Effects of Sublethal Copper Concentrations on Gills of White Shrimp (Litopenaeus vannamei, Boone 1931)

The objective of this study was to measure the copper (Cu) concentration in gills of juveniles Litopenaeus vannamei after exposure to Cu at sublethal concentrations, and to evaluate its effect upon the structure of gill tissue. The Cu concentration in gills of control shrimp was 0.075 mg/kg. Copper concentrations increased significantly by 147 %, 180 % and 205 % in gills of shrimp exposed to 0.675, 1.325 and 2.010 mg Cu/L, respectively. After exposure to 0.675 mg Cu/L for 15 days, gill tissue hyperplasia was observed, with a narrowing of the hemolymphatic lacunae. Necrosis and loss of hemolymphatic lacunae were observed at exposures of 1.325 and 2.010 mg Cu/L.     

Experimental Induction of Morphological Deformities in Chironomus riparius Larvae by Chronic Exposure to Copper and Lead

Five consecutive generations of Chironomus riparius Meigen larvae were chronically exposed from egg to fourth instar to four sublethal concentrations of copper (0, 1, 10, 100 μg L⁻¹) and lead (0, 5, 50, 500 μg L⁻¹) in artificially spiked water (static with renewal), with diatomaceous earth as substrate and tetraphyl? as food, in order to test the induction of morphological deformities by these metals. The use of diatomaceous earth was suboptimal because it caused high mortalities (>60%), independent of metal stress. The higher copper concentrations had a positive effect on the survivals relative to the control. Split medial mentum teeth were recorded in more than 10% of the larvae, but could not be related to metal stress. Deformities of the mentum and the mandibles were recorded in second, third, and fourth instars exposed to both metals. Concentration and generation effects were noted for unusual number of mentum teeth (0–5.3%, lead), unusual number of mandible inner teeth (0–10.4%, copper and lead), and small open mentum gap (0–6.5%, copper). These experiments demonstrated the potential of both an essential and a non-essential metal to induce weak deformities in a small proportion of a C. riparius population as well as the induction of deformities which are independent of metal stress or fluctuating over the generations. The study shows the potential of midge deformities as a biomonitoring tool, but at the same time warns for a careful interpretation of deformity scores because of the influence of population dynamics on the final outcome of deformity frequencies and of the existence of deformities not related to pollution. Received: 25 August 1997/Accepted: 17 January 1998     

Histopathological Alterations in Gills of White Shrimp, <Emphasis Type="Italic">Litopenaeus vannamei</Emphasis> (Boone) After Acute Exposure to Cadmium and Zinc

White shrimp, Litopenaeus vannamei, a globally important cultured prawn species, is an ideal animal for studying the impairment caused by the effects of heavy metals that are often detected in coastal areas. In this present study, we detected the acute toxicity of cadmium (Cd) and zinc (Zn) to L. vannamei. Medium lethal time (LT50) values of Cd and Zn on L. vannamei were estimated. Furthermore, we also demonstrated that acute exposure to high concentrations of Cd and Zn resulted in morphological alterations in gills of L. vannamei in this present study.     

Virulence factor genes and comparative pathogenicity study of tdh,trh and tlh positive Vibrio parahaemolyticus strains isolated from Whiteleg shrimp,Litopenaeus vannamei (Boone, 1931) in India

Vibrio parahaemolyticus is a gram-negative halophilic bacterium responsible for gastrointestinal infection in human and vibriosis in aquatic animals. The thermostable direct hemolysin (tdh), tdh-related hemolysin (trh) and thermolabile hemolysin (tlh) positive strains of V. parahaemolyticus were identified from brackishwater aquaculture farms of West Bengal and Andhra Pradesh, India. Moreover, the presence of other virulent genes like vcrD1, vopD, vp1680 under type three secretion system 1 (T3SS1) and vcrD2 vopD2, vopB2, vopC2 under type three secretion system 2 (T3SS2) were detected in tdh positive strain of V. parahaemolyticus. Furthermore, the study revealed that the tdh and trh positive isolates were resistant to β-lactam antibiotics and were able to lyse more than 95% of human Red Blood Cells (RBCs). In addition, both the isolates showed high cytotoxicity in Human Embryonic Kidney (HEK) cell line compared to tlh positive strain. Additionally, intraperitoneal and oral administration of tdh and trh positive strain of V. parahaemolyticus in Indian Major Carp, Labeo rohita caused 100% mortality at the level of 2.0 × 10⁸ CFU ml⁻¹ and 1.6 × 10⁸ CFU ml⁻¹, respectively. In contrast, only 10% mortality was observed in the case of tlh positive strain at the level of 2.5× 10⁸ CFU ml⁻¹. The histopathological changes like infiltration of blood cells and degenerated hepatic tissue in the liver of L. rohita were observed after the experimental challenge. The changes like degeneration of glomeruli, necrosis of renal tubules and Bowman's capsule were observed in the kidney section. Ragged, irregular shaped villi and necrosis of the villus were observed in the intestinal lumen. Overall, the study demonstrates that isolated V. parahaemolyticus is a potent aquatic microbial pathogen. Additionally, as V. parahaemolyticus is also a human pathogen and might pose a threat to the human population, proper management strategies are required to prevent the possible occurrence of disease.     

Behavioral Alterations in Juvenile Cyprinus carpio (Linnaeus, 1758) Exposed to Sublethal Waterborne Cadmium

No abstract available.     

Evaluation of the Bioaccumulation of Heavy Metals in White Shrimp (Litopenaeus vannamei) Along the Persian Gulf Coast

The concentrations of heavy metals in Persian Gulf are low, but petrochemical and refinery activities have caused an increase in heavy metal wastes, especially in coastal regions. The present study was done to determine the bioaccumulation of heavy metals in the muscle of white shrimp (Litopenaeus vannamei) using flame atomic absorption spectrophotometry. The experiment was conducted in four important coastal regions of the Persian Gulf: Bushehr, Deylam, Mahshahr, and Abadan. Amounts of seven heavy metals such as Copper (Cu), Iron (Fe), Lead (Pb), Zinc (Zn), Nickel (Ni), Cadmium (Cd), and Cobalt (Co), were measured as µg/g heavy metal in dry weight in the muscle of white shrimp from the afore-mentioned regions during 2011. This study revealed information that the primary risk for human health and the marine life chain was lead in the muscles of white shrimp in Mahshahr, where intense petrochemical and refinery activities are conducted. Concentrations of other heavy metals were lower than world standards.     

Evaluation of sublethal biomarkers in Litopenaeus vannamei on foodborne exposure to methyl parathion

Sublethal effects of foodborne exposure to methyl parathion (0.62 and 1.31 microg methyl parathion*g(-1) dry weight of food) on juveniles of Litopenaeus vannamei using integrated biochemical (acetylcholinesterase (AChE) and ATPases) and physiological (feeding rate (FR), egestion rate (ER), and hepatosomatic index (HI)) biomarkers were evaluated. The HI was significantly higher in controls than in pesticide treatments. The FR was significantly lower in controls than in pesticide treatments while no significant differences were detected in the ER. AChE activity was significantly higher in controls than in pesticide treatments (control = 0.11 +/- 0.02; solvent control = 0.11 +/- 0.03; 0.62 = 0.07 +/- 0.01; 1.31 = 0.08 +/- 0.02 microM*min(-1)*mgprotein(-1)). The total-ATPase activity was significantly lower in controls than in pesticide treatments (control=77.90+/-12.41; solvent control = 83.69 +/- 22.05; 0.62 = 110.03 +/- 22.17; 1.31 = 121.54 +/- 19.84 microM P(i)*h(-1)*mgprotein(-1)). The Mg(2+)-ATPase activity was significantly higher in treatments than in controls (control = 65.14+/-10.76; solvent control = 75.12 +/- 21.10; 0.62 = 100.53 +/- 20.97; 1.31 = 108.94 +/- 17.26 microM P(i)*h(-1)*mgprotein(-1)). Finally, the results obtained for the Na(+)/K(+)-ATPase activity were significantly higher in control and in 1.31 than in solvent control and in 0.62 (control = 14.06+/-2.63; solvent control=7.30 +/- 4.13; 0.62 = 7.60 +/- 3.81; 1.31 = 13.42 +/- 2.88 microM P(i)*h(-1)*mgprotein(-1)). The results in this study showed that pulse exposures to methyl parathion via food could elicit measurable effects on the marine shrimp L. vannamei, indicating that foodborne exposure can be a reliable toxicological procedure and, if combined with pulse exposures, could also simulate more realistic exposure scenarios.     

Effects of methamidophos on acetylcholinesterase activity, behavior, and feeding rate of the white shrimp (Litopenaeus vannamei)

The toxicity of methamidophos on the shrimp Litopenaeus vannamei was evaluated using acetylcholinesterase (AChE) activity, behavior, and feeding rate as effect criteria. The biochemical characterization of the soluble cholunesterase (ChE) present in both muscle and eye tissues of L. vannamei was performed in a first phase of the study. In both tissues, almost full inhibition of enzyme activity by eserine sulfate was found, indicating that the measured activity is mainly from ChE and not from other esterases. The highest rate of substrate hydrolysis was found when acetylthiocholine was used as substrate. To evaluate the effects of methamidophos on L. vannamei AChE, behavior, and feeding rate, shrimps were exposed for 24h to several sublethal concentrations of methamidophos. Significant effects of the pesticide on behavior and AChE were found, with behavior being a more sensitive endpoint than AChE inhibition. Feeding rate was not a sensible endpoint under conditions tested.     

Effects of sodium carbonate and sodium bicarbonate on yield and characteristics of Pacific white shrimp (Litopenaeus vannamei)

Effects of sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) on yield and characteristics of Pacific white shrimp (Litopenaeus vannamei) were studied. Shrimp soaked in 2.5% NaCl containing both compounds at different levels of pH (5.5, 7, 8.5, 10 and 11.5) showed an increase in the weight gain and cooking yield and a reduced cooking loss as pH of solutions increased (p<0.05). Increases in pH and salt content in soaked shrimp muscle were obtained with increasing pH (p<0.05). Higher pH of soaking solution partially solubilized proteins in the muscle as well as carotenoproteins. pH of solutions above 8.5 led to the pronounced leaching of pigments, associated with the lowered redness of cooked shrimp. Shear force of raw and cooked shrimp continuously decreased as pH of solution increased (p<0.05). Solution containing 2.5% NaCl and 2.0% NaHCO3 (pH 8.5) was recommended for treatment of white shrimp as a promising alternative for phosphates to increase the yield and to lower cooking loss without any negative effect on sensory properties.     

Copper in Cultured Shrimp Litopenaeus vannamei and Its Reduction in Hepatopancreas After Exposure to Sublethal Nitrite Levels

Bulletin of Environmental Contamination and Toxicology - This research was to evaluate the load and mobility of Cu in juvenile Litopenaeus vannamei after exposure (48 h) to sublethal concentration...     

Unidirectional Sodium Fluxes and Gill CYP1A Induction in an Amazonian Fish (Hyphessobrycon erythrostigma) Exposed to a Surfactant and to Crude Oil

No abstract available.     

Accumulation and Depuration of Cd and its Effect on the Expressions of Metallothionein and Apoptotic Genes in Litopenaeus vannamei

We investigated cadmium (Cd) accumulation in muscles, gills and hepatopancreas of Litopenaeus vannamei following 48 h exposure to 5.25 mg/L, and depuration of Cd in these tissues on 1, 5 and 15 d post exposure. We also detected the expressions of metallothionein (MT), caspase-3 and p53 in hepatopancreas of shrimp exposed to 0, 5.25 and 10.5 mg/L Cd (the 24 h median lethal concentration, 24 h LC₅₀) at 0, 3, 12, 24 and 48 h. Cd accumulated with high concentration in hepatopancreas, and low concentration in muscles. Cd depurated fast in hepatopancreas and gills. MT expression increased in a time-dependent manner after Cd exposure. The p53 and caspase-3 increased at 12 and 24 h in 10.5 mg/L group. In conclusion, the accumulation and depuration of Cd in three tissues were tissues-specific. The changes of the expressions of MT, p53 and caspase-3, were stress response of L. vannamei under Cd exposure.

     

某厂三硝基甲苯作业工人白内障发病情况调查研究

目的研究三硝基甲苯(TNT)对眼晶状体的损害及其发病情况,探讨有效的预防控制措施。方法对某化工厂187名TNT作业工人眼晶状体损害进行调查。结果TNT白内障检出率为41.71%,性别、工种、年龄、工龄、接触工龄与TNT白内障发生密切相关。结论职业接触吸收主要以TNT的皮肤吸收为主。接触工龄越长,TNT白内障的检出率越高。预防控制TNT职业损害,要进行工艺改革,加强通风排毒,降低车间空气中TNT浓度,采取切实有效的皮肤防护措施。