data on the density of nesting pairs estimated by transect counts. The counts have been taken in 25-km2 key areas, in combination with mapping and description of soils and vegetation. Such an integrated approach has made it possible to reveal habitat preferences of individual Alaudidae species characteristic of the northwestern Transvolga part of the Caspian Lowland. It is shown that the distribution of lark species in a monotonous plain depends primarily on its meso-and microrelief as the main factor determining the patterns of soil salinity and vegetation groups, which, in turn, determine specific features of bird habitats.

Immune responses of flounder Paralichthys olivaceus vaccinated by immersion of formalin-inactivated Edwardsiella tarda following hyperosmotic treatment.

The aim of the present study was to evaluate the effects of hyperosmotic immersion (HI) vaccination and determine the optimum hyperosmotic salinity for flounder Paralichthys olivaceus by investigating its immune responses following vaccination. Flounder were immersed in 1 of 3 hyperosmotic solutions at 50, 60 and 70‰ salinity, then transferred into 30‰ salinity normal seawater containing formalin-inactivated Edwardsiella tarda for vaccination (3 HI groups), or were immersed in normal seawater as direct immersion (DI group). The results showed that the percentages of surface membrane immunoglobulin-positive (sIg+) cells in peripheral blood leukocytes and spleen leukocytes induced by HI were significantly higher than that with DI (p < 0.05), and the 50‰ salinity group showed the strongest response among the HI groups, which reached peaks at Week 4. ELISA assay showed that the specific serum antibodies gradually increased after vaccination and reached peak at Day 32, and the fish treated with HI showed stronger antibody responses; among the HI groups, a significantly higher specific antibody level was detected in the 50‰ salinity group at Day 32 (p < 0.05). Similarly, the fish treated with HI showed higher specific mucosal antibody levels compared to the DI group, and the mucosal antibody showed a faster response, with peak time arriving 1 wk earlier than for the serum antibody. The relative percent survival (RPS) of flounder treated with HI at 50, 60 and 70‰ salinities were 79, 71 and 57% respectively, while this was 43% in the DI group. These results demonstrated that HI, especially the 50‰ salinity, could efficiently enhance the immune response of flounder and show higher RPS. This has significant value for immunological prevention of edwardsiellosis in flounder.

Growth and Lipid Metabolism of the Pacific White ShrimpLitopenaeus vannameiat Different Salinities

Juvenile white shrimp Litopenaeus vannamei (1.98 ± 0.28 g) were fed a commercial diet for 8 wk in triplicate to investigate growth and lipid metabolism at 3 salinities (3, 17, and 30). Shrimp weight gain and survival at 3 were significantly less than that at 17 and 30. No differences were found in whole-body proximate composition. Linolenic acid (18:3[n-3]) and (n-3) long-chain unsaturated fatty acid levels in the hepatopancreas, and n-3 long-chain polyunsaturated fatty acid level, especially eicosapentaenoic acid (EPA; C20:5[n-3]) and docosahexaenoic acid (DHA; C22:6[n-3]) in muscle at 3 were significantly greater than at other salinities. Fatty acid synthase, hormone sensitive lipase, lipoprotein lipase, adipose triacylglycerol lipase, acyl-CoA, diacylglycerol acyltransferase 2, elongase of very long-chain fatty acid 6, and Δ5 and Δ6 fatty acid desaturase activity was detected and showed a negative trend with an increase of salinity, and no significant differences were found among salinity groups (P > 0.05). The results indicate that the low salinity of 3 decreases the growth of L. vannamei. Although L. vannamei could not synthesize either DHA or EPA de novo, it possibly has the potential ability to convert linolenic acid to DHA and EPA regardless of salinity. However, the factors influencing this ability remain unknown and need further study.