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The age and growth of an Asturian population of the bib Trisopterus luscus L. were studied based on 990 bibs from monthly catches from October 1986 until October 1988.Using the estimates of age taken from otolith readings, it was possible to construct a growth curve for the whole range of ages and demonstrate that most growth takes place during the first two years of life. The maximum age was found to be 5 years. The largest fish caught during the investigation measured 430 mm in standard length.The different growth rates of males and females show that in most cases the mean standard length of females was equal to or greater than that of the males. 相似文献
3.
Kang Wang Hui Lin Conghui Peng Lin Sun Yahui Gao Baohong Chen 《Global Change Biology》2023,29(17):5099-5113
Noctiluca scintillans is one of the most common harmful algal species and widely known due to its bioluminescence. In this study, the spatial distribution, seasonal variations, and long-term trends of N. scintillans blooms in China and the related drivers were analyzed and discussed. From 1933 to 2020, a total of 265 events of N. scintillans blooms were recorded in Chinese coastal waters, with a total duration of 1052 days. The first N. scintillans bloom occurred in Zhejiang in 1933, and only three events were recorded before 1980. From 1981 to 2020, N. scintillans caused harmful algal blooms (HABs) almost every year, both the average duration and the proportion of multiphase HABs showed an increasing trend. 1986–1992, 2002–2004, and 2009–2016 were the three peak periods with a frequency of no less than five events of N. scintillans blooms per year. In terms of spatial distribution, N. scintillans blooms spread from the Southeast China Sea to the Bohai Sea after 2000, Guangdong, Fujian, and Hebei were the three provinces with the highest numbers of recorded events of N. scintillans blooms. Moreover, 86.8% of the events of N. scintillans blooms occurred in spring (March, April, and May) and summer (June, July, and August). Among environmental factors, the dissolved inorganic phosphate, dissolved silicate and chemical oxygen demand were significantly correlated with the cell density of N. scintillans during N. scintillans blooms, and most of N. scintillans blooms were recorded in the temperature range of 18.0–25.0°C. Precipitation, hydrodynamics, water temperature, and food availability might be the main factors affecting the spatial–temporal distribution of N. scintillans blooms along the Chinese coast. 相似文献
4.
《Saudi Journal of Biological Sciences》2020,27(8):2065-2075
The marine microbiome is a complex and least-understood habitat, which play a significant role in global biogeochemical cycles. The present study reported the culture-independent assessment of microbial diversity from the Arabian Sea (AS) sediments (from Gujarat to Malabar; at 30 m depth) by using metagenome sequence analysis. Our results elucidated that bacterial communities in the Malabar coastal region are highly diverse than the Gujarat coast. Moreover, Statistical analysis (Spearman rank correlation) showed a significant correlation co-efficient value (r = P < 0.001) between microbial communities and physicochemical parameters (salinity and dissolved oxygen) in the water column. A total of 39 bacterial phyla were recorded from the eastern side of AS, of which six phyla Proteobacteria, Bacteroidetes, Actinobacteria, Cyanobacteria, Firmicutes, and Planctomycetes were found to be the most dominant group. The most dominant genus from Valapad region (Malabar Coast) was found to be Halomonas sp., while other regions were dominated with Psychrobacter pulmonis. The subsequent Principal Coordinate Analysis (PCoA) showed 99.53% variance, which suggests that, highly distinct microbial communities at Valapad (Malabar Coast) sampling location than other sites. Moreover, the microbial metabolic activity analysis revealed the important functions of microbial communities in the AS are hydrocarbon degradation, polymer degradation, nutrient oxidation and sulphate reduction (biodegradation process). Further extended studies are needed to be carried out for better understanding the functional diversity of microbial communities from the marine sediments. 相似文献
5.
R. Vijayakumar G. Gopika D. Dhanasekaran R. Saravanamuthu 《Archives Of Phytopathology And Plant Protection》2013,46(9):1010-1025
In total, 53 marine actinobacteria were isolated from the soils of six different locations in Goa and Kerala, on the west coast of India. All the isolates were screened for their antifungal properties against some phytopathogenic fungi by dual culture experiments. Among the 53 actinobacterial isolates, five isolates inhibited the growth of phytopathogens, namely Colletotrichum falcatum, Thielaviopsis paradoxa and Fusarium semitectum. But none of them were effective against Aspergillus niger, Aspergillus candidus and Aspergillus flavus. The antifungal activity of the actinobacteria was tested by food poisoning techniques, using four different concentrations (0.5%, 1.0%, 1.5% and 2.0%) of cell-free culture filtrates, which showed promising activity (almost 100% inhibition) against three pathogenic and one non-pathogenic fungi at 2% extract concentration. A comparison of the antifungal activity of the actinobacteria was also made with three commercial fungicides, namely hexaconazole, thiophanate methyl and propiconazole. The identity of the antagonistic actinobacteria was confirmed based on the morphological, cultural, biochemical, chemo-taxonomical and physiological characteristics. Among 5 antagonistic isolates, three antagonistic isolates were assigned to the genus Streptomyces, Nocardiopsis (1) and Saccharopolyspora (1). 相似文献
6.
《Chemical Speciation and Bioavailability》2013,25(4):235-246
AbstractThis article documents and interprets stratigraphical changes in fractionation of Fe, Mn, Mg, K, Pb, Cu and Zn in the Sa1/2 sediment core from a coastal freshwater lake, Lake Sarbsko (northern Poland). The elements were sequentially extracted from the samples to distinguish five geochemical fractions: exchangeable, acid-extractable, reducible, oxidisable and residual. The analyses revealed substantial variations in geochemical partitioning of the elements and showed no correlation between the fractionation patterns and lithology of the sediments. In the sediments of Lake Sarbsko, iron is mainly bound to sulfides. Potassium occurs in its residual form. Magnesium and zinc are associated with carbonates and aluminosilicates, while copper occurs in compounds with organic matter and sulfides. Lead is found in connection with aluminosilicates and, to a lesser extent, with sulfides and organic matter. Manganese is partitioned between the oxidisable, acid-extractable, and exchangeable fractions. Heavy metals and potassium display the overall tendency to reduce the contents of their residual forms towards the top of the depositional sequence. Fe, Mn, Mg and Zn were found to be the most susceptible to post-sedimentary mobilisation. 相似文献
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8.
This review updates the information upon the chemical composition of propolis from all Mediterranean countries as well as their biological properties and applications. The non‐volatile fraction of propolis was characterized by the presence of phenolic acids and their esters and flavonoids. Nevertheless, in some countries, diterpenes were also present: Sicily (Italy), Croatia, Malta, Creta (Greece), Turkey, Cyprus, Egypt, Libya, Algeria and Morocco. The volatile fraction of propolis was characterized by the presence of benzoic acid and its esters, mono‐ and sesquiterpenes, being the oxygenated sesquiterpene β‐eudesmol characteristic of poplar propolis, whereas the hydrocarbon monoterpene α‐pinene has been related with the presence of conifers. Regardless the chemical composition, there are common biological properties attributed to propolis. Owing to these attributes, propolis has been target of study for applications in diverse areas, such as food, medicine and livestock. 相似文献
9.
为揭示我国东部归化水仙(Narcissus tazetta var. chinensis)的群体遗传多样性,利用2个叶绿体基因mat K和trn H-psb A片段对采自沪、浙、闽的5个代表群体的49株水仙进行了评估。结果表明,双基因联合序列的总长为1443bp,共定义6个单倍型,各归化群体的遗传多样性水平为DLSYPTDNJD=ZZCMD。AMOVA分析表明,群体内变异为遗传变异的主要来源(91.98%),群体间的遗传分化较低(Fst=0.080 22)。群体物种水平上的谱系结构不显著(Nst=0.020Gst=0.031;P0.05)。Mantel检验表明水仙群体间的遗传距离与地理距离呈显著的线性相关(r=0.929,P=0.02 0.05)。中性检验和错配分布分析结果均暗示水仙群体背离了快速扩张模型的假设。单倍型分布的中介网络图结合系统发育NJ树均将所有群体划分为2大分支。因此,我国东部沿海水仙归化群体整体遗传多样性水平较低,各群体间遗传分化较弱,遗传变异主要来自群体内,物种近期未经历扩张事件,可能是基因流受海岛隔离、自身生物学特征、生境异质性与及人为干扰的综合作用影响。 相似文献
10.
《Saudi Journal of Biological Sciences》2022,29(8):103342
BackgroundsDiverse marine habitats along Jeddah's Red Sea coast support rich biodiversity. Few studies have been done on its diverse communities, especially its microbial counterparts. Metagenomic analysis of marine benthic micro-eukaryotic communities was performed for the first time on the Red Sea coast of Jeddah. This research looks into their community structure and metabolic potential.MethodsNext-generation sequencing was used to examine the micro-eukaryotic communities of seven sedimentary soil samples from four Jeddah coast locations. After isolating DNA from seven benthic sedimentary soil samples, the 18S rDNA V4 regions were amplified and sequenced on the Illumina MiSeq. It was also verified using an Agilent Technologies 2100 Bioanalyzer with a DNA 1000 chip (Agilent Technologies, Fisher Scientific). A standard curve of fluorescence readings generated by qPCR quantification using the Illumina library was achieved using the GS FLX library. Metagenomic data analysis was used to evaluate the microbial communities' biochemical and enzymatic allocations in studied samples.ResultsBlast analysis showed that the top ten phyla were Annelida, Eukaryota, Diatomea, Porifera, Phragmoplastophyta, Arthropoda, Dinoflagellata, Xenacoelomorpha Nematoda, and uncultured. Annelida was also found in the highest percentage (93%), in the sample M followed by Porifera (64%), the most abundant in the control sample then Eukaryotes (61%), Phragmatoplastophyta (55%), Arthropoda, and Diatomea (the least common) (32%). community diversity analysis: using Shannon and inverse Simpson indices showed sediment composition to be effective. Also, PICRUST2 indicated that the most abundant pathways were pyruvate fermentation to isobutanol, pyrimidine deoxyribonucleotide phosphorylation, adenosine ribonucleotide de novo biosynthesis, guanosine ribonucleotide de novo biosynthesis, NAD salvage pathway I, the super pathway of glyoxylate bypass and aerobic respiration I (cytochrome c).ConclusionResults showed that high throughput metagenomics could reveal species diversity and estimate gene profiles. Environmental factors appear to be more important than geographic variation in determining the structure of these microbial communities. This study provides the first report of marine benthic micro-eukaryotic communities found on the Red Sea coast of Jeddah and will serve as a good platform for future research. 相似文献