斑石鲷低氧耐受能力及血液生理生化指标变化研究

为阐明斑石鲷(Oplegnathus punctatus)低氧耐受能力及低氧胁迫过程中血液生理生化指标的变化规律，本研究通过生理学和生态学方法，查明2种规格斑石鲷在临界氧分压(critical oxygen tension, Pcrit)和失去平衡点(loss equilibrium, LOE)时的溶解氧浓度，观察自然耗氧条件下其呼吸行为变化，分析低氧胁迫和恢复溶解氧过程中血液皮质醇和葡萄糖含量、血红蛋白(hemoglobin, Hb)浓度、红细胞(red blood cell, RBC)和白细胞(white blood cell, WBC)数目、红细胞积压(hematocrit, HCT)变化。结果显示，在水温(23.0±0.5)℃、氨氮浓度<0.5 mg/L、亚硝酸盐浓度0~0.05 mg/L、盐度为30、pH为7.80的条件下，200和50 g斑石鲷的Pcrit值分别为(4.05±0.09)和(3.15±0.12) mg/L，LOE值分别为(1.16±0.08)和(0.93±0.11) mg/L，且50 g斑石鲷到达LOE值的时间(t=480 min)比200 g斑石鲷(t=110 min)更长；自然耗氧过程中，2种规格斑石鲷呼吸频率均呈先升高后降低的变化趋势，且均在Pcrit值处显著升高，达到最大值(P<0.05)。低氧胁迫导致血浆葡萄糖和皮质醇含量显著升高，在LOE值处达到最大值(P<0.05)，但50 g斑石鲷的葡萄糖和皮质醇含量上升幅度显著低于200 g斑石鲷(P<0.05)。同时，低氧引起斑石鲷的WBC和RBC数目、Hb浓度和HCT显著升高，50和200 g斑石鲷分别在Pcrit和LOE值处达到最大值(P<0.05)。恢复正常溶解氧24 h后，2种规格斑石鲷均恢复正常呼吸运动，上述生理生化指标均与对照组无显著差异(P>0.05)。综上所述，2种规格的斑石鲷相比较，50 g斑石鲷的低氧耐受能力更强，200 g斑石鲷对低氧胁迫的应激反应更敏感，2种规格斑石鲷均可通过增加呼吸频率、提高血液WBC和RBC数、皮质醇、葡萄糖和Hb浓度，增强对溶解氧的吸收利用，应对低氧胁迫导致的生理状态改变，相关结果为斑石鲷高效养殖提供了基础数据。     

低氧胁迫对鲢抗氧化酶活性及SODs基因表达的影响

为研究低氧胁迫对鲢(Hypophthalmichthys molitrix)不同组织抗氧化酶活力及对相关基因的影响,将体重(200±12.4) g的鲢放置于密闭水箱中,通过鱼体自发耗氧进行低氧处理,在常氧[溶氧为(6.42±0.3) mg/L]、浮头[溶氧为(0.76±0.03) mg/L]、半窒息[溶氧为(0.58±0.06) mg/L]和窒息[溶氧为(0.27±0.06) mg/L]时分析血液、鳃和肝脏组织中的抗氧化酶活性及超氧化物歧化酶基因(SODs)表达特征。结果显示:低氧胁迫过程中,血清过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GPX)活力逐渐增加,CAT活力在半窒息时显著升高,GPX无显著变化,超氧化物歧化酶(SOD)活力相比其他组均显著降低;肝脏中SOD、CAT酶活力呈先升高后下降的趋势,在窒息组时酶活力显著降低,GPX无明显变化。肝脏中Cu/Zn-SOD mRNA表达量在浮头和窒息时相比于常氧组有显著差异,鳃中Cu/Zn-SOD表达量在低氧胁迫组均显著低于常氧组;Mn-SOD基因在肝脏中的相对表达量先升高后下降,在半窒息时显著降低;鳃中Mn-SOD在浮头时的表达量显著降低后趋于平稳。鲢对低氧胁迫产生氧化应激,但其可以通过自身的抗氧化系统进行调节,而当溶解氧过低时机体出现损伤,甚至死亡。     

低氧对鲂鲌杂交种F3鳃结构及生理生化的影响

向常氧[溶解氧质量浓度(7.19±0.23) mg/L]水中充入氮气或空气对鲂鲌杂交种(团头鲂♀×翘嘴鲌♂)F₃进行低氧[溶解氧质量浓度(1.04±0.12) mg/L]及复氧[溶解氧质量浓度(7.16±0.20) mg/L]处理，取常氧、低氧12 h、低氧24 h、低氧72 h及复氧24 h的鲂鲌杂交种F₃鳃组织，并利用苏木精-伊红染色、阿利新蓝-过碘酸染色、抗氧化酶活性测定、荧光定量PCR等技术，探究鲂鲌杂交种F₃鳃组织对低氧的适应性。试验结果显示：低氧处理72 h后，鲂鲌杂交种F₃的鳃组织层间细胞团宽度和鳃小片长度分别为(42.42±4.76)μm、(109.09±8.96)μm,鳃组织与水的接触面积较常氧显著增加；低氧胁迫显著降低了鲂鲌杂交种F₃鳃组织黏液细胞的密度，鳃组织分泌黏液减少；低氧胁迫下，鲂鲌杂交种F₃鳃组织的超氧化物歧化酶活性、丙二醛含量在处理72 h时最大，过氧化氢酶的活性在处理24 h时活性最大；低氧胁迫显著改变了鳃组织中caspa...     

低氧胁迫对西伯利亚鲟幼鱼生理状态的影响

为探究低氧胁迫对西伯利亚鲟幼鱼的血液基础指标、抗氧化和能量代谢相关酶活力的影响,以体质量为(19.46±4.9)g的西伯利亚鲟幼鱼为研究对象,开展了低氧(2.3mg/L)胁迫3h和自高氧(18.5mg/L)逐渐降至低氧(2.8mg/L)又恢复到正常溶氧(7mg/L),这两种不同情况下的低氧胁迫试验。检测了血液红细胞数、血红蛋白质量浓度,以及肝脏和肌肉的抗氧化酶活力和鳃组织三磷酸腺苷酶活力。结果显示,低氧胁迫下西伯利亚鲟幼鱼血红细胞数升高,血红蛋白质量浓度、血液pH、肝脏和肌肉的超氧化物歧化酶和过氧化氢酶活力以及碱性磷酸酶活力均低于正常溶氧组,而鳃组织钠/钾—三磷酸腺苷酶活力无明显变化。试验结果显示,急性低氧胁迫能较快使西伯利亚鲟幼鱼血液红细胞数目增加,并影响肝脏、肌肉的抗氧化应激及代谢相关酶活力,但是短时间内西伯利亚鲟幼鱼可能还未实现鳃部的能量调节。     

低氧胁迫和恢复对长吻鮠脑组织低氧应答基因、生理生化指标和食欲的影响

为了解长吻鮠脑组织应对低氧胁迫的调控机制，实验运用酶活性测定、H.E染色、qRT-PCR和TUNEL检测等方法，分析比较了低氧胁迫[(0.8±0.1) mg/L] 0、2、4、6 h(标示为H0、H2、H4和H6)和恢复[(7.3±0.5) mg/L]2、4、6 h (标示为R2、R4和R6)下长吻鮠脑组织低氧应答基因、生理生化指标和食欲基因的变化。结果显示，在低氧胁迫和恢复下，长吻鮠脑组织氧传感蛋白相关基因(HIFs、PHDs和Vhl)表达量整体呈现出先上升后下降趋势；呼吸代谢酶(HK、PK和LDH)活性在H0时显著升高，SDH和MDH活性在H6时显著降低，恢复溶解氧后，代谢模式由无氧呼吸逐渐转变为有氧呼吸；抗氧化酶(GSH-Px、CAT和SOD)和应激指标(MDA和LPO)在低氧2 h后逐渐升高，恢复溶解氧后氧化应激现象仍然存在。观察脑组织形态发现，在低氧胁迫下长吻鮠脑组织出现了神经细胞肿胀、空泡等受损现象，恢复溶解氧6 h后脑组织受损并未得到有效改善。随着低氧时间延长，脑组织细胞凋亡程度不断增加，凋亡相关基因(Bax、Caspase-3和p53)表达量显著升高，而Bcl-2基因表...     

急性低氧胁迫对青海湖裸鲤血液指标和肝脏氧化应激及糖代谢的影响

为探究青海湖裸鲤(Gymnocypris przewalskii)血液和肝脏组织对急性低氧胁迫的生理响应,将体质量(25.3±3.4)g的1龄青海湖裸鲤放在透明密封的(长33 cm×宽22 cm×高18 cm)水槽中,每槽22尾。急性低氧处理前,水槽持续充氧,水体溶解氧浓度为(8.1±0.2)mg·L^-1(对照组)。急性低氧胁迫时,终止充氧,用透明塑料薄膜覆盖水槽上方,水槽内水体溶解氧浓度快速下降(试验组)。当半数青海湖裸鲤出现如行动迟缓、反应迟钝、身体失衡等缺氧症状时[约(43±2)min,溶解氧约为(0.46±0.03)mg·L^-1],测定水体溶解氧浓度,同时取样测定青海湖裸鲤血液生理生化指标和肝脏抗氧化及糖代谢相关指标的变化。结果表明,在急性低氧胁迫后,青海湖裸鲤血液生理生化指标均呈现出不同程度的变化趋势。其中Na⁺、K⁺、Mg²⁺、Cl^-和尿素氮(BUN)浓度与胁迫前相比无显著差异(P>0.05),Ca²⁺浓度显著高于胁...     

温度和溶解氧对仿刺参存活、代谢及运动能力的影响

为探究温度和溶解氧(DO)对仿刺参存活、代谢及运动能力的影响,采用实验生态学方法,测定了水温为15°C、DO浓度为(1.0±0.1)mg/L低氧胁迫条件下大规格仿刺参[(39.35±0.40)g]单位时间内的移动距离和体表面积的变化;测算了水温15°C(适宜温度)、20°C和25°C条件下,2种规格[大(32.70±4.46)g、小(10.31±2.03)g]仿刺参在(1.0±0.1)mg/L低氧胁迫下的半致死时间(LT50),比较分析了3个温度水平(15、20及25°C)和3个DO水平[(1.0±0.1)、(3.0±0.1)及6.5 mg/L(正常DO含量)]交互作用下2种规格仿刺参的呼吸代谢强度。结果显示,水温15°C、(1.0±0.1)mg/L低氧胁迫下,随胁迫时间的增加,仿刺参运动速度总体呈现降低趋势,至胁迫72 h全部死亡;体表面积呈先增大后减小的趋势,整个胁迫期间,身体均处于伸长状态,至死亡仍显著高于对照组。(1.0±0.1)mg/L低氧胁迫时,水温15°C条件下大规格仿刺参半致死时间(LT50)为54.0 h,小规格为44.7 h;水温20°C条件下大规格仿刺参LT50为48.9 h,小规格为39.3 h;水温25°C条件下大规格仿刺参LT50为33.4 h,小规格为28.9 h。15°C组大小2种规格仿刺参的半致死时间均高于对应的20°C和25°C组,且大规格个体的低氧耐受能力高于小规格个体。相对于20°C和25°C组,在3个DO水平下,15°C组2种规格仿刺参的呼吸代谢均最为活跃,但与15°C常氧组相比,(1.0±0.1)mg/L低氧胁迫时仿刺参的呼吸代谢强度均受到明显抑制。研究表明,低氧胁迫下,仿刺参可能会通过拉长身体增加体表面积来增加氧气摄入量,并以减少运动、降低代谢强度等策略来应对低氧环境,延长存活时间。     

氨氮胁迫对不同规格刺参(Apostichopus japonicus)存活及非特异性免疫酶活性的影响

本实验以小[(6.05±0.44)g/头]、中[(14.68±1.76)g/头]、大[(25.64±3.27)g/头]的3种不同规格刺参(Apostichopus japonicus)为研究对象,研究了氨氮胁迫浓度为0、2、4、6、8、10 mg/L时对刺参体腔液中溶菌酶(LSZ)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性的影响。结果显示,在氨氮浓度为8 mg/L时,第10天后,3种不同规格刺参均出现吐肠、化皮,直至死亡。氨氮浓度为10 mg/L时中规格刺参存活率最低,为86.7%。在氨氮浓度为2 mg/L和4 mg/L时,小、中、大规格刺参的3种非特异性免疫酶活性在第4天显著升高,与对照组(氨氮浓度低于0.05 mg/L)差异显著(P0.05);第7、10、13天时,LSZ、CAT、SOD酶活性与第4天相比,差异不显著(P0.05)。在氨氮浓度为6、8、10 mg/L时,LSZ、CAT、SOD酶活性在第7天达到最高,与对照组差异性显著(P0.05)。氨氮胁迫对3种不同规格刺参的非特异性免疫酶活性的影响存在差异,在同一氨氮浓度胁迫下,敏感性依次为中规格大规格小规格。研究表明,氨氮胁迫会对刺参存活与免疫产生一定影响,在刺参养殖过程中,水环境中氨氮浓度最好控制在6 mg/L以内。     

低氧胁迫对鲻幼鱼生长、能量代谢和氧化应激的影响

为研究低氧胁迫对鲻幼鱼生长、能量代谢和氧化应激的影响,实验将其放在溶解氧(DO,mean±SE)含量分别控制在(1.66±0.41)、(4.35±0.53)、(7.03±0.36)mg/L的条件下养殖10 d,然后恢复至接近饱和溶解氧含量7.0 mg/L的条件下养殖30 d,研究其特定生长率、排氨率、耗氧率、氧氮比和血浆、肌肉、肝脏及鳃组织的总抗氧化能力(T-AOC)、过氧化物歧化酶(SOD)活力、抗超氧阴离子活力(ASOR)、丙二醛(MDA)含量、乳酸(LD)含量、总谷胱甘肽(T-GSH)、还原型谷胱甘肽(GSH)和氧化型谷胱甘肽(GSSG)含量。结果表明:低氧胁迫对鲻幼鱼的生长、能量代谢影响显著,较严重缺氧组鲻的体质量、特定生长率(SGR)、耗氧率和排氨率显著低于其他处理,不具有补偿生长的能力;而轻微缺氧组获得完全补偿生长。低氧胁迫对鲻氧化应激指标影响显著,胁迫结束时鲻通过提高某些抗氧化酶的活力来增强抗氧化能力,以提高其应对恢复正常溶解氧环境可能带来的氧化应激的能力,同时在恢复溶氧后鲻氧化应激反应也较强烈。在恢复溶解氧阶段,肝脏中GSH显著增加,说明鲻体内的保护机制被激活。肝脏和鳃中MDA的含量在低氧胁迫后与溶解氧含量呈明显的负相关性,在复氧30 d后仍然高于对照组,表明低氧胁迫加强鲻肝脏和鳃组织脂质过氧化反应。     

氨氮胁迫对锦绣龙虾代谢酶和抗氧化酶活力的影响

为了研究急性氨氮胁迫对锦绣龙虾(Panulirus ornatus)抗氧化系统及氨氮代谢机制的影响,通过设置对照[(0.24±0.07)mg/L]、低浓度[(1.04±0.08)mg/L]、中浓度[(9.75±0.21)mg/L]和高浓度[(19.87±0.46)mg/L]氨氮胁迫方法对锦绣龙虾进行48 h急性实验,测...     

Anguilla huangi Teng, Lin, and Tzeng, 2009, is a junior synonym of Anguilla luzonensis Watanabe, Aoyama, and Tsukamoto, 2009

Anguilla luzonensis and A. huangi were each described in 2009 using eels obtained from northern Luzon Island. We examined the taxonomic status of these two groups of eels using morphological and molecular genetic characters. There were no significant differences in two vertebrae counts between eels of A. luzonensis and A. huangi. Mitochondrial 16S ribosomal RNA and cytochrome b genes sequences were obtained and compared among 28 specimens of A. luzonensis, the holotypes of A. luzonensis and A. huangi, and one specimen of the other 15 anguillid species. The specimens of A. luzonensis exhibited almost identical sequences, including the holotype, with only a few site differences, and the genetic difference between the holotypes of A. luzonensis and A. huangi was within the range of differences of specimens of A. luzonensis. The other anguillid species were genetically very different from A. luzonensis and A. huangi, although A. interioris is a closely related species. It is clear that A. luzonensis and A. huangi are the same species, and according to the principle of priority in zoological nomenclature, A. luzonensis Watanabe, Aoyama, and Tsukamoto, 2009 is the valid species name, and A. huangi Teng, Lin, and Tzeng, 2009 is a junior synonym of A. luzonensis.     

Atlantic Fisheries Technological Conference,Moncton, NB,August 21, 1995

No abstract available for this article.     

Effects of Mosquitofish,Gambusia affinis,on Channel Catfish,Ictalurus puncatatus,Production Ponds

Mosquitofish, Gambusia sp., have been spread throughout the world to biologically control mosquitoes. However, the fish has gained a reputation as an invasive species and has been implicated in displacing native aquatic species. Gambusia affinis are native to the southeastern United States and commonly occur in commercial channel catfish, Ictalurus punctatus, production ponds. We investigated effects of mosquitofish presence on zooplankton populations, water quality, disease occurrence, and fish production in experimental ponds. There were no differences between ponds with or without mosquitofish in numbers of calanoid copepods, cyclopoid copepods, total copepods, Bosmina sp., Ceriodaphnia sp., Moina sp., Daphnia sp., or total cladocerans. There were also no differences in copepod and cladoceran sizes. Copepod nauplii were more numerous during the summer months in ponds with mosquitofish. There were no differences in water quality variables (soluble reactive phosphorus, nitrate, nitrite, ammonia, total nitrogen, total phosphorus, pH) or phytoplankton density between ponds stocked with and without mosquitofish. Catfish production and disease occurrence were also similar between ponds with and without mosquitofish. Although mosquitofish may cause problems when stocked outside their native range, there does not appear to be any adverse effects of mosquitofish presence in catfish production ponds.     

Age,growth, maturity and the overfishing of the iconic sciaenid,Argyrosomus japonicus,in south-eastern,Australia

Mulloway (Argyrosomus japonicus) occur in estuarine and coastal waters surrounding Australia, Africa, India, Pakistan, China, Korea and Japan, where they are important in fisheries. This study identified that mulloway in south-eastern Australia had similar growth rates, but matured at smaller lengths and younger ages, to those in South Africa and Western Australia. Growth of both sexes was similar to about 5 years, after which females grew faster and attained a greater maximum length than males. Female mulloway matured at 4–5 years of age with a L₅₀ of 68 cm, whereas males matured at 2–3 years of age with a L₅₀ of 51 cm. The commercial fishery in New South Wales was characterised by declining catches and a reduction in the proportion of mulloway of mature lengths in landings. During 2002–2005 commercial landings were dominated (83%) by fish within 15 cm of the current minimum legal total length of 45 cm and aged 2 and 3 years (>80%), even though mulloway can attain lengths of 200 cm and live >30 years. Estimates of the rates of instantaneous total mortality ranged between 0.34 and 0.45, whilst the rate of instantaneous natural mortality (M) was estimated to be approximately 0.12. Yield-per-recruit analyses indicated that mulloway in New South Wales are being growth overfished and substantial increases in yield could be achieved by increasing the length at first harvest. Values of the spawning potential ratio were below 0.2 under a range of mortality estimates, suggesting that mulloway are at risk of recruitment overfishing. These results suggest that the spawning stock of mulloway in south-eastern Australia has been depleted and that remedial management action is required to protect this iconic species.     

Compositional differences,antioxidant activity,angiotensin-converting enzyme inhibition,and sensory characteristics of kamaboko fermented in wheat,rice, brown rice,and soybean koji

Fisheries Science - Fermentation of kamaboko in koji with wheat (KW), rice (KR), brown rice (KB), or soybean (KS) was performed by simulation of tofuyo processing. Moisture and protein content...     

Sperm Motilities in Waigieu Seaperch,Psammoperca waigiensis: Effects of Various Dilutions,pH, Temperature,Osmolality, and Cations

The objectives of this study were to evaluate the effects of varying dilutions, pH, temperature, osmolality, and cations on sperm motility parameters in waigieu seaperch, Psammoperca waigiensis. The maximum velocity of average in path (VAP), percentage of motile cells (MOT), and duration of sperm motility (DSM) were observed when semen was diluted in artificial seawater (ASW) at a ratio of 1:100 (144.9 ± 0.6 µm/sec, 95.6 ± 0.4%, and 230.3 ± 2.3 sec, respectively), at 30 C (142.0 ± 0.6 µm/sec, 93.6 ± 0.4%, and 238.3 ± 0.9 sec, respectively), and pH 8 (144.8 ± 0.6 µm/sec, 93.3 ± 0.4%, and 234.0 ± 1.5 sec, respectively). Maximum VAP, MOT, and DSM were obtained in each solution containing 0.6 M NaCl (143.8 ± 1.0 µm/sec, 91.3 ± 2.0%, and 230.6 ± 4.2 sec, respectively), 0.6 M KCl (135.1 ± 3.1 µm/sec, 91.1 ± 3.1%, and 230.3 ± 3.7sec, respectively), 0.2M CaCl₂ (105.3 ± 4.7μm/sec, 47.9 ± 2.7%, and 120.7 ± 1.3 sec, respectively), 0.2 M MgCl₂ (107.3 ± 3.0 m/s, 42.1 ± 3.3%, and 120.3 ± 4.8 sec, respectively), and osmolality of 400 mOsm/kg (145.1 ± 2.5 µm/sec, 93.0 ± 2.1%, and 346.5 ± 4.4s, respectively). We used these mediums as artificial insemination media for fertilizing matured eggs. The results showed that the fertilization and hatching rates in 0.6 M NaCl (75.3 ± 0.6% and 57.0 ± 2.4%, respectively), ASW (70.8 ± 1.2% and 51.2 ± 1.8%, respectively), or 400 mOsm/kg (72.9 ± 1.8% and 55.3 ± 1.6%, respectively) were higher than that in seawater (63.9 ± 1.2% and 39.2 ± 3.9%, respectively). In conclusion, using 0.6 M NaCl, ASW, or 400 mOsm/kg as an artificial insemination medium is effective for fertilizing of waigieu seaperch.     

Surface disinfection of Pacific threadfin, Polydactylus sexfilis, and amberjack, Seriola rivoliana, eggs

The effects of exposing the eggs of Pacific threadfin and amberjack eggs (AEs) to different concentrations of hydrogen peroxide for 5 min on hatch rate and survival were assessed in a series of experiments using a petri dish model rearing system. Despite significant inter‐batch variation in hatch rate, it was shown that eggs of both species could be safely exposed to up to 11 340 mg L⁻¹ H₂O₂ for 5 min. Exposure to 34 230 mg L⁻¹ H₂O₂ for 5 min was shown to be lethal to AEs at a late stage of development. In two further experiments, it was demonstrated that Pacific threadfin eggs were resistant to all tested concentrations of a range of polyvinylpyrrolidone iodine (PVP‐I) concentrations and contact times (up to 1000 mg L⁻¹ PVP‐I for 10 min). The level of bacteria adhering to the eggs of both species was highly variable. Where eggs were heavily colonized (>10⁴ cfu egg⁻¹), hydrogen peroxide concentrations of at least 11 340 mg L⁻¹, or PVP‐I concentrations higher than 500 mg L⁻¹ for 10 min, were required for effective sterilization. In less colonized batches, rinsing in sterile seawater or exposure to lower (550 mg L⁻¹) concentrations of H₂O₂ was sufficient to result in high apparent levels of surface sterility (<1 cfu egg⁻¹).     

Operating parameters affecting biofloc technology: carbon source,carbon/nitrogen ratio,feeding regime,stocking density,salinity, aeration,and microbial community manipulation

Aquaculture International - The world population continues to increase day by day. Therefore, aquaculture needs to grow in order to response the need for protein foods and to cope with the problem...