Bioaccumulation and toxic effects of copper on growth and oxygen consumption by the postlarvae of Penaeus indicus

The aim of this study was to assess the toxic impact of copper on postlarvae (PL) of the penaeid shrimp Penaeus indicus. Tolerance, growth, oxygen consumption and metal accumulation were investigated in these PL on exposure to copper. Tolerance studies were conducted for 96 h to assess the tolerance limits of P. indicus PL exposed to different concentrations of copper using static renewal bioassay tests. Using the Probit method, the regression equation was calculated as Y=0.4899+2.3562 X, with a correlation coefficient of 0.9707. The 96 h LC₅₀ was 0.8204 ppm. The effect of sublethal (one-fifth of 96 h LC₅₀) copper on PL for short- and long-term exposures revealed a significant (p<0.05) decrease in the rate of oxygen consumption, metabolic rate, mean length, wet and dry weight of the exposed PL over their respective controls which can be attributed to a gradual and time-dependent accumulation of the metal, as noticed in the exposed PL through accumulation studies. Overall, the data suggest that on chronic exposure even sublethal concentrations of copper can reduce the metabolic rate and growth in P. indicus PL. This is perhaps the first attempt to use the wild P. indicus PL as a bioindicator of copper toxicity.     

赤潮防治剂对中国对虾的毒性研究

为研究赤潮防治剂对中国对虾的影响,进行了粘土、Ｃａ（ＣＩＯ）２、ＡＩＣＩ３、ＦｅＣＩ３对中国对虾的毒性实验。结果表明：（１）粘土对对虾基本无毒性;（２）Ｃａ（ＣＩＯ）２在低浓度下对对虾无毒,在高浓度下对对虾有急性和慢性毒性;（３）ＡＩＣＩ３和ＦｅＣＩ３在对虾体内有一定的积累,但其毒性效应有待于进一步分析。     

中国对虾两个不同地理种群遗传结构的RAPD分析

采用ＲＡＰＤ技术对中国对虾中国黄渤海沿岸种群（ＨＢ）和朝鲜半岛西海岸种群（ＰＫ）的遗传多样性进行检测。２０个随机引物（ＯＰＤ系列）在二个种群中都扩增出１４８条ＤＮＡ片段，其中多态性片段数分别为５４条和６５条，多态性片段的比例分别为３６．４９％和４３．９２％，种群的平均杂合度分别为０．１９８１和０．２３７５。实验表明，中国对虾朝鲜半岛西海岸种群的遗传多样性要比中国黄渤海沿岸种群高，但二个种群都处于较     

Bioaccumulation and depuration of anthracene in Penaeus monodon (Fibricius) through food ingestion

Understanding on the bioaccumulation and depuration of PAHs (polycyclic aromatic hydrocarbons) in Penaeus monodon is important in seafood safety because it is one of the most popular seafood consumed worldwide. In this study, we used anthracene as the precursor compound for PAHs accumulation and depuration in the shrimp. Commercial feed pellets spiked with anthracene were fed to P. monodon. At 20 mg kg⁻¹ anthracene, P. monodon accumulated 0.1% of the anthracene from the feed. P. monodon deputed the PAH two times faster than its accumulation. The shrimp reduced its feed consumption when anthracene content in the feed exceeded 20 mg kg⁻¹. At 100 mg kg⁻¹ anthracene, P. monodon started to have necrosis tissues on the posterior end of their thorax. The bioaccumulation factor (BAF), uptake rate constant (k₁) and depuration rate constant (k₂) of anthracene in P. monodon were 1.15 × 10⁻³, 6.80 × 10⁻⁴ d⁻¹ and 6.28 × 10⁻¹ d⁻¹, respectively. The depuration rate constant is about thousand times higher than the uptake rate constant and this indicated that this crustacean is efficient in depurating hydrocarbons from their tissue.     

应用斑马鱼和凡纳对虾诊断污染场地污水的生物毒性

应用斑马鱼(Brachydanio rerio)和凡纳对虾(Penaeus vannamei)对某废弃有机污染场地中有毒有机废弃物堆积产生的污水(1号塘污水)和场地及周边地表径流积水(2号塘污水)的生物毒性进行了试验.结果表明,1号塘污水对斑马鱼和凡纳对虾96 hLC50分别为46.2%和59.6%, 2号塘污水的毒性试验中两种试验生物的死亡率皆为0.化学检测表明,1号塘污水中的主要污染物为苯酚类和酞酸脂类物质,而2号塘污水中均未检出有机污染物.化学检测结果与毒性试验结果具有较好的相关性.     

重金属胁迫对日本对虾(Penaeus japonicas )胚胎发育的影响

以受精1 h以内的日本对虾受精卵为实验对象,采用静水试验方法,研究了Zn、Hg、Cu、Pb、As、Cd和Cr 7种重金属对日本对虾胚胎发育的影响。结果表明,在实验浓度范围内,7种重金属中Hg、Cu对日本对虾胚胎发育毒性最大,其次是Zn、As、Cd,Pb和Cr无明显影响。Hg、Cu、Cd、As、Zn对日本对虾胚胎LC₅₀值分别为：0.0177 mg·L^-1、0.1070 mg·L^-1、1.6057 mg·L^-1、3.3682 mg·L^-1、8.2644 mg·L^-1,致死效应最低可观测效用浓度（LOEC）分别为0.0037 mg·L^-1、0.0166 mg·L^-1、0.1302 mg·L^-1、1.1572 mg·L^-1、2.1522 mg·L^-1;抑制发育LOEC分别为0.0062 mg·L^-1、0.0176 mg·L^-1、0.4002 mg·L^-1、1.9497 mg·L^-1、0.0617 mg·L^-1。随着Hg、Cu浓度的升高,胚胎孵化率不断下降,无节幼体死亡率不断上升,在Hg 0.0256 mg·L^-1浓度组中,胚胎48 h死亡率达到100%。以上结果说明,Hg、Cu等重金属的存在会延缓日本对虾胚胎的发育速度,随着重金属浓度的增加,滞育现象愈加明显,在Cu 0.32 mg·L^-1浓度组中,未见无节幼体孵出。     

中国对虾血细胞包掩作用的超微结构和组织化学观察

用鳗弧菌注射中国对虾,对其体内血细胞的包掩作用进行了超微结构和组织化学观察．结果表明：在注菌的对虾体内,包囊产生于多种器官和组织,在释放颗粒的过程中,半颗粒细胞和颗粒细胞的表面即发生变化,开始与周围细胞相粘接;在包囊中心是电子不透明的非结构团块;含吞噬泡的透明细胞也常被包围在包囊内,构成包囊的血细胞中细胞器趋于退化,在组织化学上表现为细胞中的ＲＮＡ大为减少,色氨酸几乎消失;然而,包囊从开始形成起,就呈Ｃｈｅｖｒｅｍｅｎｔ铁氰化钾法强阳性反应,此反应可被Ｂａｒｎｅｔ碘液法封闭．推测这一现象与黑色素生成有关．     

Effect of Water Variables On Lead Tolerance in Postlarvae of Penaeus Indicus (H. Milne Edwards)

Lead tolerance in Penaeus indicus post-larvae (PL) was studied in relation to the water variables: salinity, temperature and pH. the LC₅₀ for 96 hrs was 7.22 ppm at ambient conditions of salinity (20%_o), temperature (29°C) and pH (7.2). the post-larvae were found to be sensitive to salinity variations with a significant (P < 0.05) low LC₅₀ values at lower (2%_o) and higher (29%_o) ranges. Though a decrease in LC₅₀ value was observed both at higher (45°C) and lower (10°C) temperatures, it was significantly (P < 0.05) low only at higher temperature indicating more toxicity. the LC₅₀ values also showed a significant (P < 0.05) decrease in acidic (pH 2.8) and alkaline (pH 11.0) conditions. the data indicate that lead toxicity increases in the PL of P. indicus with variations in the water variables.     

Acute and chronic toxic effect of lead (Pb) and zinc (Zn) on biomarker response in post larvae of Penaeus monodon (Fabricus, 1798)

Metal pollution produces damage to marine organisms at the cellular level possibly leading to ecological imbalance. The present investigation focused on the acute and chronic toxicity of lead (Pb) and zinc (Zn) by examining the effects of biomarker enzymes in post-larvae of Penaeus monodon (Tiger prawn). Antioxidant biomarker responses such as lipid peroxidation (LPO) and catalase (CAT) activity for Pb and Zn were determined following chronic exposure. Acute Lethal Concentration ₅₀ (LC₅₀) values observed in the study at 96?h for Pb and Zn at 5.77?±?0.32?mg?L^?1 and 3.02?±?0.82?mg?L^?1, respectively. The estimated No Observed Effect Concentration and Lowest Observed Effect Concentration values for Pb were 0.014 and 0.029?mg?L^?1 and that recorded for Zn was 0.011 and 0.022?mg?L^?1, respectively. Among the two metals studied, toxicity of Zn was found to be greater to P. monodon than Pb. The activities of antioxidant defense enzymes and total protein content differed significantly from control following exposure to both metals. Overall, the biomarker studies demonstrated that alterations in antioxidant enzymes and induction of LPO reflect the consequences of heavy metal exposure in P. monodon.     

盐度变化对日本对虾暴发白斑综合症病毒病的影响

为研究盐度在对虾暴发白斑综合症 (whitespotsyndrome)过程中所起的作用 ,进行了盐度变化对日本对虾免疫水平的影响实验及不同盐度下的人工感染实验。结果显示 :(1)盐度是影响日本对虾生理、存活的重要环境因子 ;(2 )盐度变化能够影响对虾的免疫状况 ,盐度升高和降低都会降低日本对虾的免疫水平 ;(3)在偏离对虾正常生存盐度的环境中 ,对虾抵御外来感染能力降低 ,易受病原体如WSSV的感染 ;(4)盐度变化是导致对虾爆发白斑综合症的重要诱因之一。