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Concentrations of trace elements in a rare and threatened coastal shark from the Arabian Gulf (smoothtooth blacktip Carcharhinus leiodon)
2015
Moore, Alec B.M. | Bolam, Thi | Lyons, Brett P. | Ellis, Jim
Kuwait’s waters are one of only two locations where the smoothtooth blacktip shark Carcharhinus leiodon is known to occur. Concentrations of 11 trace elements were analysed in five juvenile and two adult specimens of this coastal predator. Concentrations of lead in muscle increased with length, whilst manganese concentration decreased. Arsenic concentrations in muscle were among the highest reported in elasmobranchs, and the concentration in the liver increased significantly in relation to length. In comparison to published literature, concentrations of manganese (liver), lead (muscle) and iron (muscle and liver) were high. Mercury concentrations in the muscle exceeded European Food Safety Authority limits and were among the highest reported in any elasmobranch. Concentrations of selenium, which may inhibit mercury toxicity, were also high. These results and previous studies indicate that potentially hazardous levels of mercury and other contaminants may occur in sharks in this region, adding further stressors to these vulnerable populations.
اظهر المزيد [+] اقل [-]First report on metal and metalloid contamination of Ampullae of Lorenzini in sharks: A case study employing the Brazilian sharpnose shark Rhizoprionodon lalandii from Southeastern Brazil as an ecotoxicological model
2022
Willmer, Isabel Quental | Wosnick, Natascha | Rocha, Rafael Christian Chávez | Saint'Pierre, Tatiana Dillenburg | Vianna, Marcelo | Hauser-Davis, Rachel Ann
Metal contamination has never been assessed in Ampullae of Lorenzini. This study employed Rhizoprionodon lalandii, as an ecotoxicological model to investigate potential metal accumulation in Ampullae of Lorenzini jelly. No differences between sexes were observed regarding jelly metal concentrations at Rio das Ostras (RJ) or Santos (SP). Statistically significant correlations were noted between total lengths (TL) and condition factors and several metals at both sampling sites, demonstrating the potential for Chondrichthyan sensory capacity disruption and possible effects on foraging success. Maternal metal transfer to Ampullae jelly was confirmed. Rhizoprionodon lalandii is thus, a good model to assess Ampullae of Lorenzini contamination, as this electrosensory organ seems to be highly vulnerable to metal contamination.
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