Liver, gills, and skin histopathology and heavy metal content of the Danube sterlet (Acipenser ruthenus Linnaeus, 1758)

Abstract

The sterlet (Acipenser ruthenus L.) is a bottom-feeding fish species with a direct exposure to contaminants from water and sediments. Although heavy metal pollution is believed to be one of the main threats to the sterlet population in the Danube River basin, there is a lack of knowledge of the exact impact of heavy metals on their survival. In the present study, effects of heavy metal pollution on sterlet in the Danube basin were assessed as well as the utility of different sterlet organs and tissues as indicators of heavy metal contamination. The sterlet were sampled at three different sites in the Danube basin, in Hungary and Serbia, isolated from each other by dams. Heavy metal analysis included measurement of Cd, As, Pb, Cr, Hg, Cu, Ni, Fe, Mn, and Zn concentrations in sterlet gills, muscle, liver, and intestine, and histopathological analyses comprised assessment and scoring of the extent and intensity of alterations in skin, gills, and liver tissue. Analysis revealed a significant presence of sublethal histopathological changes that were most pronounced in the liver and skin and increased accumulation of heavy metals, with the highest concentrations in the liver. Canonical discriminant analysis showed significant differentiation among the three studied localities, suggesting that the heavy metal concentrations in sterlet populations were site specific. The present study concludes that the accumulation of heavy metals is a response to the presence of these pollutants in the environment, and, together with other pollutants, it affects the vital organs of natural sterlet populations.

Concentrations of 17 elements in muscle, gills, liver and gonads of five economically important fish species from the Danube River

“…This is in line with the findings of Jeng and Sun (1981) and Liao et al (2006) that Zn concentrations in common carp digestive tract are always >10 times higher than in most of the animal tissues. Our results are in accordance with the findings of other authors, namely that the highest elemental concentrations are accumulated in metabolically active tissues such as liver and gills (Rashed, 2001;Dural et al, 2006;Erdogrul and Erbilir, 2007;Kenšova et al, 2010;Poleksić et al, 2010), while muscles commonly have lower elemental concentrations (Çalta and Canpolat, 2006;Ploetz et al, 2007;Agah et al, 2009). Fish liver accumulates the highest Cu levels (Rashed, 2001), since Cu represents an inherent part of the enzymes localized in the liver (Kenšova et al, 2010).…”

“…In that sense, our study provides valuable information, as all studied fish species also represent major object of commercial fishery in the Danube in Serbia. Moreover, since elemental concentrations in fish organs depend on the actual level of the pollution in the waterbody they inhabit, studies of elemental accumulation in fish tissues are also able to indicate the actual elemental levels in the environment (Çalta and Canpolat, 2006;Poleksić et al, 2010).…”

Heavy metals levels in fish from aquaculture farms and risk assessment in Lhasa, Tibetan Autonomous Region of China

“…Our results implied the muscle generally had lower accumulation capacity for heavy metal than the other tissues, which is in accordance with findings in sterlet (Acipenser ruthenus) and Pontic shad (Alosa immaculate) (Poleksic et al 2010;Visnjic-Jeftic et al 2010;Jaric et al 2011). …”

Riverine Ecosystem Management

“…As sturgeons can produce fertile offspring through interspecific hybridization, the introduction of nonnative sturgeon species or genotypes can lead to an outbreeding depression of native stocks, as already to some extent described in Ludwig et al (2009). Due to their longevity and their benthic habitat, sturgeons are also sensitive to pollution and the effects of accumulated heavy metals in the sediments, which may lead to organ dysfunctions, especially affecting the gonads and reducing fertility (Jarić et al 2011;Poleksic et al 2010).…”