The protective role of lycopene against toxic effects induced by the herbicide Harness® and its active ingredient acetochlor on the African catfish Clarias gariepinus (Burchell, 1822).

The effects of Harness® toxicity on fish health are little known. So, current work aimed to study the impact of sub-lethal doses of Harness® (an acetochlor-based herbicide) on the African catfish, Clarias gariepinus, and also investigated the potential role of lycopene (LYCO) administration in alleviating Harness® negative effects. Fish were divided into five groups in triplicates as follows: group 1 (control) received no treatment, group 2 was exposed to 10 µm Harness®/L, group 3 was orally administered 10 mg LYCO/kg body weight and exposed to 10 µm Harness®/L, group 4 was exposed to 100 µm Harness®/L, and group 5 was orally administered 10 mg LYCO/kg body weight and exposed to 100 µm Harness®/L for 2 weeks. Some hemato-biochemical parameters, genotoxicity, and histopathological changes were assessed at the end of this period. Sub-lethal doses of Harness® altered the shape of erythrocytes in contrast to the control sample. Also, hematological parameters of exposed fish exhibited a significant (P < 0.05) reduction in the values of red blood cell count (RBCs), hemoglobin (Hb), hematocrit (HCT), and platelets (PL), as well as an insignificant (P > 0.05) drop in mean corpuscular volume (MCV). Harness® was also found to cause genotoxicity as well as histopathological alterations. LYCO administration decreased hemato-biochemical changes and returned them to near-normal levels. The findings showed that LYCO administration (10 mg LYCO/kg body weight) decreased Harness® toxicity in C. gariepinus and alleviated its destructive effects.

The protective role of Spirulina platensis to alleviate the Sodium dodecyl sulfate toxic effects in the catfish Clarias gariepinus (Burchell, 1822).

Sodium dodecyl sulfate (SDS) as anionic surfactant is common in household and personal care products and reach in the aquatic ecosystems from different applications. Present work aimed to study the effects of SDS and the potential ameliorative influence of Spirulina platensis (SP) in the African catfish Clarias gariepinus. Fish was exposed to SDS and SP, individually or in combination in four equal groups for two weeks. The 1st group (control), 2nd group (SDS-treated), 3rd group (SDS, 0.1 mg L-1 + SP, 100 mg L-1 water) and 4th group (SDS, 0.1 mg L-1 + SP, 200 mg L-1). Serum samples were used to analyze hepatic and renal functions, electrolytes, genetic, and antioxidant biomarkers. The results revealed that SDS exposure induced hepatic and renal dysfunction, electrolytes imbalance, as well as significant disruption in enzymatic and non-enzymatic antioxidants, and increase in alterations, micronuclei and apoptosis percentages in erythrocytes. SP addition restored these biochemical and genetic variations close to control levels. Thus, the present study suggests that SP could protect the catfish against SDS-induced injury by scavenging ROS, sustaining the antioxidant status and diminishing DNA oxidative damage.

Contamination and Ecological Hazard Assessment of Heavy Metals in Freshwater Sediments and Oreochromis niloticus (Linnaeus, 1758) Fish Muscles in a Nile River Canal in Egypt.

Heavy metal residues in sediment and Oreochromis niloticus fish muscles, collected from a Nile River Canal (Bahr Shebeen Canal), Egypt, were investigated from September 2014 to December 2015. The spatial and seasonal distributions of Cd, Cu, Fe, Pb, and Zn are described and discussed. Relative abundance of these metals in sediment was found as follows: Fe > Zn > Cu > Pb > Cd. Indices of pollution were used to detect the degree of sediment contamination and indicated elevated concentrations likely to adversely affect benthic and benthic-associated organisms. Anthropogenic activities strongly influenced metal occurrence in sediments. Accumulation of heavy metals in fish muscular tissue was found to be nearly comparable to the sediment. Relative abundance of metals in fish tissue followed the trend of Fe > Zn > Pb > Cu > Cd. Fish can be used as a surrogate for heavy metals pollution. The bioaccumulation factor (BAF) in fish muscle showed the following trend: Pb > Zn > Cu > Fe > Cd. Levels of most selected heavy metals detected in muscular tissue of fish were below admissible limits set by different organizations. However, HI (hazard index) showed that the cumulative risk effects are of considerable concern, especially where fish consumption is high. Consequently, it is recommended that discharged water containing pollutants should be prioritized to include continuous monitoring, and adequate public awareness.

Effects of illegal cyanide fishing on vitellogenin in the freshwater African catfish, Clarias gariepinus (Burchell, 1822).

The effects of cyanide, used in illegal fishing, on one of the most economically important Nile fishes, the African catfish (Clarias gariepinus), were studied. Cyanide impacts were evaluated in terms of biochemical, molecular and histopathological characteristics. After exposure to sublethal concentration (0.05mg/l) of potassium cyanide (KCN) for two and four weeks, GOT (glutamate oxaloacetate transaminase) was significantly increased in both male and female, while GPT (glutamate pyruvate transaminase), total plasma protein, phosphoprotein phosphorus (Vgt) in serum, vitellogenin gene expression (Vtg mRNA) and estrogen receptors (ER mRNA) were significantly decreased in female. On the other hand, male C. gariepinus showed a significant increase in Vtg and Vtg mRNA. Liver, testis and ovaries showed distinct histopathological changes. It was concluded that, cyanide caused damaging effects to fish and can cause serious disturbance in the natural reproduction and a drastic decline in fish population. Therefore, it is recommended that, the use of cyanide compounds must be prohibited to conserve the fisheries resources.

Assessment of metal status in drainage canal water and their bioaccumulation in Oreochromis niloticus fish in relation to human health.

The purpose of this study was to assess metal concentrations (Al, Cd, Pb, Hg and Ni) in Sabal drainage canal (Al-Menoufiya Province, River Nile Delta, Egypt) water as well as their accumulation in some selected organs (skin, muscles and kidneys) of Oreochromis niloticus fish to evaluate their hazard levels in relation to the maximum residual limits for human consumption. Drainage canal water was found to be heavily polluted with metals which far exceeded the permissible limits. It was found that metals accumulated in organs of O. niloticus in concentrations higher than those of canal water. Kidneys of O. niloticus contained the highest concentrations of the detected metals, while skin appeared to be the least preferred site for the bioaccumulation of metals as the lowest metals concentrations were detected in this tissue. The present study shows that fish organs contained high levels of metals exceeding the permissible limits values. Metals in muscle of fish were higher than the maximum permissible concentrations for human consumption. Thus, consuming fish caught from drainage canals is harmful to the consumers.

Metals concentrations in Nile tilapia Oreochromis niloticus () from illegal fish farm in Al-Minufiya Province, Egypt, and their effects on some tissues structures.

This study clarified the suitability of fishes caught from illegal fish farms to human consumption and their hazards to public health. For this purpose, the concentrations of some metals (Al, Cd, Pb, Hg and Ni) in water and Nile tilapia (Oreochromis niloticus) fish samples collected from an illegal fish farm, in addition to pathological conditions of the fish tissues, were examined. The illegal farm water was found to be heavily polluted with metals which far exceeded the permissible limits. It was found that metals accumulated in tissues of O. niloticus in concentrations higher than those of farm water. Kidney of O. niloticus contained the highest concentrations of the detected metals, while muscle and skin contained the lowest concentrations. The examination of fish tissues revealed various histopathological lesions which related directly to the pollution of the illegal farm water. Moreover, metals levels in O. niloticus muscle were higher than the maximum permissible levels for human consumption. Consequently, the flesh of fishes from the illegal farms could be considered hazardous to human health. Therefore, warning against eating fish caught from the illegal fish farms should be announced. Moreover, removal of such illegal fish farms is necessary for the public health protection.

Accumulation and distribution of copper and zinc in both water and some vital tissues of two fish species (Tilapia zillii and Mugil cephalus) of Lake Qarun, Fayoum Province, Egypt.

This study was carried out on Lake Qarun, Fayoum Province, Egypt throughout four seasons, spring 2004 to winter 2005. The concentration of Zn in water as well as in fish organs was always higher than Cu. Correlations between concentration of heavy metals in water and fish organs were elucidated. The concentrations of heavy metals in fish samples indicated that Tilapia zillii were higher than those of Mugil cephalus, which is attributed to their feeding behavior. It was found that these metals have been accumulated in fish organs in different concentrations, which were much higher, several times in some cases, than those found in the surrounding water. The analysis of variance (ANOVA, 1-way analysis) for heavy metals in water and fish organs indicated significant difference. Bioaccumulation factor values showed that the trend of accumulation of metals in fish organs was apparent in liver, gills and muscle, respectively. Lesions deformations were detected and analyzed to clarify the possible role of water pollution on the efficiency of fish and hence the declining fish production of Lake Qarun. The results suggest that the Lake Qarun system is contaminated with heavy metals and the consumption of fishes of the Lake could pose health damage to the local population whose diet consists mainly of fish. A recommendation is given to rescue Lake Qarun from these serious ecological problems.