两种养殖模式下黄条鰤幼鱼消化道菌群对生长的微生态调控作用

探究了工厂化、网箱养殖模式对黄条鰤(Seriola lalandi)幼鱼生长性能及消化道菌群的影响, 通过 16S rRNA 高通量测序和生物信息学方法, 分析了两种养殖模式下黄条鰤幼鱼消化道(胃、幽门盲囊、肠道)、饵料及养殖水中的菌群结构特征及其互作关系。结果显示, 本实验条件下, 网箱养殖黄条鰤幼鱼较工厂化养殖鱼生长性能显著提升; 在黄条鰤幼鱼消化道菌群方面, 门水平上的拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)和属水平上的拟普雷沃氏菌属(Alloprevotella)、拟杆菌属(Bacteroides)在网箱养殖模式中其丰度值高于工厂化养殖模式, 其中拟杆菌属仅出现于网箱养殖模式且呈现显著性差异; Beta 多样性分析显示消化道菌群更多受到饵料菌群的影响, 受水环境影响相对较小。KEGG 注释分析表明两种养殖模式的差异菌群中, 网箱养殖幼鱼消化道菌群主要参与磷酸转移酶系统 (PTS)和 NOD 样受体信号通路, 而工厂化养殖幼鱼为碳水化合物代谢和类胡萝卜素合成通路。本研究表明, 环境菌群中, 饵料菌群对消化道菌群的影响大于养殖水体菌群; 消化道微生物群落通过调整其组成结构从而改变菌群功能通路的方式, 积极参与两种养殖模式下黄条鰤幼鱼生长机能差异的调控。因此, 网箱养殖鱼表现出更快速的生长性能可能是由于机体内的菌群产生了更多的短链脂肪酸并诱导 IGF-1 等生长相关功能基因的表达, 从而促进机体的营养吸收和生长。本研究预期结果将为黄条鰤专用配合饲料的研制和健康养殖技术开发提供微生态理论支撑。     

养殖水环境中氮的循环与平衡

养殖水环境中，由于人为的介入和影响。使得水体中氮的各种形态转化和循环过程中发生了改变。笔者详细地介绍了养殖水环境中氮的各种存在形态，及其相互之间的转化和循环过程，同时总结了前人研究和提出的各种养殖水环境中氮的物质平衡模型，为优化水产养殖和保护水环境提供科学依据。     

松江鲈肾组织细胞系生物学特性研究

在25℃、5%CO_2实验室条件下,于20%FBS-DMEM/F12培养基中培养松江鲈肾组织细胞系,以研究其生物学特性。第75代松江鲈肾组织细胞传代培养后,0～2 d处于潜伏期,2～4 d进入对数生长期,4～6 d进入稳定期,其群体倍增时间为55.2 h。经液氮冷冻保藏1月后,复苏细胞的存活率为(90.8±1.37)%。35代松江鲈肾组织细胞的染色体数为2n=40,核型公式为K(2n)=16m+10sm+14t。病毒敏感性试验表明,松江鲈肾组织细胞对鱼类诺达病毒不敏感,对鲤春病毒血症病毒敏感,测定病毒滴度为10^6.53/mL。镉离子敏感性试验显示,松江鲈肾细胞存活率随着氯化镉浓度的升高而降低,半致死浓度为(130±9.1)μmol/L,可用来作为镉离子检测的生物学指标。     

青岛市崂山近岸海域水质营养现状与评价

根据2005年7、9月和2006年9、11月对青岛市崂山近岸海域的4次调查结果,分析并评价了该海域的营养状况。结果表明,表层无机氮、PO4-P和COD含量,仰口至港东、石老人、流清河湾海域略高于其他水域。底层无机氮、PO4-P均为仰口至港东水域含量较高,COD为太清宫湾水域含量较高,其余水域分布相对较均匀。从营养结构分析,7和11月该海域表、底层,N与P相比显得相对缺乏;9月表层,N与P相比也显得相对缺乏;9月底层N/P比值接近16∶1,氮、磷均不受限制。从营养状况看,除2005年9月份该海域水质处于富营养化水平外,其他调查月份水质均未达到富营养化。     

不同宰杀方式对大菱鲆保鲜的影响

通过研究不同宰杀方式对大菱鲆鱼肉鲜度指标的影响,以寻找一种较好的宰杀方式来提高大菱鲆保鲜效果。实验采用4种方式宰杀大菱鲆:脉冲电击,CO2麻醉,放血,打头;宰杀后置于0℃下保藏,测定各组样品的K值、乳酸含量、pH值随时间的变化。实验结果:在保藏过程中,打头致死组K值升高最缓慢,0h时乳酸含量最低为1.5362mg/g(电击组、CO2麻醉组、放血组的乳酸含量分别为1.7415mg/g、2.4646mg/g、1.9912mg/g),0h时pH值最高为7.14(电击组、CO2麻醉组、放血组的pH值分别为6.99、6.78、6.91)。打头致死最有利于保鲜,其次为电击。     

Differences in uptake and killing of pathogenic and non‐pathogenic bacteria by haemocyte subpopulations of penaeid shrimp,Litopenaeus vannamei, (Boone)

Phagocytosis is an important function of both invertebrate and vertebrate blood cells. In this study, the phagocytic activity of haemocyte subpopulations of penaeid shrimp, Litopenaeus vannamei, (Boone), against pathogenic and non‐pathogenic particles was investigated in vitro. The haemocytes of penaeid shrimp were firstly separated by centrifugation on a continuous density gradient of iodixanol into four fractions with five subpopulations (sub), of which sub 1 (hyalinocytes) and sub 4 (semi‐granulocytes) have the main function in phagocytosis of both pathogenic and non‐pathogenic bacteria as well as fluorescent polystyrene beads. It was found that these haemocyte subpopulations engulfed virulent Vibrio campbellii and Vibrio harveyi at a higher rate than non‐virulent Escherichia coli and polystyrene beads. When these bacteria were mixed with shrimp haemocyte subpopulations and incubated for 180 min, the percentage of viable intracellular V. campbellii (25.5 ± 6.0%) recovered was significantly higher than the percentage recovered from V. harveyi (13.5 ± 1.1%). No viable intracellular E. coli was observed in this study. In contrast to V. harveyi and E. coli, V. campbellii containing endosomes did not acidify in time. Incubation of haemocyte subpopulations with the most virulent V. campbellii strain resulted in a significant drop in haemocyte viability (41.4 ± 6.3% in sub 1 and 30.2 ± 15.1% in sub 4) after 180 min post‐inoculation in comparison with the less virulent V. harveyi (84.1 ± 5.6% in sub 1 and 83.4 ± 4.1% in sub 4) and non‐virulent E. coli (92.7 ± 2.8% in sub 1 and 92.3 ± 5.6% in sub 4) and polystyrene beads (91.9 ± 1.6% in sub 1 and 84.4 ± 3.4% in sub 4). These findings may be a valuable tool for monitoring shrimp health and immunological studies.     

Phenotypical parameters as a tool to evaluate the immunostimulatory effects of laminarin in Oncorhynchus mykiss

Laminarin is a β‐glucan from the brown algae Laminaria digitata (J.V. Lamour), which can activate innate immune responses. With the aim of developing a strategy to evaluate specific phenotypical parameters of the effects of laminarin in trout innate immunity, we (i) fed fish with laminarin‐supplemented diet (0.2 g kg^?1 day^?1) for 21 days and (ii) treated fish with a single dose of intraperitoneal injected laminarin (0.08 g kg^?1 fish). The evaluation of cellular and humoral immune parameters was established at phenotypic level by the phagocytic activity of headkidney macrophages and detection of inflammatory cytokines in head kidney and gill tissue by indirect ELISA. Results showed that both delivery methods of laminarin produce an increase in the phagocytic activity in head kidney macrophages and a significant increase in the production of TNFα and IL‐8 in gill tissue at day 21. Additionally, some of these parameters were significantly correlated (P < 0.025), which places them as new potential combined markers to detect activation of trout defense mechanisms by laminarin. These results highlight the importance of developing new protocols to quantitate immune parameters, in order to evaluate immunostimulants in fish farming.     

基于线粒体Cyt b基因序列的棘头梅童鱼种群遗传结构

选取线粒体细胞色素b (cytochrome b,Cyt b)基因序列作为分子标记,分析了中国沿海棘头梅童鱼(Collichthys lucidus)的种群遗传结构.2019年9-11月在中国沿海9个采样点共采集棘头梅童鱼342尾,共检测到174个单倍型.通过构建单倍型网络连接图和单倍型进化树发现,棘头梅童鱼可分为北方...     

Phenotypic differences may limit the potential for habitat restoration involving species translocation: a case study of shape ecophenotypes in different populations of Modiolus modiolus (Mollusca: Bivalvia)

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Effects of glycinin on growth performance,immunity and antioxidant capacity in juvenile golden crucian carp,Cyprinus carpio × Carassius auratus

This study was designed to examine the effects of glycinin on growth, digestive ability, immune responses, antioxidant capacity and gene expression levels of golden crucian carp. Golden crucian carp were fed diets containing glycinin at 0, 30, 60, 90 and 120 g/kg, respectively, for 8 weeks. Body weight, weight gain percentage, specific growth rate and feed efficiency ratio were negatively related to the content of glycinin in diet. Activities of protease, acid phosphatase, alkaline phosphatase, lysozyme in hepatopancreas, and activities of catalase, glutathione peroxidase, superoxide dismutase, and total antioxidant capacity in the proximal intestine, mid intestine, distal intestine and hepatopancreas were negatively related to the content of glycinin in diet, whereas malondialdehyde in proximal intestine, mid intestine, distal intestine and hepatopancreas increased directly with the content of glycinin in diet. Furthermore, the relative expressions of TNF‐α and IL‐1β in proximal intestine, mid intestine and distal intestine increased directly with the content of glycinin in diet, whereas the relative expressions of TNF‐α and IL‐1β in hepatopancreas were negatively related to the content of glycinin in diets. The relative expressions of IL‐10 in proximal intestine, mid intestine, distal intestine and hepatopancreas all were negatively related to the content of glycinin in diets. In conclusion, reductions in growth, immunity and antioxidant capacity, intestine inflammation with dysfunction of digestive system occurred in golden crucian carp that fed a diet containing glycinin at 30 g/kg or higher after 8 weeks.