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Development and Utilization of Transcriptome SSR Markers in <em>Procambarus clarkii</em>
Full text linkTo accelerate the research process of molecular marker-assisted breeding in Procambarus clarkii, this study conducted transcriptome sequencing of P. clarkii muscle tissue using the Illumina NovaSeq platform. Microsatellites (SSRs) were analyzed for distribution and sequence characteristics using MIcroSAtellite (MISA), and genetic diversity was studied in seven cultured populations. The results showed that the sequencing yielded between 9.9 to 12.7 Gb of clean data, and after assembly, produced between 52,244 to 83,367 contigs, identifying a total of 11,304 SSR loci. The SSRs were predominantly dinucleotide and trinucleotide repeats, accounting for 33% and 27% of the total loci, respectively. The average observed heterozygosity (Ho) across the seven different regional aquaculture populations ranged from 0.374 to 0.502, while the average expected heterozygosity (He) ranged from 0.502 to 0.604. The average polymorphic information content (PIC) for the populations was greater than 0.450, indicating substantial genetic variability. According to Nei's genetic distance, an Unweighted Pair Group Method with Arithmetic Mean (UPGMA) cluster tree divided the seven different regional aquaculture populations into two major clades: one comprising Yunnan (YN) and Qianjiang (QJ) and the other comprising the remaining five populations. The study found that 93.52% of the variation originated within populations, with only 6.48% of genetic variation attributable to differences between populations. These results lay a foundation for further assessment of the genetic diversity of P. clarkii, innovative utilization of germplasm resources, and in-depth studies into its molecular genetics and evolutionary mechanisms
Research on the resilience level of fishery economy in coastal areas of China
Full text linkMultiple risks such as environmental pollution, market risk, and extreme weather pose severe challenges to fishery production, fishermen 's lives and property, and the sustainable development of fishery. Improving the resilience of fishery economy is an inevitable requirement for coping with fishery production risks and achieving high-quality development of fishery economy. Therefore, based on the three dimensions of resistance and recovery ability, adaptation and adjustment ability, innovation and transformation ability, this study constructs a comprehensive index evaluation system of fishery economic resilience, and uses entropy method and Theil index method to measure the level of fishery economic resilience and regional differences in coastal areas of China from 2016 to 2023. The conclusions are as follows: (1) From 2016 to 2023, the level of fishery economic resilience in coastal areas of China showed a fluctuating growth trend of 'first decline and then rise', with an average value of 0.2566. (2) There are significant differences in the level of fishery resilience in different coastal areas. From 2016 to 2023, Shandong Province had the highest level of fishery economic resilience (0.5226), and Hainan Province had the lowest level of fishery economic resilience (0.0751). The eastern marine economic circle has the highest fishery economic resilience (0.2713), followed by the southern marine economic circle (0.2650), and the northern marine economic circle has the lowest fishery economic resilience (0.2371). (4) The regional differences in the level of fishery economic resilience in coastal areas of China mainly come from inter-group differences, with a contribution rate of 68.36 %. The difference in the level of fishery economic resilience between the three major marine economic circles has gradually become the most important factor affecting the difference in the level of fishery economic resilience in China
A Four-Way Distance Contrast in Takbanuaz Bunun Demonstratives
No full textBunun is an Austronesian language spoken in Taiwan. Previous research on two of its dialects, Takivatan and Isbukun, indicates complex paradigms of demonstrative pronouns, locative verbs, and adverbial elements. All demonstrate two-way or three-way distance contrasts, sometimes alongside underspecified forms and a distinction in visibility. However, in the Takbanuaz dialect, a four-way distinction has been observed in certain demonstrative paradigms, which, in addition to the typical proximal-medial-distal contrast, encodes vague distance. This article describes this atypical demonstrative system and discusses how its complex distance distinction aligns with our general understanding of the properties of deixis in Austronesian languages and beyond. After providing a typological outline of demonstrative distance distinctions and a summary of research on demonstrative distance in Formosan languages in Section 2, Section 3 offers an overview of previous research on Bunun demonstratives and describes the Takbanuaz demonstrative system, with a special focus on the expression of vague and indeterminate distance. Section 4 compares distance contrasts across Bunun dialects and suggests accessibility as an explanation for the semantics of vague forms in Takbanuaz
Effects of water temperature and feed iron level on nitrite resistance of spotted seabass <em>（Lateolabrax japonicus）</em>
No full textAfter 56 days of culture experiment, spotted seabass (Lateolabrax japonicus) (10 fish per tank) fed diets with similar dietary iron levels (63, 188, and 554 mg/kg) were subjected to a 24-hour nitrite stress challenge at 27 °C and 33 °C, respectively. Nitrite stress significantly reduced the levels of hematocrit (HCT), red blood cell (RBC) and hemoglobin (Hb). The reduction in the 33 ℃ group was greater than that in the 27 ℃ group, and the decrease in the 63 mg/kg iron level group was the largest. The main impact analysis revealed that when the dietary iron level rose from 63 mg/kg to 554 mg/kg, the contents of red blood cell (RBC), white blood cell (WBC), and hemoglobin (Hb) in the blood and the activities of total antioxidant capacity (T-AOC) and catalase (CAT) in the serum significantly increased (P< 0.05). The group with an iron level of 188 mg/kg showed a considerably lower serum malondialdehyde (MDA) content than the group with an iron level of 63 mg/kg (P< 0.05). The 63 mg/kg iron level group observed substantial decreases (P< 0.05) in hemoglobin (Hb) and total antioxidant capacity (T-AOC) under 27 °C, but dietary 188 and 554 mg/kg iron mitigated this phenomenon.
Iron deficiency and high temperatures facilitated the formation of methemoglobin (MetHb). This study demonstrated that spotted seabass is more susceptible to the physiological harm caused by nitrite at 33 ℃ than at 27 ℃. Iron deficiency exacerbated the risk of hemocytopenia, oxidative stress and hypoxia. Dietary iron fortification could enhance tolerance by enhancing antioxidant capacity and blood homeostasis
