运输密度和时间对黑尾近红鲌皮质醇、乳酸、糖元含量的影响

为了确定黑尾近红鲌仔稚鱼的适宜运输密度,实验选取平均体长为(27.08±3.09) mm、平均体质量为(0.11±0.04) g的黑尾近红鲌仔稚鱼作为实验对象,采用氧气袋运输,研究了不同运输密度(20、40和80 g/L)下2h、4h、6h、8h和10h后黑尾近红鲌全鱼皮质醇、乳酸、糖元含量及氧气袋内水质的变化。结果显示:运输后各组黑尾近红鲌的平均存活率均在99%以上,但不同密度之间差异显著(P<0.05);各组水体总氨氮浓度均随运输时间显著升高,而水体pH均随运输时间显著降低,且不同运输密度间差异显著(P<0.05);低密度组水体DO浓度(14.20—20.93 mg/L)在不同运输时间均显著高于高密度组(2.42—2.88 mg/L; P<0.05)。各组全鱼皮质醇含量均呈现出先升高后降低的趋势,运输4h和6h时显著高于其它运输时间(P<0.05),且不同运输密度间差异显著(P<0.05);各组全鱼乳酸含量均随着运输时间显著升高(P<0.05),但不同密度之间无显著差异(P>0.05);各组全鱼糖元含量在运输2h时显著降低(P<0.0...     

温度对中华鲟(Acipenser sinensis)幼鱼麻醉效果的影响

以MS-222为麻醉剂,研究了水温(15、20和25℃)对中华鲟幼鱼有效麻醉剂浓度、入麻和复苏时间、最长麻醉保活时间、最终麻醉状态的影响,以及气温(4、12和20℃)对中华鲟幼鱼最长空气暴露保活时间和复苏时间的影响。结果表明:当水温为15、20和25℃时,MS-222麻醉中华鲟幼鱼的有效质量浓度分别为100～240、80～140和60～130 mg·L~(-1),最长麻醉保活时间分别为11 min、7 min和70 s;随着水温的升高,中华鲟幼鱼的入麻时间和最长麻醉保活时间均显著下降;而复苏时间呈先降后升的趋势,二者之间不存在显著的相关性;实验鱼的最终麻醉程度随MS-222浓度的升高而增大;随着气温的升高,中华鲟幼鱼的最长空气暴露保活时间显著下降,而复苏时间显著增加;当气温为4、12和20℃时,最长空气暴露保活时间分别为60、28和14 min;水温对中华鲟幼鱼的麻醉效果产生了显著影响,气温对中华鲟的空气暴露保活时间和复苏时间也产生了显著影响,在中华鲟的麻醉过程中应充分考虑水温对麻醉效果的影响,在对入麻中华鲟进行离水操作时,应充分考虑气温对中华鲟空气暴露保活时间的影响,避免鱼体出现意外损伤或死亡。     

模拟运输对异育银鲫血液生理生化指标、体色和肉质的影响

实验以异育银鲫“中科3号”[Carassis gibelio var. CAS III, 平均体重(116.46±2.09) g)]为研究对象, 通过模拟汽车运输振动台模拟4h运输, 研究模拟运输对异育银鲫血液生理生化指标、体色和肉质及水质的影响。研究结果表明: 经过模拟运输后, 运鱼袋内水体氨氮显著升高(P<0.01), pH显著下降(P<0.05), 溶解氧含量升高(P<0.05)。模拟运输后异育银鲫血浆中皮质醇、葡萄糖和丙二醛浓度显著升高(P<0.01); 乳酸浓度显著降低(P<0.01); 谷胱甘肽过氧化物酶活力显著降低(P<0.05); 超氧化物歧化酶和过氧化氢酶活力降低但差异不显著(P>0.05)。在模拟运输4h后, 异育银鲫背部亮度值(L*)显著降低(P<0.01), 黄色值(b*)在背部和侧线部较模拟运输前显著降低(P<0.01), 在腹部较模拟运输前显著降低(P<0.05), 侧线部和腹部的亮度值(L*), 以及背部、侧线部和腹部的红色值(a*)下降但差异不显著(P>0.05)。在模拟运输后, 异育银鲫背肌内聚性、咀嚼性和回复性显著降低(P<0.05), 硬度、胶黏性、弹性和黏性变化但差异不显著(P>0.05)。实验结果表明, 4h模拟运输能够引起运鱼袋水体水质情况改变, 诱导异育银鲫鱼体的应激反应, 导致实验鱼体色和鱼肉品质相关指标的变化, 降低了鱼肉品质部分指标。     

美洲鲥应激后皮质醇激素和血液生化指标的变化

比较了美洲鲥(Alosa sapidissima)1龄幼鱼因环境改变和运输引起的血清皮质醇激素浓度和血液生化指标变化。结果表明,美洲鲥转入较小容器中后血清皮质醇含量迅速增加到对照组[(2.05±1.48)ng/ml,n=10]的10倍左右。运输2 h后美洲鲥血清皮质醇激素含量[(41.97±17.92)ng/ml,n=9]比运输前显著上升20倍左右。2 h运输后总蛋白、白蛋白、谷丙转氨酶、碱性磷酸酶、Ca2 比对照组极显著增加(P<0.01),白球比和乙酸胆碱酯酶、血糖、K 显著增加(P<0.05),谷草转氨酶和乳酸脱氢酶无显著变化(P>0.05),Cl-显著低于对照组(P<0.01)。血液指标明显变化表明,美洲鲥运输应激后,心脏和肝脏等组织一定程度受损,可能导致了较高的死亡率。     

中华绒螯蟹在不同pH下氨氮排泄和血淋巴含氮成分的变化

为研究不同环境pH对中华绒螯蟹(Eriocheir sinensis)氮排泄的影响,将性成熟的中华绒螯蟹置于pH 4.5、6.0、7.5、9.0和10.5的环境中,24h后测定血淋巴中不同含氮成分的变化.结果表明,环境pH从4.5到9.0,中华绒螯蟹的氨氮排泄无显著变化,当pH升高到10.5时,氨氮排泄受到显著抑制;同时环境pH的升高还导致血淋巴pH上升,在pH 10.5时,血淋巴氨氮、尿素氮和尿酸的含量也显著上升分别达到(5.90±0.61) μg/mL、(2.47±0.14)μg/mL和(0.096±0.002)μmol/mL.实验结果还显示,高pH环境影响中华绒螯蟹的蛋白质和氨基酸的代谢水平,降低血淋巴总蛋白和血蓝蛋白的含量,而游离氨基酸含量显著增加,它们的变化可能同机体的氨中毒解毒机制有关.     

电麻醉对圆口铜鱼幼鱼行为及血液生化指标的影响

探讨了低压直流电麻醉对圆口铜鱼Coreius guichenoti幼鱼(体质量300~420 g)行为及血液生化指标的影响。试验设置电麻醉组(30 V)和对照组(0 V)。电麻醉组试验鱼在电麻醉开始3 s内的身体行为反应最为剧烈,25 s内进入全麻状态。麻醉8 min后停止,试验鱼能迅速恢复平衡但活动迟缓。电麻醉组试验鱼的入麻时间为17.4 s±4.5 s。除电麻醉组的血清葡萄糖水平显著高于对照组之外,2组的其他常规血液生化指标差异均无统计学意义,表明电麻醉对圆口铜鱼幼鱼血液生化指标的影响有限。研究结果表明,短时间低压直流电麻醉是一种入麻时间短、复苏时间快、对机体伤害较小的圆口铜鱼幼鱼麻醉方式。     

似刺鳊鮈外周血细胞显微结构和血清生化指标的初步研究

似刺鳊(鮈)(Paracanthobrama guichenoti)外周血细胞可分为红血细胞、嗜中性粒细胞、单核细胞及大、小淋巴细胞和血栓细胞,未发现嗜酸性和嗜碱性粒细胞.外周血液中可观察到少量未成熟的及正在分裂的红血细胞.白细胞中,血栓细胞体积最小,嗜中性粒细胞体积最大;数量上,血栓细胞最多,而大淋巴细胞则最少.似刺鳊(鮈)血清生化指标测定结果显示,谷丙转氨酶(ALT)、胆固醇(CHOL)和总蛋白(TP)变化范围较大,且谷草转氨酶(AST)的水平较高,似刺鳊(鮈)雄鱼的血液生化指标相应值均显著低于雌鱼(P<0.05).     

抗运动性疲劳剂作用研究进展

抗疲劳研究是当下研究的热点.本文结合目前抗疲劳研究中最常使用的方法:游泳实验(weight-loaded swimming test or forced swim test)、旋转棒实验(rotarod test)以及各种生化指标如血乳酸、血尿素氮、肌糖元、肝糖原等含量的测定,总结目前抗疲劳物质活性组分的基本作用机制,...     

猪小肠微生物对不同蛋白源的体外发酵特性比较

【目的】采用体外发酵技术比较小肠微生物对不同蛋白源的发酵规律。【方法】以成年猪的十二指肠、空肠和回肠内容物为接种物,以豆粕、菜粕或鱼粉水解物上清液为氮源底物,于发酵的0、4、8、12 h分别测定发酵液p H、微生物蛋白、氨氮和挥发性脂肪酸含量,同时提取细菌DNA并进行定量分析。【结果】添加含氮底物的空肠组和回肠组氨氮浓度和菌体蛋白浓度均相对增加,尤其是酶解菜粕组菌体蛋白合成量较高;十二指肠组菌体蛋白浓度以及氨氮含量不断减少。各发酵组乳酸和挥发酸快速积累,4–8 h积累量最大;8 h后空肠组和回肠组乳酸和挥发酸含量相对稳定,而十二指肠组后期丙酸含量增加约2 mmol/L,并伴随着乳酸含量的相对减少。同时,各组中总细菌、拟杆菌门、厚壁菌门和乳酸杆菌数量相对增加,且略高于无氮组,但不同蛋白源组间无显著差异。【结论】在体外培养条件下,空肠和回肠微生物具有相似的发酵规律,均能快速利用培养液中的含氮物质合成菌体蛋白;十二指肠微生物具有较强的产挥发酸能力,能够转化乳酸并大量产生丁酸和丙酸,这有利于宿主营养功能和肠道健康。     

重组白介素2对红鳍东方鲀的血液生化指标及免疫指标的影响

为研究重组白介素2(Recombinant interleukin-2,r IL-2)对红鳍东方鲀(Takifugu rubripes)血液生化指标及免疫指标的影响,选用体重为(205.9±30.5)g的红鳍东方鲀进行了重组白介素2的免疫应答实验。设计r IL-2免疫剂量为2.5、5、7.5、10μg,并在免疫后的4 h、8 h和12 h进行采血。结果表明:经r IL-2免疫后红鳍东方鲀血清中尿素氮含量在各个浓度组的8 h时间点显著高于同组内其它时间点(P<0.05),4 h时间点甘油三酯含量有随着免疫浓度增加而增加的趋势,谷草转氨酶活性在8 h时间点要显著高于其他时间点(P<0.05),2.5μg、5μg浓度组过氧化氢酶的活性在4 h时间点显著高于其他各组(P<0.05),对免疫球蛋白的含量也有显著影响。本研究发现,r IL-2的免疫可引起血液生化指标和免疫指标的变化,尤其是超氧化物歧化酶和谷草转氨酶的变化较为显著(P<0.05),可在一定程度上促进红鳍东方鲀的免疫反应。     

氨氮胁迫下不同食性鱼类仔鱼抗氧化和非特异性免疫的差异响应

为探究氨氮胁迫对不同食性鱼类的影响,研究选取不同食性的4种鱼类(鲢Hypophthalmichthys molitrix、草鱼Ctenopharyngodon idella、团头鲂Megalobrama amblycephala和黄颡鱼Pelteobagrus fulvidraco)仔鱼为研究对象,探讨不同浓度氨氮(0、1、2和3 mg/L)短期胁迫(96h)对其生长、抗氧化和非特异性免疫响应的影响及其分子机制。结果显示:(1)氨氮胁迫导致4种仔鱼的体长生长速度呈现剂量依赖性减缓;(2)不同浓度氨氮导致4种仔鱼体内T-AOC、CAT和GPx含量显著降低(P<0.05), 2和3 mg/L氨氮暴露显著降低了草鱼、团头鲂和黄颡鱼仔鱼体内SOD活力(P<0.05),仅检测到黄颡鱼gpx及鲢sod转录水平出现显著性下调(P<0.05);(3)在不同浓度氨氮胁迫下, 4种仔鱼相关免疫基因转录水平均呈现一定的上调,仅鲢il1β转录水平显著下降(P<0.05),相对地草鱼仔鱼LYZ含量显著性下降,黄颡鱼仔鱼LYZ含量在2 mg/L氨氮组显著性上升(P<0.05)。双因素...     

Acute effects of glyphosate herbicide on metabolic and enzymatic parameters of silver catfish (Rhamdia quelen)

Silver catfish (Rhamdia quelen; Teleostei) were exposed to commercial formulation Roundup, a glyphosate herbicide: 0 (control), 0.2 or 0.4 mg/L for 96 h. Fish exposed to glyphosate showed an increase in hepatic glycogen, but a reduction in muscle glycogen at both concentrations tested. Glucose decreased in liver and increased in muscle of fish at both herbicide concentrations. Glyphosate exposure increased lactate levels in liver and white muscle at both concentrations. Protein levels increased in liver and decreased in white muscle while levels of ammonia in both tissues increased in fish at both glyphosate concentrations. Specific AChE activity was reduced in brain after treatments, no changes were observed in muscle tissue. Catalase activity in liver did not change during of exposure. Fish exposed to glyphosate demonstrated increased TBARS production in muscle tissue at both concentrations tested. For both glyphosate concentrations tested brain showed a reduction of TBARS after 96 h of exposure. The present results showed that in 96 h, glyphosate changed AChE activity, metabolic parameters and TBARS production. The parameters measured can be used as herbicide toxicity indicators considering environmentally relevant concentration.     

氨氮对中华小长臂虾的急性毒性及非特异性免疫指标的影响

采用生物毒性实验方法研究了氨氮对中华小长臂虾的急性毒性作用, 结果表明: 在温度为(18±1)℃, pH为7.3±0.1条件下, 氨氮对中华小长臂虾24h、48h、72h、96h 的半致死浓度(LC₅₀)分别为565.47、371.16、291.16和272.50 mg/L, 安全浓度为 27.25 mg/L。转化为非离子氨的LC₅₀分别为3.74、2.45、1.93 和1.80 mg/L, 安全浓度为0.18 mg/L。根据96h 的LC₅₀和安全浓度按照等差数列设置5个氨氮浓度梯度, 分别60、100、140、180和220 mg/L, 研究氨氮胁迫对中华小长臂虾非特异性免疫指标的影响。结果显示: 在24h时, 除了220 mg/L的肌肉组织, 中华小长臂虾肝胰腺和肌肉中的超氧化物歧化酶(SOD)活性显著性高于对照组, 并具有明显的剂量效应, 在48—96h均回落到正常水平; 在24h时, 中华小长臂虾氨氮处理组中肝胰腺的酸性磷酸酶(ACP)与对照组未发生显著变化, 而碱性磷酸酶(AKP)则显著高于对照组, 在48—96h两者的140、180和220 mg/L处理组均显著低于对照组; 除了140 mg/L 处理组的ACP活性外, 肌肉中的ACP和AKP活性从24h开始就出现了显著性下降, 始终低于对照组。研究获得了氨氮对中华小长臂虾的急性毒性结果和在高氨氮胁迫下非特异性免疫指标的变化规律, 发现中华小长臂虾对氨氮具有较强的耐受性, 但高浓度的氨氮会对中华小长臂虾的免疫酶活性产生抑制作用, 研究结果可为中华小长臂虾健康养殖发展提供科学依据。     

养殖水质原位自净微生物诱导及复合应用

本文采用原位诱导有益微生物（污水菌、芽胞杆菌、硝化菌和副球菌等）,复合添加外源的有益微生物（金藻、栅藻、硅藻、芽胞杆菌、光合菌、酵母菌和EM（effective microorganisms）菌等）,在养殖水体中建立稳定的有益微生物复合菌群,使水体中亚硝酸氮和氨氮清除率分别可达100%和99%。并进一步利用这些菌群在小红鲫鱼（red crucian carp）和南美白对虾（Penaeus vannamei）养殖中进行原位水质净化应用。在小红鲫鱼养殖水质原位自净中,无需清污和换水,就可长期维持水环境完全稳定,连续养殖50 d以上,水中未检测出亚硝酸氮,氨氮低于0.2 mg/L,稳定在优质安全的养殖环境;在南美白对虾养殖中,投菌后初期水体亚硝酸氮较快下降,第10 d后氨氮浓度也降至养殖安全范围内,形成稳定安全的养殖水质环境。实验效果显著,表明微生物菌群原位水质自净技术具有推广应用前景。     

THE EFFECT OF TENSION OF DISSOLVED OXYGEN ON THE TOXICITY OF UN-IONIZED AMMONIA TO SEVERAL SPECIES OF FISH

The resistance to rapidly lethal concentrations of un-ionized ammonia ranging from about 2.0 to 8.8 p. p. m. N was determined for rainbow trout ( Salmo gairdnerii Richardson), perch ( Perca fluviatilis L.), roach ( Rutilus rutilus (L.)), and gudgeon ( Gobio gobio (L.)) in tensions of dissolved oxygen 53.4 and 96.7% of air-saturation value at 15.2°C.
The relation between concentration of un-ionized ammonia and period of survival from a few hours to 13 days was investigated for rainbow trout in two tensions of dissolved oxygen, 45.7 and 100.3% of air-saturation value, at 20.1°C.
Period of survival of all the species tested decreased with rise in concentration of un-ionized ammonia.
Decrease in tension of dissolved oxygen increased the toxicity of un-ionized ammonia to all species except gudgeon, for which there was no significant difference in period of survival at the two levels of oxygen.
The effect of oxygen tension on period of survival was greatest in the lowest concentrations of un-ionized ammonia.
Resistance of perch and roach to lack of oxygen was not significantly affected, but that of rainbow trout was reduced significantly, by the presence of a small concentration of ammonia (not toxic to trout within at least 13 days).     

Metabolic responses to acute handling by fingerling inland and anadromous striped bass

Fed and 3-day fasted inland (average mass: 6.97 g) and anadromous (average mass: 6.54 g) striped bass Morone saxatilis fingerlings were held in dipnets above water for 5 min in groups of six. Severity of the response to this handling was measured by whole-body glucose, glycogen, and lactic acid in non-handled bass (considered control level), and then at 30 min, 1, 6, 12, 24 and 48 h recovery. At resting levels, both fed and fasted inland bass showed significantly higher concentrations of the whole body variables than anadromous bass. All four groups of bass showed an increase in lactic acid and glucose immediately after handling, with a concomitant decrease in glycogen. Peak levels of glucose and lactic acid were similar in the four groups. Fasting did not have an effect on the glucose and lactic acid responses, but did affect the glycogen response. The two fasted groups did not return to control glycogen concentrations during the 48-h recovery period. By 48 h, both glucose and lactic acid had returned to control levels. It is concluded that inland and anadromous strains of fingerling striped bass do not differ in their sensitivity to an acute handling stress. Recovery of glycogen energy stores following handling is much better if fish are not fasted before handling.     

氨氮对软体动物生长的影响:以铜锈环棱螺为例

为探究氨氮对底栖动物的毒性效应,在位于湖北保安湖的近自然生态系统(单个水域面积约600 m²,水深约1.5 m)中开展了为期1年的模拟实验,分析了6个不同氨氮浓度[N25>N20>N15>N10>N5>N0(对照);0.2—33.7 mg/L]条件下,大型底栖动物(软体动物)群落特征的差异。结果表明:(1)实验系统中采集的软体动物主要为铜锈环棱螺(Bellamya aeruginosa);(2)从B. aeruginosa密度来看, N0、N5、N10和N15处理相差不大[28(0—85) ind./m²],均显著高于N20和N25处理[5(0—29) ind./m²](P<0.05);(3)从B. aeruginosa生物量来看,N0、N5、N10、N15和N20处理相差不大[40.0(0—85.5) g/m²],均显著高于N25处理[0.8(0—4.0) g/m²](P<0.05);(4)从B. aeruginosa壳长、壳宽和带壳...     

Study on the physiology of diapause, cold hardiness and supercooling point of overwintering pupae of the pistachio fruit hull borer, Arimania comaroffi

The pistachio fruit hull borer, Arimania comaroffi (Ragonot) (Lepidoptera: Pyralidae), is a key pest of pistachio orchards in Iran. This pest passes the winter as diapausing pupae. In this study, some physiological changes in relation to environmental temperature were investigated in field collected pupae. The relationship between supercooling point, cold hardiness and physiological changes of a wild population of this pest was also investigated. The glycogen content decreased with decrease in environmental temperature. Decrease in glycogen content was proportional to increase in total body sugar, trehalose, myo-inositol and sorbitol contents. In January with mean ambient temperature of 5.4°C, glycogen (5 mg/g fresh body weight) content was at the lowest level whereas total body sugar (10.3 mg/g fresh body weight), trehalose (8.6 mg/g fresh body weight), myo-inositol (5.3 mg/g fresh body weight) and sorbitol (2.6 mg/g fresh body weight) were at the highest levels. Total body sugar, trehalose, myo-inositol and sorbitol contents increased as mean temperature decreased from 22.7°C in October to 5.4°C in January. Total body lipid decreased during overwintering and reached to the lowest level at the end of March. Supercooling points were decreased from October to January and reached to the lowest level (-16°C) in January with minimum ambient temperature of -10°C. Survival at low temperature after 24 h was also greatest in January with 72% survival at -10°C, 39% survival at -15°C and 0% survival at -20°C. Increase in temperature from February onward, was proportional with increase in supercooling points and decrease in survival rate. Regardless of sampling date, all pupae died after 24 h at -20°C, whereas none pupae died after 24 h at -5°C. This indicates that this insect is freeze-intolerant.