氨和空气暴露对大鳞副泥鳅肝脏抗氧化能力的影响

将大鳞副泥鳅(Paramisgurnus dabryanus)分别暴露于30 mmol/L NH4C1溶液和空气中,以评价氨和空气暴露对其肝脏抗氧化能力的影响.结果显示,氨暴露并未引起大鳞副泥鳅肝脏超氧化物歧化酶(superoxide dismutase,SOD)活性的显著变化,仅空气暴露12h后,大鳞副泥鳅肝脏SOD...     

氨和空气暴露对大鳞副泥鳅血浆皮质醇、 乳酸及血糖含量的影响

为研究氨和空气暴露对大鳞副泥鳅血浆应激指标的影响,实验设置空气暴露组、氨暴露组和对照组3个组,将大鳞副泥鳅(Paramisgurnus dabryanus)分别置于圆形塑料盆(空气暴露组)、10 L 30 mmol/L NH_4Cl溶液(氨暴露组)、10 L纯水(对照组),3个组的暴露时间均设置为0、12、24、 48、72及96 h,每个暴露时间点均设置三个平行组,每个平行各装4尾。每个暴露时间点结束时,尾静脉取血测定血液生理指标。结果显示:空气暴露前24 h和氨暴露前12 h,大鳞副泥鳅血浆皮质醇含量均显著增加,而随后则显著下降。氨和空气暴露后,大鳞副泥鳅血糖含量均显著上升。空气暴露大鳞副泥鳅48 h内,其血浆乳酸含量的变化并不显著,而随后则显著上升。氨暴露条件下,大鳞副泥鳅血浆乳酸含量迅速上升,并在暴露12 h时达到最大值;随后迅速降至对照组水平。结果表明,氨和空气暴露可通过提高血浆皮质醇、血糖和乳酸含量以引起大鳞副泥鳅第一和第二阶段应激反应。血浆中皮质醇含量在氨和空气暴露一段时间后显著降低,在氨暴露72 h后降至对照水平,说明大鳞副泥鳅拥有某些特殊的氨耐受策略以应对体内外氨应激。     

泥鳅和大鳞副泥鳅营养成分分析

对泥鳅和大鳞副鳅肌肉的营养成分进行测定。泥鳅的水分,灰分,脂肪,蛋白质的含量分别为７８．２１％、１．１２％、２．３１％、１７．５５％;大鳞副泥鳅的分别为７８．８０％、１．１３％、２．５７％、１７．４０％。它们的１７种氨基酸含量分别为１６．１１％和１３．７８％,其中９种必需氨基酸含量分别为７．０２％和６．２９％。,经比较分析,两种泥鳅营养丰富,其中,泥鳅的营养价值要高于大鳞副泥鳅。     

大鳞副泥鳅胚胎发育观察

使用显微镜连续观察大鳞副泥鳅的胚胎发育过程,描述并摄像记录胚胎发育各时期的形态特征和生物学事件。结果显示,大鳞副泥鳅的受精卵为粘性卵,呈淡黄色,膜径约1.3 mm,卵质分布均匀;胚胎发育过程可分为受精卵、卵裂、囊胚、原肠胚、神经胚、器官发生和孵化7个阶段,共26个典型时期;24℃水温下,受精卵约24小时孵出仔鱼,初孵仔鱼体长约5mm。     

大鳞副泥鳅胚胎发育观察

大鳞副泥鳅 (Ｐａｒａｍｉｓｇｕｒｎｕｓｄａｂｒｙａｎｕｓ)属于鱼纲 ,鲤形目 ,鳅科。广泛分布于中国、日本、朝鲜、俄罗斯和东南亚等国家和地区 ,在我国主要分布在东部地区的河、沟渠、水田、池塘、湖泊、水库等天然水域。关于大鳞副泥鳅胚胎发育研究 ,国内相关报道甚少 ,本文对大鳞副泥鳅胚胎发育进行较深入的研究 ,为大鳞副泥鳅的选种、繁育、养殖及相关科学研究提供资料。1　材料与方法1 1　实验材料与仪器性成熟的大鳞副泥鳅 (购自福州水产批发市场 )、ＬＲＨ -Ａ、利血平、 0 65 %生理盐水、注射器、培养皿、鱼缸、池塘水、解剖镜…     

四倍体泥鳅、二倍体泥鳅和大鳞副泥鳅营养成分分析

利用常规肌肉营养分析方法测定了四倍体泥鳅、二倍体泥鳅和大鳞副泥鳅的肌肉营养成分。结果表明：四倍体泥鳅、二倍体泥鳅和大鳞副泥鳅肌肉中（鲜重）蛋白质含量分别为18．68％、18．69％和18．20％;脂肪含量分别为0．796％、0．106％和1．203％;水分含量分别为79．81％、79．52％和78．40％;灰分含量分别为0．951％、1．188％和1．162％。三种泥鳅肌肉中都含有常见的17种氨基酸,其中包括9种人体必需氨基酸;氨基酸总量（占鲜重）分别为17．57％、18．11％和17．47％;必需氨基酸总量分别为7．84％、7．98％和7．76％;必需氨基酸的构成比例符合FAO／WHO的标准。鲜味氨基酸含量分别为6．98％、7．33％和6．95％。经比较分析,四倍体泥鳅和二倍体泥鳅肌肉中蛋白质含量、17种氨基酸含量、氨基酸总量和必需氨基酸总量均很接近,但都明显高于大鳞副泥鳅。     

四倍体和二倍体泥鳅及大鳞副泥鳅营养成分分析

利用常规肌肉营养分析方法测定了四倍体泥鳅、二倍体泥鳅和大鳞副泥鳅的肌肉营养成分。结果表明: 四倍体泥鳅、二倍体泥鳅和大鳞副泥鳅肌肉中蛋白质含量(鲜重) 分别为18. 68%、18. 69%和18. 20%; 脂肪含量分别为0. 796%、0. 106%和1. 203%; 水分含量分别为79. 81%、79. 52%和78. 40%; 灰分含量分别为0. 951%、11188%和1. 162%。3种泥鳅肌肉中都含有常见的17种氨基酸, 其中包括9种人体必需氨基酸。氨基酸总量(占鲜重)分别为17. 57%、18. 11%和17. 47%; 必需氨基酸总量分别为7. 84%、7. 98% 和7. 76%, 必需氨基酸的构成比例符合FAO /WHO 的标准。鲜味氨基酸含量分别为6. 98%、7. 33%和6. 95%。经比较分析, 四倍体泥鳅和二倍体泥鳅肌肉中蛋白质含量、17种氨基酸含量、氨基酸总量和必需氨基酸总量均很接近, 但都明显高于大鳞副泥鳅。     

四倍体和二倍体泥鳅及大鳞副泥鳅营养成分分析

利用常规肌肉营养分析方法测定了四倍体泥鳅、二倍体泥鳅和大鳞副泥鳅的肌肉营养成分.结果表明:四倍体泥鳅、二倍体泥鳅和大鳞副泥鳅肌肉中蛋白质含量(鲜重)分别为18.68%、18.69%和18.20%;脂肪含量分别为0.796%、0.106%和1.203%;水分含量分别为79.81%、79.52%和78.40%;灰分含量分别为0.951%、1.188%和1.162%.3种泥鳅肌肉中都含有常见的17种氨基酸,其中包括9种人体必需氨基酸.氨基酸总量(占鲜重)分别为17.57%、18.11%和17.47%;必需氨基酸总量分别为7.84%、7.98%和7.76%,必需氨基酸的构成比例符合FAO/WHO的标准.鲜味氨基酸含量分别为6.98%、7.33%和6.95%.经比较分析,四倍体泥鳅和二倍体泥鳅肌肉中蛋白质含量、17种氨基酸含量、氨基酸总量和必需氨基酸总量均很接近,但都明显高于大鳞副泥鳅.     

大鳞副泥鳅池塘苗种培育试验

大鳞副泥鳅幼苗放养量在60万尾／667m^2，经过30d的培育，体长可达4～6cm，成活率达40％左右，然后进入成鳅养殖阶段。试验着重解决大鳞副泥鳅的池塘苗种培育技术和苗种培育成活率低的难题，为鳅苗的培育找到适口的饵料。     

Gynogenesis and sex determination in large-scale loach Paramisgurnus dabryanus (Sauvage)

Gynogenesis was induced using heterologous sperms in large-scale loach, Paramisgurnus dabryanus (Sauvage), in which a ZW/ZZ sex determination was previously proposed. Three microsatellite loci were used to monitor exclusive maternal inheritance of gynogenetic progenies. The results showed that high percentages of meiogynogens were produced at 4 min post-fertilization and mitogynogens were produced at 18 min post-fertilization by heat shocks, while meiotic gynogenesis was induced by cold shocks within a wide period and high heterozygosity was even observed in gynogens produced at 24 min post-fertilization. The sex ratios of the F₁ progenies in three gynogenetic families were significantly deviated from 1:1 expectation with a female bias in two families and a male bias in one family (P < 0.05), and the other four gynogenetic families showed approximate 1:1 sex ratios. Moreover, the self-mating between gynogenetic F₁ progenies and mating between gynogenetic F₁ progenies and normal individuals produced all-female progenies or identical proportions of females and males. The data of sex ratios generally confirmed that the sex determination in large-scale loach was determined by the putative ZW/ZZ system, and the possible reasons causing the biased sex ratios are discussed.     

蚯蚓粉替代鱼粉对大鳞副泥鳅生长、肌肉成分、血清生化指标及免疫性能的影响

以初始体重为(3.86±0.23)g的大鳞副泥鳅(Paramisgurnus dabryanus)为试验对象,研究蚯蚓(Eisenia foetida)粉替代鱼粉对其生长、肌肉成分、血清生化指标及免疫性能的影响。以0代替鱼粉为对照组,用蚯蚓粉替代25%、50%、75%、100%的鱼粉配制成5组等氮等能饲料,在网箱中进行10周的养殖试验。结果显示,饲料中的蚯蚓粉替代鱼粉对大鳞副泥鳅的存活率无显著影响;随着替代水平的升高,饲料系数、增重率升高(P0.05),肥满度、肝体比降低(P0.05)。各组间脾体比、特定生长率均无显著性差异;75%和100%替代组肌肉粗脂肪含量显著高于对照组(P0.05),100%替代组粗蛋白和水分含量显著低于对照组(P0.05)。随着饲料中蚯蚓粉水平的上升,鱼体肌肉蛋白质的精氨酸、胱氨酸、天门冬氨酸含量升高(P0.05),脯氨酸、组氨酸、蛋氨酸、苏氨酸、苯丙氨酸含量显著降低(P0.05);各组间血清谷丙转氨酶活力、高密度脂蛋白胆固醇含量、脂肪酶和淀粉酶活性均无显著性差异(P0.05)。随着代替水平的上升,血清甘油三酯和总胆固醇含量显著升高(P0.05),谷草转氨酶显著降低(P0.05);随着替代水平的继续上升,肝胰脏过氧化氢酶、谷胱甘肽过氧化物酶、溶菌酶活力下降,肝胰脏丙二醛含量、碱性磷酸酶活力、攻毒后的发病率和死亡率上升。各组间的肝胰脏总超氧化物歧化酶活力和总抗氧化能力均无显著性差异(P0.05)。研究表明,本实验条件下,蚯蚓粉可部分替代(22%)饲料鱼粉而不影响大鳞副泥鳅的生长和存活,且能提高鱼体肌肉成分,有效预防肝胰脏损伤和过氧化,但显著降低了鱼类免疫性能(P0.05)。     

Dopamine inhibits gonadotropin secretion in the Chinese loach (Paramisgurnus dabryanus)

The effects of dopamine on gonadotropin (GtH) secretion in sexually mature Chinese loach were investigated. Spontaneous secretion of GtH was inhibited within 1 h following an intramuscular injection of dopamine (100 g/g body wt). Similarly, dopamine (50 and 100 g/g body wt) caused a significant reduction in serum GtH in fish with elevated GtH levels as a result of pretreatment with gonadotropin-releasing hormone (GnRH) analogs either alone or in combination with the dopamine receptor antagonist domperidone. In summary, the present study provides direct evidence that dopamine functions as a gonadotropin-release inhibitory factor in the Chinese loach by blocking spontaneous and GnRH-stimulated GtH release.     

Metabolic activity variations in the sea urchins (Paracentrotus lividus) treated with magnesium and subjected to handling stress and aerial exposure

This study assessed the impact of the use of magnesium chloride as a relaxant for the echinoid Paracentrotus lividus on the metabolic activity of individuals subjected to handling stress and aerial exposure. The variation in the gonad moisture content and biochemical composition was compared in sea urchins (P. lividus) treated with magnesium and untreated controls before transport and during 15 days of laboratory acclimation. Sea urchins treated with magnesium maintained higher levels of protein and carbohydrate throughout the trial in comparison with controls. However, the lipid level and fatty acid percentage remained stable during the experiment and no differences were found between treated or non‐treated sea urchins .     

Distribution of glutamine synthetase in the snapper (Pagrus auratus) and implications for the immune system

A sensitive radiotracer method was used to detect glutamine synthetase activity in fish. The distribution of glutamine synthetase activity using this method was shown to be widespread in organs and tissues of the marine finfish, snapper,Pagrus auratus. The optimum pH and temperature for glutamine synthetase activity and K_m of glutamate from the brain of the snapper are also reported. Interestingly no glutamine synthetase activity was detected in lymphoid organs, indicating, that as in the mammal, the teleostean immune system is likely to rely on glutamine in circulation for energy and nucleotide synthesis. Furthermore circulating glutamine levels fell as fish became stressed or became ill. Implications of these observations on the function of the immune system of fish are discussed.     

急性氨氮胁迫对虎斑乌贼肝脏、鳃和脑组织结构的影响

为了探讨氨氮对虎斑乌贼器官组织结构的影响,以体质量为(13.80±0.65)g的幼虎斑乌贼为对象,研究了氨氮胁迫对其肝脏、鳃和脑组织结构的影响。根据96 h的LC50实验结果设计5个梯度(0、1、3、6和12 mg/L)进行96 h的氨氮胁迫后,利用光学显微镜和透射电子显微镜观察其肝脏、鳃和脑组织结构。结果显示,在相同浓度的氨氮胁迫下,虎斑乌贼不同组织器官之间损伤程度存在差异,其中肝脏损伤的程度最大,对氨氮胁迫表现最敏感,其次是鳃组织和脑组织,组织器官损伤程度与氨氮浓度呈现正相关。氨氮胁迫浓度越大或胁迫时间越长,肉眼观察发现肝脏颜色越鲜红,肿胀和易糜烂程度越明显,可通过肉眼观察肝脏颜色和肿胀程度初步判断机体氨中毒程度;氨氮胁迫后,对肝脏和鳃组织造成较为严重的损伤,可能是虎斑乌贼氨中毒致死的原因。当氨氮高于或等于6 mg/L时胁迫96 h后,通过显微观察发现肝小叶轮廓模糊不完整、排列不紧密和胞浆疏松透明,大量的细胞核溶解,细胞出现空泡化,肝血窦扩张;通过电镜观察发现细胞核皱缩变形、核仁消失、线粒体嵴紊乱、线粒体空泡化、线粒体外室肿胀,高尔基体数量减少;显微观察发现鳃组织的泌氯细胞和上皮细胞核溶解,细胞出现空泡化、排列紊乱,鳃丝肿胀淤血、轮廓模糊不完整,并出现坏死脱落和缺损;通过透射电镜观察,发现细胞核皱缩、核膜破损和细胞核裂解,线粒体出现了皱缩变形、空泡化和不完整破损现象;观察脑组织的神经团和视叶,未发现脑组织的细胞有显著损伤。     

Changes in physiological parameters involved in glutamine and urea synthesis in Pacific white shrimp,Litopenaeus vannamei,fed Ampithoe sp. meal and exposed to ammonia stress

Two dietary formulas containing 0% (D0 group) and 33% (D33 group) Ampithoe sp. meal were fed to Litopenaeus vannamei for 42 days, and then, an ammonia stress test was performed to explore the mechanism by which dietary Ampithoe sp. meal supplementation improves the ammonia tolerance of shrimp. The changes in key enzyme activities and biochemical substances involved in glutamine and urea synthesis in shrimp under ammonia stress were investigated. The cumulative mortality in the D0 group and D33 group was 62.22% and 44.44% respectively. With the prolongation of ammonia exposure, the ammonia concentration in the haemolymph of both groups increased, but that of the D33 group was significantly lower than that of the D0 group. The glutamate dehydrogenase (GDH) activity, glutamine concentration and urea‐N concentration in the haemolymph of the D33 group were significantly higher than those of the D0 group. In the gills of the D33 group, the glutamine concentration, arginase (ARG) activity and urea‐N concentration were significantly higher than those of the D0 group. In the hepatopancreas of the D33 group, the glutamine synthetase (GS) activity, glutamine concentration and urea‐N concentration were significantly higher than those of the D0 group. In the muscle of the D33 group, the GDH activity, GS activity, glutamine concentration and ARG activity were significantly higher than those of the D0 group. Consequently, our results indicated that dietary Ampithoe sp. meal supplementation could enhance glutamine and urea synthesis, thereby reducing ammonia accumulation in organisms, resulting in the improvement of ammonia tolerance in L. vannamei.