Maternal and embryonic trace element concentrations and stable isotope fractionation in the smalleye smooth-hound (Mustelus higmani). (October 2020)

• Record Type: Journal Article
• Authors: de Souza-Araujo, Juliana; Andrades, Ryan; de Oliveira Lima, Marcelo; Hussey, Nigel E.; Giarrizzo, Tommaso
• Is Part Of: Chemosphere. Volume 257(2020)
• Publication Date: 2020-10
• Subjects: Amazon -- Elasmobranch -- Maternal offloading -- Trace elements -- Se:Hg molar ratio -- Stable isotopes; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.127183
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Here, we evaluate maternal offloading of 16 trace elements (Essential: Co, Cr, Cu, Fe, Mn, Ni, Se and Zn; Nonessential: Al, As, Ba, Cd, Hg, Pb, Tl and U) and determine mother-offspring isotopic fractionation of δ 13 C and δ 15 N in muscle and liver tissue of four pregnant Mustelus higmani and 18 associated embryos sampled from the Amazon Coast of Brazil. Embryo muscle tissue had significantly higher concentrations of most trace elements when compared to mothers, with the exception of Hg. Embryo liver accumulated more nonessential elements than muscle (n = 7 vs . 0, respectively), while the Se:Hg molar ratio was >1 in liver and muscle of both mothers and embryos. Livers of embryos were moderately enriched in δ 13 C and δ 15 N when compared to that of their mother. Negative correlations were observed between embryo body length and δ 13 C and trace elements concentrations. We conclude that mothers offload a large portion of all essential elements and Al, As and Pb to their young and that the isotopic fractionation of embryos reflects maternal diet and habitat occupied, with δ 13 C diluted with embryonic growth. We also show that muscle and liver accumulate trace elements at different rates relative to the body length of embryos. The Se:Hg molar ratio suggests that Se could play a protective role against Hg toxicity during early stages of M. higmani embryonic development. Highlights: Mothers offload essential and nonessential elements to their young. Element concentrations were typically higher in liver then in muscle, with the exception of Hg. Element and δ 13 C values declined with increasing embryo size. Embryo tissue isotope values reflect mother's diet and foraging location. Se may play a protective role against Hg toxicity.