Mercury in the tissues of five cephalopods species: First data on the nervous system

A study of trophic structure, physiological condition and mercury biomagnification in swordfish (Xiphias gladius): Evidence of unfavourable conditions for the swordfish population in the Western Mediterranean

“…Mercury contamination was found throughout all of the Catalan swordfish prey groups: crustaceans, cephalopods, epi-and bathypelagic teleosts. The THg concentrations found in these organisms were within the range of other studies (Cardoso et al, 2019;Morrison et al, 2015;Minet et al, 2021;Di Beneditto et al, 2021) and were significantly positively correlated to both δ 15 N and δ 13 C. Correlations have also been found by McCormack et al (2020) between THg and δ 13 C, and by Seco et al (2021) between THg and δ 15 N in other top predators. Their importance as a source of food means that cephalopods contribute significantly to the swordfish's mercury intake, not only because of the frequency of consumption and the quantity ingested (individuals are often swallowed whole), but also because of the fairly high levels of mercury recorded in some species of cephalopods (Storelli et al, 2006).…”

Bioaccumulation of inorganic and organic mercury in the cuttlefish Sepia officinalis: Influence of ocean acidification and food type

“…Finally, 203 Hg activities were undetectable in the beak, which is usually used to trace Hg contamination in cephalopods (Queirós et al, 2020), likely due to a low incorporation rate. In contrast, the optic lobes activities were similar to the mantle following the trophic Hg exposure, confirming that nervous tissues are target organ for MeHg accumulation in cephalopods (Minet et al, 2021).…”

“…Among marine organisms, most of the available information on Hg is related to top predators (fish, mammals, and birds) and seafood, due to their high Hg concentrations and their associated risks as an important food source for humans. In contrast, information on Hg in cephalopods is still scarce, despite the fact that these molluscs: 1) are known to efficiently accumulate Hg reaching up to more than 3 µg g -1 dry weight (dw) in muscle (e.g., Barghigiani et al, 2000); 2) have a pivotal place in trophic webs playing a key role in the transfer of Hg to top predators (Jackson et al, 2006;Carravieri et al, 2014) and 3) have a developed central nervous system potentially affected by Hg accumulation (Minet et al, 2021).…”

Chemical Forms of Mercury in Pilot Whales Determined from Species-Averaged Mercury Isotope Signatures

“…Recently, advancement in the application of high energy-resolution X-ray absorption (HR-XANES) spectroscopy in wildlife identified that MeHg is detoxified to nontoxic mercury selenide (HgSe) through an intermediary Hg-tetraselenolate (Hg­(Sec) 4 ) species. − The stepwise transformation of MeHg observed in bird and fish tissues (MeHg → Hg­(Sec) 4 → HgSe), likely initiated by selenoprotein P (SelP), provided the first in vivo mechanistic information for the observation of HgSe in the liver and extrahepatic tissues of marine mammals − and seabirds using standard resolution X-ray absorption spectroscopy and electron microscopy. Although these two techniques provide critical structural information on mercury, − they provide limited insight into biochemical processes essential for understanding the toxicokinetics of toxic MeHg in organisms (i.e., fate, tissue-specific exchange).…”